Difference between revisions of "Input syntax manual"

Revision as of 16:45, 7 January 2019 (view source)

Latest revision as of 14:12, 30 August 2023 (view source)

(→‎det (detector definition))

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''"Serpent – a Continuous-energy Monte Carlo Reactor Physics Burnup Calculation Code."'' [http://montecarlo.vtt.fi/download/Serpent_manual.pdf User manual], June 18, 2015.</ref>.

−

== Input cards ==

+

== Input cards ==

NOTE: Serpent command words are in <tt>'''boldface'''</tt> and input parameters entered by the user in <tt>''CAPITAL ITALIC''</tt>. Optional input parameters are enclosed in [ square brackets ], and when the number of values is not fixed, the remaining values are marked with three dots (...).

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=== branch (branch definition) ===

−

'''branch''' ''NAME'' [ '''repm''' ''MAT1'' ''MAT2'' ]

+

'''branch''' ''NAME'' [ [[#branch_repm|'''repm''']] ''MAT1'' ''MAT2'' ]

−

[ '''repu''' ''UNI1'' ''UNI2'' ]

+

[ [[#branch_repu|'''repu''']] ''UNI1'' ''UNI2'' ]

−

[ '''stp''' ''MAT DENS TEMP THERM1 SABL1 SABH1 THERM2 SABL2 SABH2 ...'' ]

+

[ [[#branch_stp|'''stp''']] ''MAT DENS TEMP THERM1 SABL1 SABH1 THERM2 SABL2 SABH2 ...'' ]

−

[ '''tra''' ''TGT TRANS'' ]

+

[ [[#branch_tra|'''tra''']] ''TGT TRANS'' ]

−

[ '''xenon''' ''OPT'' ]

+

[ [[#branch_xenon|'''xenon''']] ''OPT'' ]

−

[ '''samarium''' ''OPT'' ]

+

[ [[#branch_samarium|'''samarium''']] ''OPT'' ]

−

[ '''var''' ''VNAME VAL'' ]

+

[ [[#branch_norm|'''norm''']] ''NSF'' ]

−

Defines the variations invoked for a branch in the automated burnup sequence. ~~Input values~~:

+

[ [[#branch_gcu|'''gcu''']] ''UNI2'' ]

+

[ [[#branch_reptrc|'''reptrc''']] ''FILE1'' ''FILE2'' ]

+

[ [[#branch_var|'''var''']] ''VNAME VAL'' ]

+

[ [[#branch_incl|'''incl''']] ''MODFILE'' ]

+

Defines the variations invoked for a branch in the automated burnup sequence. The first parameter:

{|

| <tt>''NAME''</tt>

| : branch name

−

|-

+

|}

+

The remaining parameters are defined by separate key words followed by the input values.

+

Notes:

+

*The branch card can be combined with the [[#coef (coefficient matrix definition)|coef card]], [[#hisv (history variation matrix definition)|hisv card]], and [[#casematrix (casematrix definition)| casematrix card]].

+

*The branch name identifies the branch <tt>''BRm,i''</tt> in the variation matrix defined by the [[#coef (coefficient matrix definition)|coef card]], [[#hisv (history variation matrix definition)|hisv card]], and [[#casematrix (casematrix definition)| casematrix card]].

+

*The input parameters consist of a number variations, which are invoked when the branch is applied.

+

*A single branch card may include one or several variations.

+

*For more information, see detailed description on the [[automated burnup sequence]].

+

Variation types:

+

Branch material variation (<tt>'''repm'''</tt>):

+

{|

| <tt>''MAT1''</tt>

| : name of the replaced material

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| <tt>''MAT2''</tt>

| : name of the replacing material

−

|-

+

|}

+

Notes:

+

*The material variation can be used to replace one material with another, for example, to change coolant boron concentration.

+

*The material replacement works as if <tt>''MAT1''</tt> were created using the [[#mat_.28material_definition.29|mat]] or [[#mix_.28mixture_definition.29|mix]] card of <tt>''MAT2''</tt>.

+

*The name of the material present in the geometry will still be <tt>''MAT1''</tt> after the replacement, but the material specification (composition, density, tmp, moder, rgb, etc.) will correspond to <tt>''MAT2''</tt>.

+

**This means that all other input-cards that are linked to a specific material name such as '''dm''' entry in the [[#det_dm|det card]], '''sm''' entry in the [[#src_sm|src card]], [[#set_trc|set trc]] option and/or [[#set_iter_nuc|set iter nuc]] option can be linked to the original material (<tt>''MAT1''</tt>) and they will automatically apply to whatever material <tt>''MAT2''</tt> replaces <tt>''MAT1''</tt> for the branch calculation.

+

*The replaced material ''MAT1'' is also replaced inside mixtures.

+

**This means one can not replace a material with a mixture defined with [[#mix (mixture_definition)|mix card]] containing the replaced material (for example replacing pure water defined with [[#mat (material definition)|mat card]] by a mixture of boron and water defined with a [[#mix (mixture definition)|mix card]] containing the same pure water material).

+

*The replacing material ''MAT2'' can not be included in the geometry using other cards than the branch card, from version 2.1.30 and on.

+

Branch universe variation (<tt>'''repu'''</tt>):

+

{|

| <tt>''UNI1''</tt>

| : name of the replaced universe

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| <tt>''UNI2''</tt>

| : name of the replacing universe

−

|-

+

|}

+

Notes:

+

*The universe variation can be used to replace one universe with another, for example, to replace empty control rod guide tubes with rodded tubes for control rod insertion in 2D geometries.

+

*The name of the universe present in the geometry will still be <tt>''UNI1''</tt> after the replacement, but the universe contents will correspond to <tt>''UNI2''</tt>.

+

*This means that all other input-cards that are linked to a specific universe name such as '''du''' entry in the [[#det_du|det card]] and/or '''su''' entry in the [[#src_su|src card]] can be linked to the original universe (<tt>''UNI1''</tt>) and they will automatically apply to whatever universe <tt>''UNI2''</tt> replaces <tt>''UNI1''</tt> for the branch calculation.

+

Branch state variation, density/temperature (<tt>'''stp'''</tt>):

+

{|

| <tt>''MAT''</tt>

| : name of the material for which density and temperature are adjusted

|-

| <tt>''DENS''</tt>

−

| : material density after adjustment (positive ~~entries for~~ atomic, negative ~~entries for~~ mass ~~densities, or "sum" to use the sum of the constituent nuclide densities~~)

+

| : material density after adjustment (positive value = atomic density [in b-1cm-1], negative value = mass density [in g/cm3])

|-

| <tt>''TEMP''</tt>

−

| : material temperature after adjustment~~, or -1 if no adjustment~~ in ~~temperature~~

+

| : material temperature after adjustment [in K]

|-

| <tt>''THERMn''</tt>

−

| : ''n~~:th~~'' thermal scattering data associated with the material

+

| : ''n''-th thermal scattering data associated with the material

|-

| <tt>''SABLn''</tt>

−

| : name of the ''n'':th S(~~<math>\~~alpha,\beta~~</math>~~) library for temperature below the given value

+

| : name of the ''n''-th S(α, β) library for temperature below the given value

|-

| <tt>''SABHn''</tt>

−

| : name of the ''n'':th S(~~<math>\~~alpha,\beta~~</math>~~) library for temperature above the given value

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| : name of the ''n''-th S(α, β) library for temperature above the given value

−

|-

+

|}

+

Notes:

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*The state variation can be used to change material density and temperature.

+

*There is a special entry for the <tt>''TEMP''</tt> parameter:

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**"<tt>-1</tt>": to not adjust temperature

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*There are two special entries for the <tt>''DENS''</tt> parameter:

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** "<tt>sum</tt>": to define the material density as the sum of the constituent nuclides densities (not supported from version 2.2.0 and on)

+

** "<tt>original</tt>": to keep unmodified the material density (introduced in version 2.2.1).

+

*The adjustment is made using the built-in [[Doppler-broadening preprocessor routine]] and tabular interpolation for S(α, β) thermal scattering data.

+

*The last three parameters of the card are provided only if the material has thermal scattering libraries attached to it (see the [[#therm (thermal scattering library definition)|therm card]]).

+

Branch transformation variation (<tt>'''tra'''</tt>):

+

{|

| <tt>''TGT''</tt>

| : target universe, surface or cell

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| <tt>''TRANS''</tt>

| : name of the applied transformation

−

|-

+

|}

+

Notes:

+

*The transformation variation can be used to move or rotate different parts of the geometry, for example, to adjust the position of control rods in 3D geometries.

+

*The name of the transformation <tt>''TRANS''</tt> refers to the unit (universe, cell or surface) entry in the [[#trans (transformations)|trans card]].

+

Branch xenon variation (<tt>'''xenon'''</tt>):

+

{|

| <tt>''OPT''</tt>

−

| : option for setting poison concentrations (0 = set to zero, 1 = use values from restart file)

+

| : option for setting xenon poison concentrations (0 = set to zero, 1 = use values from restart file)

+

|}

+

Notes:

+

*The xenon variation can be set to enforced the Xe-135 and Xe-135m concentrations and optionally I-135 concentration to zero.

+

**By default the concentrations are read from the restart file.

+

*Equilibrium xenon ([[#set_xenon|set xenon]] option).

+

**If the calculation is "<tt>on</tt>", then the option "<tt>0</tt>" sets I-135, Xe-135 and Xe-135m concentrations to zero.

+

**If the calculation is "<tt>off</tt>", then the option "<tt>0</tt>" sets only Xe-135 and Xe-135m concentrations to zero.

+

Branch samarium variation (<tt>'''samarium'''</tt>):

+

{|

+

| <tt>''OPT''</tt>

+

| : option for setting samarium poison concentrations (0 = set to zero, 1 = use values from restart file)

+

|}

+

Notes:

+

*The samarium variation can be set to enforce the Sm-149 concentration and possibly Pm-149 concentration to zero.

+

**By default the concentrations are read from the restart file.

+

*Equilibrium samarium ([[#set_samarium|set samarium]] option):

+

**If the calculation is "<tt>on</tt>", then the option "<tt>0</tt>" sets both Pm-149 and Sm-149 concentrations to zero.

+

**If the calculation is "<tt>off</tt>", then the option "<tt>0</tt>" sets only Sm-149 concentration to zero.

+

Branch normalization variation (<tt>'''nsf'''</tt>):

+

{|

+

| <tt>''NSF''</tt>

+

| : normalization scaling factor

+

|}

+

Notes:

+

*The normalization variation can be used to change the normalization.

+

*The adjustment is made applying the parameter ''NSF'' as a multiplicative scaling factor to the given normalization.

+

Branch group constant variation (<tt>'''gcu'''</tt>):

+

{|

+

| <tt>''UNI2''</tt>

+

|: name of the replacing universe

+

|}

+

Notes:

+

*The group constant variation can be used to replace the universe for group constant generation.

+

*The variation is limited to a single-valued GCU-list (see [[#set gcu|set gcu]] option).

+

Branch transport-correction variation (<tt>'''reptrc'''</tt>):

+

{|

+

| <tt>''FILE1''</tt>

+

| : file path of the replaced transport correction curve data

|-

+

| <tt>''FILE2''</tt>

+

| : file path of the replacing transport correction curve data

+

|}

+

Notes:

+

*The transport-correction variation can be used to replace a transport correction file with another (see [[#set trc|set trc]] option).

+

Branch variable variation (<tt>'''var'''</tt>):

+

{|

| <tt>''VNAME''</tt>

| : variable name

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Notes:

+

*The variable variation can be used to pass information into the output file, which may be convenient for the post-processing of the data.

−

*The branch name identifies the branch in the coefficient matrix of the [[#coef (coefficient matrix definition)|coef card]]

−

*The input parameters consist of a number variations, which are invoked when the branch is applied. A single branch card may inclued one or several variations.

−

*The '''repm''' variation can be used to replace one material with another, for example, to change coolant boron concentration.

−

*The '''repu''' variation can be used to replace one universe with another, for example, to replace empty control rod guide tubes with rodded tubes for control rod insertion in 2D geometries.

−

*The '''stp''' variation can be used to change material density and temperature. The adjustment is made using the built-in [[Doppler-broadening preprocessor routine]] and tabular interpolation for S(<math>\alpha,\beta</math>) thermal scattering data.

−

*The last three parameters of the '''stp''' entry are provided only if the material has thermal scattering libraries attached to it (see the [[#therm (thermal scattering library definition)|therm card]]).

−

*The '''tra''' variation can be used to move or rotate different parts of the geometry, for example, to adjust the position of control rods in 3D geometries. The name of the transformation refers to the unit (universe, cell or surface) entry in the [[#trans (transformations)|trans card]].

−

*The '''xenon''' and '''samarium''' options can be set to enforce the concentrations of fission product poisons Xe-135 and Sm-149 to zero. By default the concentrations are read from the restart file.

−

*Variables can be used to pass information into output file, which may be convenient for the post-processing of the data.

−

*The branch card is used together with the [[#coef (coefficient matrix definition)|coef card]].

−

*For more information, see detailed description on the [[automated burnup sequence]].

−

*The replaced material MAT1 of repm variation is also replaced inside mixtures. This means one can not replace a material with a mixture defined with [[#mix (mixture_definition)|mix card]] containing the replaced material (for example replacing pure water defined with mat card by a mixture of boron and water defined with a mix card containing the same pure water material).

−

*Currently (version 2.1.30) the replacing material MAT2 of repm variation can not be included in geometry using other cards than the branch card with the repm variation.

−

~~=== cell~~ (~~cell definition~~) ~~===~~

+

Branch user-defined variation (<tt>'''incl'''</tt>):

+

{|

+

| <tt>''MODFILE''</tt>

+

|: file path to an additional/modified input file

+

|}

−

~~'''cell''' ''NAME UNI~~<~~sub~~>0</~~sub~~> ~~MAT'' [ ''SURF~~<~~sub>1</sub~~>'' ''~~SURF2~~</~~sub~~>~~'' ..~~. ]

+

Notes:

+

*The user-defined variation can be used as a multi-purpose option to modify the base-input via the additional input file <tt>''MODFILE''</tt>.

−

Defines ~~a material cell~~. Input values:

+

=== casematrix (casematrix definition) ===

+

'''casematrix''' ''CASE_NAME''

+

''NHIS'' [ ''HIS_BR1'' ''HIS_BR2'' ... ''HIS_BRNHIS'' ]

+

''NBU'' [ ''BU1'' ''BU2'' ... ''BUNBU'' ]

+

''NBR1'' [ ''BR1,1'' ''BR1,2'' ... ''BR1,NBR1'' ]

+

''NBR2'' [ ''BR2,1'' ''BR2,2'' ... ''BR1,NBR2'' ]

+

...

+

Defines the casematrix for the automated burnup sequence. Input values:

{|

−

| <tt>''~~NAME~~''</tt>

+

| <tt>''CASE_NAME''</tt>

−

| : ~~cell~~ name

+

| : name of the casematrix

|-

−

| <tt>''~~UNI0~~''</tt>

+

| <tt>''NHIS''</tt>

−

| : ~~universe where the cell belongs to~~

+

| : number of history variations

|-

−

| <tt>''~~MAT~~''</tt>

+

| <tt>''HIS_BRk''</tt>

−

| : ~~material that fills~~ the ~~cell~~

+

| : name of the ''k''-th history variation branch

|-

−

| <tt>''~~SURFn''</tt>~~

+

| <tt>''NBU''</tt>

−

~~| : surface list~~

+

| : number of burnup points

−

|}

+

−

+

−

~~'''cell''' ''NAME UNI0'' '''fill''' ''UNI1'' [ ''SURF1'' ''SURF2'' ... ]~~

+

−

+

−

~~Defines a filled cell. Input values:~~

+

−

+

−

{|

+

−

~~| <tt>''NAME~~''</tt>

+

−

| : ~~cell name~~

+

|-

−

| <tt>''~~UNI~~0''</tt>

+

| <tt>''BUn''</tt>

−

| : ~~universe where~~ the ~~cell belongs to~~

+

| : burnup steps at which the momentary variation branches are invoked (positive value = burnup [in MWd/kg], negative value = time [in d])

|-

−

| <tt>''~~UNI~~1''</tt>

+

| <tt>''NBRm''</tt>

−

| : ~~universe that fills~~ the ~~cell~~

+

| : number branches in the ''m''-th dimension of the burnup matrix

|-

−

| <tt>''~~SURF~~n''</tt>

+

| <tt>''BRm,i''</tt>

−

| : ~~surface list~~

+

| : name of the ''i''-th branch in the ''m''-th dimension

|}

−

'''~~cell~~''' ''~~NAME UNI~~0'' '''~~outside~~''' [ ''SURF1'' ''SURF2'' ... ]

+

Notes:

+

*The casematrix card performs multiple depletions with <tt>''NHIS''</tt> (different) historical variations and performs restarts similar as the [[#coef|coef]] input card.

+

*The casematrix card creates a multi-dimensional coefficient matrix (of size <tt>''NBR1''</tt> × <tt>''NBR2''</tt> × <tt>''NBR3''</tt> × ... ).

+

**The automated burnup sequence performs a restart for each of the listed burnup points, and loops over the branch combinations defined by the coefficient matrix.

+

**This is repeated for each different depletion history.

+

*The casematrix card is used together with the [[#branch (branch definition)|branch card]] and [[Installing_and_running_Serpent#Running_casematrix_calculations|<tt>''-casematrix''</tt>]] command line option.

+

*Multiple casematrix cards can be given in a single input file.

+

*For more information, see detailed description on [[automated burnup sequence]].

+

=== cell (cell definition) ===

+

'''cell''' ''NAME UNI0 MAT'' [ ''SURF1'' ''SURF2'' ... ]

−

Defines ~~an outside~~ cell. Input values:

+

Defines a cell. Input values:

{|

Line 142:

Line 280:

| <tt>''UNI0''</tt>

| : universe where the cell belongs to

+

|-

+

| <tt>''MAT''</tt>

+

| : material that fills the cell

|-

| <tt>''SURFn''</tt>

Line 148:

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Notes:

−

+

*The cell definition is based on the universe-based geometry type in Serpent.

−

*~~There~~ are ~~three types of cells: material cells~~, ~~filled cells and outside cells~~. ~~Filled cells are identified~~ by ~~providing~~ the ~~key word~~ <tt>''~~'fill'~~''</tt>, ~~followed by the~~ universe ~~filling the cell~~. If the ~~key word is missing,~~ the ~~third entry is interpreted~~ as the ~~material filling~~ the cell. ~~Outside cells are identified~~ by ~~replacing the~~ material ~~name with key word~~ <tt>'''~~outside~~'''</tt>.

+

*Universes are implicitly declared, e.g., by using the <tt>''UNI0''</tt> key word on cell cards, as there is no explicit universe input card.

−

*Void cells can be defined by ~~setting~~ the ~~material name to~~ "~~void~~"

+

*The surface list defines the boundaries of the cell by listing the surface names (as provided in the surface definition, [[#surf (surface definition)|surf card]]), together with the operator identifiers (nothing for intersection, ":" for union, "-" for complement and "#" for cell complement).

+

*The general cell definition (so-called "material cell") have tailored types, defined by special material entries (replacing <tt>''MAT''</tt>):

+

::{| class="wikitable" style="text-align: left;"

+

! Type

+

! Description

+

|-

+

| <tt>void</tt>

+

| region is defined as zero-collision

+

|-

+

| <tt>fill ''UNI1''</tt>

+

| region is filled by another universe, <tt>''UNI1''</tt>

+

|-

+

| <tt>outside</tt>

+

| region is not part of the actual geometry ("outside world")

+

|-

+

|}

+

::Outside cells:

+

::*When the particle enters an outside cell, the boundary conditions are applied (see [[#set bc|set bc]] option). It is important that the geometry model is non-re-entrant (convex) when vacuum boundary conditions are used. Delta-tracking might miss the boundary conditions in a re-entrant (concave) outer surface.

+

::*Outside cells are allowed only in the root universe. It is important that all space outside the model is defined.

+

*Cells defined without surfaces are treated as infinite, from version 2.1.32 on.

*When the geometry is set up, the root universe must always be defined. By default the root universe is named "0", and it can be changed with the [[#set root|set root]] option.

−

*Outside cells are used to define the part of the geometry that does not belong to the model. When the particle enters an outside cell, [[#set bc|boundary conditions]] are applied. It is important that the geometry model is non-re-entrant when vacuum boundary conditions are used.

−

*Outside cells are allowed only in the root universe. It is important that all space outside the model is defined.

−

*The surface list defines the boundaries of the cell by listing the surface names (as provided in the [[#surf (surface definition)|surface card]]), together with the operator identifiers (nothing for intersection, ":" for union, "-" for complement and "#" for cell complement).

−

*Universes are implicitly declared for example by using the <tt>''UNI0''</tt> key words on cell cards as there is no explicit universe input card.

*For more information, see detailed description on the [[universe-based geometry type in Serpent]].

Line 171:

Line 327:

|-

| <tt>''BUn''</tt>

−

| : burnup steps at which the branches are invoked

+

| : burnup steps at which the branches are invoked (positive value = burnup [in MWd/kg], negative value = time [in d])

|-

| <tt>''NBRm''</tt>

−

| : number branches in the ''m'':th dimension of the burnup matrix

+

| : number branches in the ''m''-th dimension of the burnup matrix

|-

| <tt>''BRm,i''</tt>

−

| : name of the ''i'':th branch in the ''m'':th dimension

+

| : name of the ''i''-th branch in the ''m''-th dimension

|}

Notes:

−

*The coef card creates a multi-dimensional coefficient matrix (of size <tt>''NBR1''</tt> ~~<math>\~~times~~</math>~~ <tt>''NBR2''</tt> ~~<math>\~~times~~</math>~~ <tt>''NBR3''</tt> ~~<math>\~~times~~</math>~~ ... ). The automated burnup sequence performs a restart for each of the listed burnup points, and loops over the branch combinations defined by the coefficient matrix.

+

*The coef card creates a multi-dimensional coefficient matrix (of size <tt>''NBR1''</tt> × <tt>''NBR2''</tt> × <tt>''NBR3''</tt> × ... ).

−

*Positive values in the burnup vector are interpreted as (MWd/kgU), negative values are interpreted as time steps in days.

+

**The automated burnup sequence performs a restart for each of the listed burnup points, and loops over the branch combinations defined by the coefficient matrix.

−

*The coef card is used together with the [[#branch (branch definition)|branch card]]

+

*The coef card is used together with the [[#branch (branch definition)|branch]] card.

+

*For multiple historical variations or historical conditions defined using a [[#branch (branch definition)|branch]] card, see the [[#casematrix (casematrix definition)|casematrix]] card.

*For more information, see detailed description on [[automated burnup sequence]].

+

=== datamesh (general data mesh definition) ===

+

'''datamesh''' ''NAME'' ''TYPE'' ''USELC'' [ ... ]

+

Defines a general data mesh to be used for spacial discretisation. Input values:

+

{|

+

| <tt>''NAME''</tt>

+

| : mesh name

+

|-

+

| <tt>''TYPE''</tt>

+

| : mesh type

+

|-

+

| <tt>''USELC''</tt>

+

| : use lowest level coordinates (1/yes) instead of global coordinates (0/no) for the mesh search

+

|-

+

|}

+

The remaining parameters are type-dependent.

+

Notes:

+

*The general data mesh can be used, e.g., with detectors ('''dmesh''' entry in the [[#det|det card]]), interfaces ([[#ifc|ifc card]]), sensitivities ('''opt dmesh''' entry in the [[#sens|sens card]]), etc.

+

*When Serpent makes the mesh search for a specific collision point, it will save the collision mesh cell temporarily so that the cell search is conducted at most once even when scoring multiple estimators using the same mesh.

+

*The nested data meshes (type 9) take the coordinates' level from the <tt>''USELC''</tt> parameter defined in the nested mesh itself and use it in the subsequent sub-meshes, overriding the <tt>''USELC''</tt> parameter defined on those.

+

The available general data mesh types are:

+

::{| class="wikitable" style="text-align: left;"

+

! Type

+

! Description

+

|-

+

| [[#datamesh_1|<tt>1</tt>]]

+

| regular 3D Cartesian mesh

+

|-

+

| [[#datamesh_2|<tt>2</tt>]]

+

| regular 2D cylindrical mesh

+

|-

+

| [[#datamesh_4|<tt>4</tt>]]

+

| regular 3D X-type hexagonal mesh

+

|-

+

| [[#datamesh_5|<tt>5</tt>]]

+

| regular 3D Y-type hexagonal mesh

+

|-

+

| [[#datamesh_6|<tt>6</tt>]]

+

| irregular 3D Cartesian mesh

+

|-

+

| [[#datamesh_8|<tt>8</tt>]]

+

| radially irregular 2D cylindrical mesh

+

|-

+

| [[#datamesh_9|<tt>9</tt>]]

+

| regular nested mesh

+

|-

+

|}

+

The syntax of the available types is as follows:

+

'''datamesh''' ''NAME'' '''1''' ''USELC'' ''NX'' ''XMIN'' ''XMAX'' ''NY'' ''YMIN'' ''YMAX'' ''NZ'' ''ZMIN'' ''ZMAX''

+

{|

+

| <tt>''NX''</tt>

+

| : number of cells in the x-direction

+

|-

+

| <tt>''XMIN''</tt>

+

| : mesh lower x-boundary [in cm]

+

|-

+

| <tt>''XMAX''</tt>

+

| : mesh higher x-boundary [in cm]

+

|-

+

| <tt>''NY''</tt>

+

| : number of cells in the y-direction

+

|-

+

| <tt>''YMIN''</tt>

+

| : mesh lower y-boundary [in cm]

+

|-

+

| <tt>''YMAX''</tt>

+

| : mesh higher y-boundary [in cm]

+

|-

+

| <tt>''NZ''</tt>

+

| : number of cells in the z-direction

+

|-

+

| <tt>''ZMIN''</tt>

+

| : mesh lower z-boundary [in cm]

+

|-

+

| <tt>''ZMAX''</tt>

+

| : mesh higher z-boundary [in cm]

+

|}

+

'''datamesh''' ''NAME'' '''2''' ''USELC'' ''NR'' ''RMIN'' ''RMAX'' ''NPHI''

+

{|

+

| <tt>''NR''</tt>

+

| : number of cells in the radial direction

+

|-

+

| <tt>''RMIN''</tt>

+

| : mesh inner radial boundary [in cm]

+

|-

+

| <tt>''RMAX''</tt>

+

| : mesh outer radial boundary [in cm]

+

|-

+

| <tt>''NPHI''</tt>

+

| : number of cells in the polar angle direction

+

|}

+

[[File:Hex lattice x index.png|frame|X-type hexagonal mesh horizontal indexing example for NX = NY = 3.]]

+

'''datamesh''' ''NAME'' '''4''' ''USELC'' ''X0'' ''Y0'' ''PITCH'' ''ZMIN'' ''ZMAX'' ''NX'' ''NY'' ''NZ''

+

{|

+

| <tt>''X0''</tt>

+

| : mesh horizontal origin x-coordinate [in cm]

+

|-

+

| <tt>''Y0''</tt>

+

| : mesh horizontal origin y-coordinate [in cm]

+

|-

+

| <tt>''PITCH''</tt>

+

| : mesh horizontal pitch (equal to cell flat-to-flat width) [in cm]

+

|-

+

| <tt>''ZMIN''</tt>

+

| : mesh lower z-boundary [in cm]

+

|-

+

| <tt>''ZMAX''</tt>

+

| : mesh higher z-boundary [in cm]

+

|-

+

| <tt>''NX''</tt>

+

| : number of cells in the x-direction

+

|-

+

| <tt>''NY''</tt>

+

| : number of cells in the y-direction

+

|-

+

| <tt>''NZ''</tt>

+

| : number of cells in the z-direction

+

|}

+

[[File:Hex lattice y index.png|frame|Y-type hexagonal mesh horizontal indexing example for NX = NY = 3.]]

+

'''datamesh''' ''NAME'' '''5''' ''USELC'' ''X0'' ''Y0'' ''PITCH'' ''ZMIN'' ''ZMAX'' ''NX'' ''NY'' ''NZ''

+

{|

+

| <tt>''X0''</tt>

+

| : mesh horizontal origin x-coordinate [in cm]

+

|-

+

| <tt>''Y0''</tt>

+

| : mesh horizontal origin y-coordinate [in cm]

+

|-

+

| <tt>''PITCH''</tt>

+

| : mesh horizontal pitch (equal to cell flat-to-flat width) [in cm]

+

|-

+

| <tt>''ZMIN''</tt>

+

| : mesh lower z-boundary [in cm]

+

|-

+

| <tt>''ZMAX''</tt>

+

| : mesh higher z-boundary [in cm]

+

|-

+

| <tt>''NX''</tt>

+

| : number of cells in the x-direction

+

|-

+

| <tt>''NY''</tt>

+

| : number of cells in the y-direction

+

|-

+

| <tt>''NZ''</tt>

+

| : number of cells in the z-direction

+

|}

+

'''datamesh''' ''NAME'' '''6''' ''USELC'' ''NX'' ''NY'' ''NZ'' ''X1'' ... ''XNX+1'' ''Y1'' ... ''YNY+1'' ''Z1'' ... ''ZNZ+1''

+

{|

+

| <tt>''NX''</tt>

+

| : number of cells in the x-direction

+

|-

+

| <tt>''NY''</tt>

+

| : number of cells in the y-direction

+

|-

+

| <tt>''NZ''</tt>

+

| : number of cells in the z-direction

+

|-

+

| <tt>''Xi''</tt>

+

| : <tt>''NX'' + 1</tt> mesh boundaries in the x-direction [in cm]

+

|-

+

| <tt>''Yi''</tt>

+

| : <tt>''NY'' + 1</tt> mesh boundaries in the y-direction [in cm]

+

|-

+

| <tt>''Zi''</tt>

+

| : <tt>''NZ'' + 1</tt> mesh boundaries in the z-direction [in cm]

+

|}

+

'''datamesh''' ''NAME'' '''8''' ''USELC'' ''NR'' ''NPHI'' ''R1'' ... ''RNR+1''

+

{|

+

| <tt>''NR''</tt>

+

| : number of cells in the radial direction

+

|-

+

| <tt>''NPHI''</tt>

+

| : number of cells in the polar angle direction

+

|-

+

| <tt>''Ri''</tt>

+

| : <tt>''NR'' + 1</tt> mesh boundaries in the radial direction [in cm]

+

|}

+

'''datamesh''' ''NAME'' '''9''' ''USELC'' ''NLEVEL'' ''MESH1'' ... ''MESHNLEVEL''

+

{|

+

| <tt>''NLEVEL''</tt>

+

| : number of nested levels in this mesh

+

|-

+

| <tt>''MESHi''</tt>

+

| : sub mesh to use at level ''i''

+

|}

=== dep (depletion history) ===

Line 202:

Line 566:

The possible step types are:

−

{| class="wikitable" style="text-align: left;"

+

::{| class="wikitable" style="text-align: left;"

! Type

! Description

Line 250:

Line 614:

Notes:

−

*~~Transport cycle~~ is ~~omitted with~~ the <tt>~~decstep~~</tt> and <tt>~~dectot~~</tt> ~~options.~~

+

*Depletion calculations (burnup/activation steps) require normalization.

−

*Transport cycle is run only once with ~~the~~ <tt>~~actstep~~</tt> and <tt>~~acttot~~</tt> ~~options~~.

+

+

**If the normalization is set to zero, physical estimates, e.g., detectors will be printed as zero.

+

***Alternatively, use a very small value to enforce a non-zero normalization.

+

**Except:

+

***Radioactive decay source: source rate normalization is carried out automatically based on the total emission rate.

+

***Decay steps: equivalent, e.g., zero power.

+

*Activation step, "<tt>actstep</tt>" and "<tt>acttot</tt>":

+

**Transport cycle is run only once and transmutation cross sections are not updated.

+

**Limitations:

+

***It must be preceeded by a burnup step.

+

***It cannot be used with a burnable material radioactive source.

+

***Burnup is not calculated correctly

+

*Decay step, "<tt>decstep</tt>" and "<tt>dectot</tt>":

+

**Transport cycle is omitted and transmutation cross sections are not calculated.

+

**Limitations:

+

***It cannot preceed activation steps.

+

***Physical estimates, e.g., detectors will not be printed for the given step (value zero) due to normalization

−

'''dep''' '''pro''' ''~~PTR_REPROC~~''

+

'''dep''' '''pro''' ''REP_NAME'' ''STYPE'' [ ''STEP1 STEP2 ...'' ]

+

Links a reprocessor to the depletion calculation. Input values:

+

{|

+

| <tt>''REP_NAME''</tt>

+

| : reprocessor name

+

|-

+

| <tt>''STYPE''</tt>

+

| : step type

+

|-

+

| <tt>''STEPn''</tt>

+

| : depletion step list

+

|}

+

Notes:

+

*The reprocessing system or reprocessor controller is defined using the [[#rep|rep card]].

'''dep''' '''bra''' ''PTR_BRANCH''

Line 269:

Line 665:

[ [[#det_dy|'''dy''']] ''YMIN'' ''YMAX'' ''NY'' ]

[ [[#det_dz|'''dz''']] ''ZMIN'' ''ZMAX'' ''NZ'' ]

−

[ [[#~~det_dn~~|'''dn''']] ''TYPE'' ''MIN1'' ''MAX1'' ''N1'' ''MIN2'' ''MAX2'' ''N2'' ''MIN3'' ''MAX3'' ''N3'' ]

+

[ [[#det_dn1|'''dn''']] ''TYPE'' ''MIN1'' ''MAX1'' ''N1'' ''MIN2'' ''MAX2'' ''N2'' ''MIN3'' ''MAX3'' ''N3'' ]

+

[ [[#det_dn2|'''dn''']] ''TYPE'' ''N1'' ''N2'' ''N3'' ''LIM11''...''LIM1N+1'' ''LIM21''...''LIM2N+1'' ''LIM31''...''LIM3N+1'' ]

[ [[#det_dh|'''dh''']] ''TYPE'' ''X0'' ''Y0'' ''PITCH'' ''N1'' ''N2'' ''ZMIN'' ''ZMAX'' ''NZ'' ]

[ [[#det_dumsh|'''dumsh''']] ''UNI'' ''NC'' ''CELL0'' ''BIN0'' ''CELL1'' ''BIN1'' ... ]

Line 283:

Line 680:

[ [[#det_da|'''da''']] ''MAT'' ''FLX'' ]

[ [[#det_dfet|'''dfet''']] ''TYPE'' ''PARAMS'' ]

−

Detector definition. The first ~~parameter~~:

+

[ [[#det_dphb|'''dphb''']] ''PHB'' ]

+

[ [[#det_dmesh|'''dmesh''']] ''MESH'' ]

+

Detector definition. The two first parameters:

{|

+

| <tt>''NAME''</tt>

+

| : detector name

+

|-

| <tt>''PART''</tt>

| : particle type (n = neutron, p = photon)

|}

−

~~is optional in single particle simulations.~~ The remaining parameters are defined by separate key words followed by the input values.

+

The remaining parameters are defined by separate key words followed by the input values.

+

Notes:

+

*The particle type <tt>''PART''</tt> is optional in single particle simulations.

+

*The detectors estimates are integrated values over the space, angle, energy and time domains.

+

*A detector with an associated discretization in space, angle, energy and/or time turns into multiple bins. Each bin results are correspondingly integrated over the discretization domain.

+

*A single detector card may include one or several detector types. If multiple detectors are defined, the results are correspondingly divided into multiple bins.

+

Detector types:

Detector response (<tt>'''dr'''</tt>):

Line 300:

Line 710:

|-

| <tt>''MAT''</tt>

−

| : material name ~~or "<tt>VOID</tt>" if the material at the collision point is used~~

+

| : response associated material name

|}

Line 306:

Line 716:

*If the detector is assigned with multiple responses, the results are divided correspondingly into separate bins.

*The response numbers are [[ENDF reaction MT's and macroscopic reaction numbers|ENDF reaction MT's and special reaction types]].

−

*Positive response numbers are associated with microscopic cross sections ~~and the~~ result is independent of material density. Materials ~~for~~ microscopic cross sections must consist of a single nuclide.

+

**Positive response numbers:

−

*Microscopic reactions to ground and isomeric states can be calculated by adding "g" or "m" at the end of the reaction number (e.g. 102g and 102m refer to radiative capture to ground and isomeric states, respectively). This option is available only for nuclides with [[#set_bralib|branching ratios]].

+

*** They are associated with microscopic cross sections

−

*Negative response numbers are associated with macroscopic cross sections and special types~~, and the~~ result is multiplied by material density.

+

*** The detector result is independent of the material density.

−

*The response material in the <tt>'''dr'''</tt> entry must not be confused with the material in the <tt>'''dm'''</tt> entry. The former defines the material for the response function, while the latter determines the volume of integration.

+

*** Materials associated to microscopic cross sections must consist of a single nuclide.

+

***Microscopic reactions to ground and isomeric states can be calculated by adding "<tt>g</tt>" or "<tt>m</tt>" at the end of the reaction number.

+

****E.g. 102g and 102m refer to radiative capture to ground and isomeric states, respectively.

+

****This option is available only for nuclides with [[#set_bralib|branching ratios]].

+

**Negative response numbers:

+

*** They are associated with macroscopic cross sections and special types

+

*** The detector result is multiplied by material density

+

*The response material in the <tt>'''dr'''</tt> entry must not be confused with the material in the <tt>'''dm'''</tt> entry.

+

** The former defines the material for the response function, while the latter determines the volume of integration.

+

**There is a special entry for the response associated material:

+

*** "<tt>void</tt>": to allow the response not to be pre-assigned with a specific material.

+

**** When the detector scores in a collision, the cross-section is taken from the material at the collision point.

+

**** Use, e.g., to calculate integral reaction rates over regions composed of multiple materials.

+

**** It only can be used with negative response numbers.

*By default, Serpent allows a detector to have at most 10,000,000 bins.

Line 317:

Line 740:

{|

| <tt>''VOL''</tt>

−

| : volume in cm3 (3D geometry) or cross-sectional area in cm2 (2D geometry)

+

| : volume [in cm3] (3D geometry) or cross-sectional area [in cm2] (2D geometry)

|}

Notes:

−

*The results are divided by detector volume~~, which is by~~ default ~~set to~~ 1.

+

*The results are divided by detector bin-volume (default value: 1.0)

+

*In the case of surface detectors, ''VOL'' represents the surface area [in cm2] (3D geometry) or the surface length [in cm] (2D geometry).

Line 354:

Line 778:

Notes:

+

*There is a special entry for the material name:

+

**"<tt>fiss</tt>": to score only in fissile region(s)

*If multiple detector materials are defined, the results are correspondingly divided into multiple bins.

*The material entry defines the volume of integration, which must not be confused with the response material in the <tt>'''dr'''</tt> entry.

Line 369:

Line 795:

−

Cartesian mesh ~~detector~~ (<tt>'''dx'''</tt>, <tt>'''dy'''</tt> and <tt>'''dz'''</tt>):

+

Detector evenly-spaced Cartesian mesh (<tt>'''dx'''</tt>, <tt>'''dy'''</tt> and <tt>'''dz'''</tt>):

{|

| <tt>''XMIN''</tt>

−

| : minimum x-coordinate of the detector mesh

+

| : minimum x-coordinate of the detector mesh [in cm]

|-

| <tt>''XMAX''</tt>

−

| : maximum x-coordinate of the detector mesh

+

| : maximum x-coordinate of the detector mesh [in cm]

|-

| <tt>''NX''</tt>

Line 382:

Line 808:

|-

| <tt>''YMIN''</tt>

−

| : minimum y-coordinate of the detector mesh

+

| : minimum y-coordinate of the detector mesh [in cm]

|-

| <tt>''YMAX''</tt>

−

| : maximum y-coordinate of the detector mesh

+

| : maximum y-coordinate of the detector mesh [in cm]

|-

| <tt>''NY''</tt>

Line 391:

Line 817:

|-

| <tt>''ZMIN''</tt>

−

| : minimum z-coordinate of the detector mesh

+

| : minimum z-coordinate of the detector mesh [in cm]

|-

| <tt>''ZMAX''</tt>

−

| : maximum z-coordinate of the detector mesh

+

| : maximum z-coordinate of the detector mesh [in cm]

|-

| <tt>''NZ''</tt>

Line 401:

Line 827:

Notes:

−

*The mesh detectors can be used to sub-divide the results into multiple ~~spatial~~ bins. For a Cartesian mesh the division is provided with separate entries in x-, y- and z- locations.

+

*The mesh detectors can be used to sub-divide the results into multiple evenly-spaced bins.

+

*For a Cartesian mesh the division is provided with separate entries in x-, y- and z- locations (<tt>'''dx'''</tt>, <tt>'''dy'''</tt> and <tt>'''dz'''</tt>, respectively).

−

~~Curvilinear~~ mesh ~~detector~~ (<tt>'''dn'''</tt>):

+

Detector evenly-spaced curvilinear mesh (<tt>'''dn'''</tt>):

{|

| <tt>''TYPE''</tt>

−

| : ~~Type~~ of curvilinear mesh - 1 = cylindrical (dimensions ''r'', ''θ'', ''z''), 2 = spherical (dimensions ''r'', ''θ'', ''φ'')

+

| : type of curvilinear mesh - 1 = cylindrical (dimensions ''r'', ''θ'', ''z''), 2 = spherical (dimensions ''r'', ''θ'', ''φ'')

|-

| <tt>''MINn''</tt>

−

| : ~~Minimum~~ value of ~~coordinate~~ ''n'' for the mesh division.

+

| : minimum value of ''n''-coordinate for the mesh division [in cm (''r'', ''z''), in degrees (''θ'', ''φ'')].

|-

| <tt>''MAXn''</tt>

−

| : ~~Maximum~~ value of ~~coordinate~~ ''n'' for the mesh division.

+

| : maximum value of ''n''-coordinate for the mesh division [in cm (''r'', ''z''), in degrees (''θ'', ''φ'')].

|-

| <tt>''Nn''</tt>

−

| : ~~Number~~ of bins in the ''n'' coordinate direction (the division will be equal ''r'', not equal volume).

+

| : number of bins in the ''n''-coordinate direction (the radial division will be equal ''r'', not equal volume).

|}

Notes:

*All parameters must be provided, even for one- or two-dimensional curvilinear meshes.

−

*~~The results~~ are ~~not divided by cell volume~~ (~~difference to MCNP~~ mesh ~~tally~~).

+

*By default, the curvilinear mesh detectors use the global (universe 0) coordinate system for scoring.

−

*By default, the ~~curvilinear~~ mesh detectors use the global (universe 0) coordinate system for scoring. If the <tt>''TYPE''</tt> parameter is given as a negative value (e.g. -1) the lowest level coordinates are used instead.

+

**If the <tt>''TYPE''</tt> parameter is given as a negative value (e.g. -1) the lowest level coordinates are used instead.

+

Detector unevenly-spaced mesh (<tt>'''dn'''</tt>):

+

{|

+

| <tt>''TYPE''</tt>

+

| : type of curvilinear mesh - 3 = unevenly-spaced orthogonal (dimensions ''x'', ''y'', ''z''), 4 = unevenly-spaced cylindrical (dimensions ''r'', ''θ'', ''z'')

+

|-

+

| <tt>''Nn''</tt>

+

| : number of bins in the ''n''-coordinate direction

+

|-

+

| <tt>''LIMnm''</tt>

+

| : mesh ''m''-boundary in the ''n''-coordinate direction [in cm (''r'', ''z''), in degrees (''θ'', ''φ'')].

+

|}

+

Notes:

+

*All parameters must be provided, even for one- or two-dimensional meshes.

+

*By default, the unevenly-spaced mesh detectors use the global (universe 0) coordinate system for scoring.

+

**If the <tt>''TYPE''</tt> parameter is given as a negative value (e.g. -1) the lowest level coordinates are used instead.

+

−

~~Hexagonal~~ mesh ~~detector~~ (<tt>'''dh'''</tt>):

+

Detector hexagonal mesh (<tt>'''dh'''</tt>):

{|

| <tt>''TYPE''</tt>

−

| : ~~Type~~ of hexagonal mesh (2 = flat face perpendicular to x-axis, 3 = flat face perpendicular to y-axis)

+

| : type of hexagonal mesh (2 = flat face perpendicular to x-axis, 3 = flat face perpendicular to y-axis)

|-

| <tt>''X0''</tt>, <tt>''Y0''</tt>

−

| : coordinates of mesh center

+

| : coordinates of mesh center [in cm]

|-

| <tt>''PITCH''</tt>

−

| : mesh pitch

+

| : mesh pitch [in cm]

|-

−

| <tt>''N1''</tt>, <tt>''N1''</tt>

+

| <tt>''N1''</tt>, <tt>''N2''</tt>

| : mesh size

|-

| <tt>''ZMIN''</tt>

−

| : minimum z-coordinate of the detector mesh

+

| : minimum z-coordinate of the detector mesh [in cm]

|-

| <tt>''ZMAX''</tt>

−

| : maximum z-coordinate of the detector mesh

+

| : maximum z-coordinate of the detector mesh [in cm]

|-

| <tt>''NZ''</tt>

Line 454:

Line 901:

−

~~Unstructured~~ mesh ~~detector~~ (<tt>'''dumsh'''</tt>):

+

Detector unstructured mesh (<tt>'''dumsh'''</tt>):

{|

Line 469:

Line 916:

Notes:

*The polyhedral cells in [[Unstructured mesh-based geometry type|unstructured mesh based geometries]] are indexed.

−

*This detector option allows collecting results from the cells into an arbitrary number of bins. One or multiple cells can be mapped into a single bin.

+

*This detector option allows collecting results from the cells into an arbitrary number of bins.

+

*One or multiple cells can be mapped into a single bin.

Line 481:

Line 929:

Notes:

*The results are divided into multiple energy bins based on the grid structure.

−

*Energy grid structures are defined using the [[#ene (energy grid definition)|ene card]].

+

*Energy grid structures are defined using the [[#ene (energy grid definition)|ene card]].

+

**[[Pre-defined energy group structures]] can not be directly used in detectors, they have to be redefined using for example the type "<tt>4</tt>" of [[#ene|ene card]].

+

*The energy boundaries of photon photon pulse-height and photon heat analog detectors are solely defined by the associated energy grid and not limited by the unionized energy grid defining the model.

+

**That means that analog detectors might collect scores below the physics model minimum energy bound, without a cut-off, if the energy grid sets it.

Line 497:

Line 948:

−

~~Surface~~ current / flux ~~detector~~ (<tt>'''ds'''</tt>):

+

Detector current / flux surface (<tt>'''ds'''</tt>):

{|

Line 509:

Line 960:

Notes:

*With this option the detector calculates the particle flux over or current through a given surface.

−

*The surface flux mode is invoked by setting the direction parameter to -2, otherwise this parameter defines the current direction with respect to surface normal.

+

*Flux mode:

−

*Responses are not allowed with current detectors.

+

**The surface flux mode is invoked by setting the direction parameter to "<tt>-2</tt>", otherwise this parameter defines the current direction with respect to surface normal.

−

*The surface is treated separate from the geometry, and its position is always relative to the origin of the root universe. This is the case even if the surface is part of the geometry in another universe.

+

*Current mode:

+

**Responses are not allowed with current detectors, and with flux detectors, the material name at the collision point has to be specified (<tt>"void"</tt> is not allowed).

+

*The use of single-bin mesh and cell detectors is allowed to further define the surface and integration domain of the detector, from version 2.1.32 on.

+

*The surface is treated separate from the geometry, and its position is always relative to the origin of the root universe.

+

**This is the case even if the surface is part of the geometry in another universe.

*The results are integrated over the surface area (other detectors integrate over volume).

Line 518:

Line 973:

{|

−

| <tt>''COSY''</tt>

+

| <tt>''COSX''</tt>

| : component of the direction vector parallel to x-axis

|-

Line 532:

Line 987:

−

~~Super~~-imposed track-length ~~detector~~ (<tt>'''dtl'''</tt>):

+

Detector super-imposed track-length (<tt>'''dtl'''</tt>):

{|

Line 541:

Line 996:

Notes:

*This option can be used to apply the track-length estimator for calculating reaction rates inside regions defined by a single surface (sphere, cylinder, cuboid, etc.)

+

*The surface is treated separate from the geometry, and its position is always relative to the origin of the root universe.

+

**This is the case even if the surface is part of the geometry in another universe.

*The purpose of the track-length detector is to provide better statistics for special applications (activation wire measurements, etc.).

−

*~~The surface is treated separate from~~ the ~~geometry,~~ and ~~its position is always relative to the origin of the root universe. This is the case even if the~~ surface ~~is part of the geometry in another universe~~.

+

*For more information see the detailed description on [[delta- and surface-tracking]] and [[Result estimators#Implicit estimators|result estimators]].

Line 552:

Line 1,009:

|-

| <tt>''FRAC''</tt>

−

| : fraction of recorded scores and ~~ascii~~/binary option (positive value = ~~ascii~~, negative value = binary)

+

| : fraction of recorded scores and ASCII/binary option (positive value = ASCII, negative value = binary)

|}

Notes:

*This option can be used to write the scored points in a file.

−

*When used with the surface current detector this option can provide surface source distributions for other calculations.

*The fraction parameters gives the probability that the score is written in the file and it can be used to reduce the file size in long simulations.

−

*Source files can be read using the <tt>'''sf'''</tt> entry of [[#src_sf|~~source cards~~]].

+

*When used with the surface current detector this option can provide surface source distributions for other calculations.

+

*Source files can be read using the <tt>'''sf'''</tt> entry of the [[#src_sf|src card]].

−

~~Special~~ types (<tt>'''dt'''</tt>):

+

Detector special types (<tt>'''dt'''</tt>):

{|

Line 572:

Line 1,029:

|}

−

The types are:

+

The possible special types are:

−

{|

+

::{| class="wikitable" style="text-align: left;"

+

! Type

+

! Description

+

! Notes

+

|-

| -1

−

| = cumulative spectrum

+

| cumulative spectrum

+

| use with energy binning ('''de''')

|-

| -2

−

| = division by energy width

+

| division by energy width

+

| use with energy binning ('''de''')

|-

| -3

−

| = division by lethargy width

+

| division by lethargy width

+

| use with energy binning ('''de''')

|-

| -4

−

| = sum over cell or material bins

+

| sum over cell or material bins

+

| use with cell and/or material binning ('''dc''', '''dm''')

+

|-

+

| -5

+

| importance weighting

+

| -

+

|-

+

| -6

+

| sum over number of scores

+

| -

|-

| 2

−

| = multiply result with another detector defined by <tt>''PARAM''</tt>

+

| multiply result with another detector defined by <tt>''PARAM''</tt>

+

| bin-compatibility

|-

| 3

−

| = divide result with another detector defined by <tt>''PARAM''</tt>

+

| divide result with another detector defined by <tt>''PARAM''</tt>

+

| bin-compatibility

+

|-

+

| 4

+

| multiply response function by (local) temperature

+

| -

+

|-

|}

Notes:

−

*Types -1, -2 and -3 are used with energy binning.

+

*Type "<tt>3</tt> can be used to calculate flux-weighted averages (microscopic and macroscopic cross sections, etc.).

−

*Type ~~-4 can be used to calculate sum over multiple cell or material bins defined using the~~ <tt>~~'''dc'''~~</tt> ~~and <tt>'''dm'''</tt> options. By default separate bins are used for each entry.~~

+

−

*Type 3 can be used to calculate flux-weighted averages (microscopic and macroscopic cross sections, etc.).

+

−

*When the results are multiplied or divided by another detector, the number of bins must be compatible (single value or matching number of bins).

+

−

~~History~~ collection ~~option~~ (<tt>'''dhis'''</tt>):

+

Detector history collection flag (<tt>'''dhis'''</tt>):

{|

| <tt>''OPT''</tt>

−

| : option to ~~collect histories~~ (~~0 = no,~~ 1 = yes)

+

| : option to switch on (1/yes) or off (0/no) the collection of histories, batch-wise results

|}

Notes:

−

*When this option is set, the batch-wise results are ~~kept and~~ printed in the [[history output file]].

+

*When this option is set, the batch-wise results are printed in the history output file, <tt>[input]_stats.m</tt>.

+

*The statistical tests are described in a related report<ref name="stat_tests">Kaltiaisenaho, T. ''"Statistical tests and the underestimation of variance in Serpent 2."'' VTT-R-00371-14, VTT Technical Research Centre of Finland, [https://serpent.vtt.fi/serpent/download/VTT-R-00371-14.pdf 2014]</ref>.

*''Note to developers: statistical tests should be documented''

−

Detector flagging (<tt>'''dfl'''</tt>):

+

Detector score flagging (<tt>'''dfl'''</tt>):

{|

Line 620:

Line 1,099:

| <tt>''OPT''</tt>

| : flagging option (0 = reset if scored, 1 = set if scored, -2/2 score if set -3/3 score if not set)

+

|}

+

The possible flagging options are:

+

::{| class="wikitable" style="text-align: left;"

+

! Flag

+

! Description

+

! Notes

+

|-

+

| <tt>0</tt>

+

| reset if scored

+

| -

+

|-

+

| <tt>1</tt>

+

| set if scored

+

| -

+

|-

+

| <tt>-2/2</tt>

+

| score if set

+

| 2 (apply OR-type logic), -2 (apply AND-type logic)

+

|-

+

| <tt>-3/3</tt>

+

| score if not set

+

| 3 (apply OR-type logic), -3 (apply AND-type logic)

+

|-

|}

Notes:

*Detector flagging allows limiting detector scores to histories which have already contributed to another score.

−

*~~The first two options reset or set the flag if the detector is scored, respectively. The remaining options test if the flag is set and score the detector accordingly. Positive values apply~~ OR-type logic (detector is scored if any of the associated flags is set/unset~~) and negative values~~ AND-type logic (detector is scored if all the associated flags are set/unset).

+

*Scoring logic:

+

** OR-type logic: detector is scored if any of the associated flags is set/unset

+

** AND-type logic: detector is scored if all the associated flags are set/unset

−

~~Activation detector~~ (<tt>'''da'''</tt>):

+

Detector activation (<tt>'''da'''</tt>):

{|

Line 634:

Line 1,140:

|-

| <tt>''FLX''</tt>

−

| : flux applied to activation

+

| : flux applied to activation [in 1/cm2s]

|}

Notes:

−

*Activation detector allows performing activation calculation for materials that are not part of the geometry. The flux spectrum applied to neutron irradiation is taken from the detector scores. The absolute flux level can be set using the <tt>''FLX''</tt> parameter. ~~If this parameter~~ is ~~set to~~ -1, ~~also~~ the flux magnitude is taken from the detector scores.

+

*Activation detector allows performing activation calculation for materials that are not part of the geometry.

−

*Requires neutron transport simulation and burnup mode. The material ~~provided with the entry~~ must be burnable, and cannot part of the actual geometry. ~~Volume~~ of the material must be defined using the <tt>'''dv'''</tt> parameter.

+

*Flux applied to activation:

+

**The flux spectrum applied to neutron irradiation is taken from the detector scores.

+

**The absolute flux level can be set using the <tt>''FLX''</tt> parameter.

+

***There is a special entry for the <tt>''FLX''</tt> parameter:

+

**** "<tt>-1</tt>": in this case, the flux magnitude is also taken from the detector scores.

+

*Requires neutron transport simulation and burnup mode.

+

*The detector associated material must be burnable, and cannot part of the actual geometry.

+

*The volume of the material, aka detector, must be defined using the <tt>'''dv'''</tt> parameter.

*Since the activated material is not part of the physical geometry, this option should be applied only to small samples and other activation calculations in which the isotopic changes do not significantly affect the neutronics.

−

Functional Expansion Tally ~~detector~~ (<tt>'''dfet'''</tt>):

+

Detector Functional Expansion Tally, FET (<tt>'''dfet'''</tt>):

{|

Line 652:

Line 1,166:

|}

−

{| class="wikitable" style="text-align: left;"

+

::{| class="wikitable" style="text-align: left;"

! Geometry

! <tt>PARAMS</tt>

Line 661:

Line 1,175:

|-

| rowspan="1"|Cartesian

−

| rowspan="1"|<tt>''XMIN'' ''XMAX'' ''XORDER'' ''YMIN'' ''YMAX'' ''YORDER'' ''ZMIN'' '' ZMAX'' ''ZORDER''</tt>

+

| rowspan="1"|<tt>''XMIN'' ''XMAX'' ''XORDER'' ''YMIN'' ''YMAX'' ''YORDER'' ''ZMIN'' ''ZMAX'' ''ZORDER''</tt>

| <tt>1</tt>

| Legendre only

| <math>\psi(\xi)_n = P_i(\xi_x) P_j(\xi_y) P_k(\xi_z) </math>

| <math>n = k + J * \left( i * I + j\right)</math>

+

|-

+

| rowspan="1"|Cylindrical

+

| rowspan="1"|<tt> ''RMAX'' ''RORDER'' ''HMIN'' ''HMAX'' ''HORDER'' ''HORIENTATION''</tt>

+

| <tt>2</tt>

+

| ..

+

| ..

+

| ..

|}

Notes:

−

*<tt>-1</tt> can be supplied as an <tt>''ORDER''</tt> <tt>PARAM</tt> to use the built-in default values

+

*"<tt>-1</tt>" can be supplied as an <tt>''ORDER''</tt> <tt>PARAM</tt> to use the built-in default values

*It is not recommended to configure a single FET detector to span multiple different material regions—use individual detectors for each region instead

*Specifics of this implementation:

Line 678:

Line 1,199:

***The generated FET coefficients <math>a_n</math> already have all contributions from the orthonormalization constant pre-included, i.e. <math>c_n</math> from <math>\frac{1}{c_n} = \lVert \psi_n \rVert^2 = \int_\Gamma \psi_n^2 \omega_n </math>

***Thus, an FET can be simply reconstructed/sampled from the standard functional series as: <math>F(\xi) = \sum a_n \psi_n(\xi) \omega_n(\xi)</math>

+

*From version 2.2.0 and on, FET-based detectors follow the standard normalization set in the calculation. The volume standards for detectors are set as default value for FET-based detectors, meaning detectors are not divided by the physical volume (allowing the use of volume detector '''dv''').

+

*In version 2.2.0, the relative error evaluation associated with FET-based detectors has been revisited.

+

Detector pulse-height energy broadening (<tt>'''dphb'''</tt>):

+

{|

+

| <tt>''PHB''</tt>

+

| : user-defined (Gaussian) energy broadening for pulse-height detector function name

+

|}

+

Notes:

+

* User-defined Gaussian energy broadening functions for pulse height detector are defined using the [[#phb|phb card]].

+

Detector spatial integration domain and binning based on a generic data mesh (<tt>'''dmesh'''</tt>):

+

{|

+

| <tt>''MESH''</tt>

+

| : name of the [[#datamesh|datamesh]] to use for defining the spatial integration domain and binning for the detector scores

+

|}

+

Notes:

+

* Output mesh index will be flattened (one dimensional).

=== div (divisor definition) ===

−

'''div''' ''MAT'' [ '''sep''' ''LVL'' ]

+

'''div''' ''MAT'' [ [[#div_sep|'''sep''']] ''LVL'' ]

−

[ '''subx''' ''NX'' ''XMIN'' ''XMAX'' ]

+

[ [[#div_subx1|'''subx''']] ''NX'' ''XMIN'' ''XMAX'' ]

−

[ '''suby''' ''NY'' ''YMIN'' ''YMAX'' ]

+

[ [[#div_subx2|'''subx''']] ''NX'' ''X1'' ''X2'' ... ''XN+1'' ]

−

[ '''subz''' ''NZ'' ''ZMIN'' ''ZMAX'' ]

+

[ [[#div_suby1|'''suby''']] ''NY'' ''YMIN'' ''YMAX'' ]

−

[ '''subr''' ''NR'' ''RMIN'' ''RMAX'' ]

+

[ [[#div_suby2|'''suby''']] ''NY'' ''Y1'' ''Y2'' ... ''YN+1'' ]

−

[ '''subs''' ''NS'' ''S0'' ]

+

[ [[#div_subz1|'''subz''']] ''NZ'' ''ZMIN'' ''ZMAX'' ]

−

Divides a material into a number of sub-zones. ~~Input values~~:

+

[ [[#div_subz2|'''subz''']] ''NZ'' ''Z1'' ''Z2'' ... ''ZN+1'' ]

+

[ [[#div_subr1|'''subr''']] ''NR'' ''RMIN'' ''RMAX'' ]

+

[ [[#div_subr2|'''subr''']] ''NR'' ''R1'' ''R2'' ... ''RN+1'' ]

+

[ [[#div_subs1|'''subs''']] ''NS'' ''S0'' ]

+

[ [[#div_subs2|'''subs''']] ''NS'' ''S1'' ''S2'' ... ''SN+1'' ]

+

[ [[#div_peb|'''peb''']] ''PBED'' ''NUNI'' [ ''UNI1'' ... ''UNIN'' ] ]

+

[ [[#div_lims|'''lims''']] ''FLAG'' ]

+

Divides a material into a number of sub-zones. The first parameter:

{|

| <tt>''MAT''</tt>

| : name of the divided material

−

|-

+

|}

+

The remaining parameters are defined by separate key words followed by the input values.

+

Notes:

+

*A single div card may include one or several sub-divisions.

+

*As general rule:

+

** if the number of zones associated with a sub-division is positive, the sub-division is equal volume (see below)

+

** if the number of zones associated with a sub-division is negative, the subdivision is user-defined volume (see below)

+

*If a material is not divided, all occurrences of it are treated as a single depletion zone (except for depleted materials defined in pin structures: pin-type division).

+

*The use of automated instead of manual depletion zone division saves memory, which may become significant in very large burnup calculation problems (see [[#set opti|set opti]]).

+

*The volumes of the divided materials must be set manually (see [[#set mvol|set mvol]] option) or automatically, via the Monte Carlo checker-routine (see [[#set mcvol|set mcvol]] option or [[Installing and running Serpent#Running Serpent|''-checkvolumes'']] command line option).

+

**For a more detailed description, check [[Defining material volumes|Defining material volumes]]).

+

*For more information, see detailed description on [[automated depletion zone division]].

+

Sub-division types:

+

Sub-division geometry level (<tt>'''sep'''</tt>):

+

{|

| <tt>''LVL''</tt>

−

| : geometry level at which the ~~cell~~-wise division takes place (0 = no division, 1 = last level, 2 = 2nd last level, etc.)

+

| : geometry level at which the material-wise division takes place (0 = no division, 1 = last level, 2 = 2nd last level, etc.)

|-

+

|}

+

Notes:

+

*The sub-division criterion is the geometry level.

+

*The level number is counted backwards from the last one, i.e. level "<tt>1</tt>" is the last level.

+

*Use examples:

+

**to sub-divide the fuel in large LWR core into separate depletion zones on assembly-, instead of pin-basis.

+

**to sub-divide HTGR fuel kernels into depletion zones on compact- or pebble-basis.

+

Sub-division Cartesian mesh, equal volume (<tt>'''subx'''</tt>, <tt>'''suby'''</tt> and <tt>'''subz'''</tt>):

+

{|

| <tt>''NX''</tt>

−

| : number of x-zones

+

| : number of x-zones (positive value)

|-

| <tt>''XMIN''</tt>

−

| : minimum x-coordinate (cm)

+

| : minimum x-coordinate [in cm]

|-

| <tt>''XMAX''</tt>

−

| : maximum x-coordinate (cm)

+

| : maximum x-coordinate [in cm]

|-

| <tt>''NY''</tt>

−

| : number of y-zones

+

| : number of y-zones (positive value)

|-

| <tt>''YMIN''</tt>

−

| : minimum y-coordinate (cm)

+

| : minimum y-coordinate [in cm]

|-

| <tt>''YMAX''</tt>

−

| : maximum y-coordinate (cm)

+

| : maximum y-coordinate [in cm]

|-

| <tt>''NZ''</tt>

−

| : number of z-zones

+

| : number of z-zones (positive value)

|-

| <tt>''ZMIN''</tt>

−

| : minimum z-coordinate (cm)

+

| : minimum z-coordinate [in cm]

|-

| <tt>''ZMAX''</tt>

−

| : maximum z-coordinate (cm)

+

| : maximum z-coordinate [in cm]

|-

+

|}

+

Notes:

+

* An equal volume sub-division is performed in the given dimension.

+

* The value of the parameter <tt>''Nn''</tt> which defines the number of zones in the given dimension must be positive.

+

* For a Cartesian mesh sub-division, a separate entry in x-, y-, z- directions is provided (<tt>'''subx'''</tt>, <tt>'''suby'''</tt> and <tt>'''subz'''</tt>, respectively).

+

Sub-division Cartesian mesh, user-defined volume (<tt>'''subx'''</tt>, <tt>'''suby'''</tt> and <tt>'''subz'''</tt>):

+

{|

+

| <tt>''NX''</tt>

+

| : number of x-zones (negative value)

+

|-

+

| <tt>''Xn''</tt>

+

| : x-coordinate boundaries [in cm]

+

|-

+

| <tt>''NY''</tt>

+

| : number of y-zones (negative value)

+

|-

+

| <tt>''Yn''</tt>

+

| : y-coordinate boundaries [in cm]

+

|-

+

| <tt>''NZ''</tt>

+

| : number of z-zones (negative value)

+

|-

+

| <tt>''Zn''</tt>

+

| : z-coordinate boundaries [in cm]

+

|-

+

|}

+

Notes:

+

* An user-defined volume sub-division is performed in the given dimension.

+

* The value of the parameter <tt>''Nn''</tt> which defines the number of zones in the given dimension must be negative.

+

* For a Cartesian mesh sub-division, a separate entry in x-, y-, z- directions is provided (<tt>'''subx'''</tt>, <tt>'''suby'''</tt> and <tt>'''subz'''</tt>, respectively).

+

Sub-division cylindrical annular mesh, equal volume (<tt>'''subr'''</tt>):

+

{|

| <tt>''NR''</tt>

−

| : number of radial zones

+

| : number of radial-zones (positive value)

|-

| <tt>''RMIN''</tt>

−

| : minimum radial coordinate (cm)

+

| : minimum radial-coordinate [in cm]

|-

| <tt>''RMAX''</tt>

−

| : maximum radial coordinate (cm)

+

| : maximum radial-coordinate [in cm]

|-

+

|}

+

Notes:

+

* An equal volume radial sub-division is performed (annular-type sub-division)

+

* The value of the parameter <tt>''NR''</tt> which defines the number of zones in the given dimension must be positive.

+

Sub-division cylindrical annular mesh, user-defined volume (<tt>'''subr'''</tt>):

+

{|

+

| <tt>''NR''</tt>

+

| : number of radial-zones (negative value)

+

|-

+

| <tt>''Rn''</tt>

+

| : radial-coordinate boundaries [in cm]

+

|-

+

|}

+

Notes:

+

* An user-defined volume radial sub-division is performed (annular-type sub-division)

+

* The value of the parameter <tt>''NR''</tt> which defines the number of zones in the given dimension must be negative.

+

Sub-division cylindrical sector mesh, equal volume (<tt>'''subs'''</tt>):

+

{|

| <tt>''NS''</tt>

−

| : number of angular ~~sectors~~

+

| : number of angular-zones (negative value)

|-

| <tt>''S0''</tt>

−

| : zero position of angular division (degrees)

+

| : zero position of angular division [in degrees]

+

|-

|}

Notes:

+

* An equal volume angular sub-division is performed (sector-type sub-division)

+

* The value of the parameter <tt>''NS''</tt> which defines the number of zones in the angular dimension must be positive.

−

*The automated divisor feature can be used to sub-divide burnable materials into depletion zones, but the use is not limited to burnup mode.

−

*The spatial sub-division is based on either Cartesian or cylindrical mesh.

−

*Volumes of the divided materials must be set manually (see detailed description on [[Defining material volumes|the definition of material volumes]]).

−

*Using automated instead of manual depletion zone division saves memory, which may become significant in very large burnup calculation problems (see detailed description on [[memory usage#automated depletion zone division|memory usage]]).

−

*For more information see detailed description on [[automated depletion zone division]].

−

*The usage of <tt>''LVL''</tt> is explained on page [[automated depletion zone division]].

−

~~=== ene~~ (~~energy grid definition~~) ~~===~~

+

Sub-division cylindrical sector mesh, user-defined volume (<tt>'''subs'''</tt>):

−

''~~'ene''' ''NAME'' '''1''' ''E~~0'' ''E1'' ~~...~~

+

{|

+

| <tt>''NS''</tt>

+

| : number of angular-zones

+

|-

+

| <tt>''Sn''</tt>

+

| : angular-sector boundaries [in degrees]

+

|-

+

|}

−

~~'''ene''' ''NAME'' '''2'''~~ ''N~~'' ''E~~~~min~~'' ''E~~max~~''

+

Notes:

+

* An user-defined volume angular sub-division is performed (sector-type sub-division)

+

* The value of the parameter <tt>''NS''</tt> which defines the number of zones in the angular dimension must be negative.

+

* The manually-spaced angular-sector boundaries <tt>''Sn''</tt> must cover the full/360 degrees angular space.

−

~~'''ene''' ''NAME'' '''3''' ''N'' ''Emin'' ''Emax''~~

−

'''~~ene~~''' ''~~NAME~~'' '''4''' ''~~GRID~~''

+

Sub-division pebble-bed structure (<tt>'''peb'''</tt>):

+

{|

+

| <tt>''PBED''</tt>

+

| : stochastic particle / pebble-bed structure

+

|-

+

| <tt>''NUNI''</tt>

+

| : number of universes to link related to the <tt>''PBED''</tt> structure (special case: 0 = link to all)

+

|-

+

| <tt>''UNIN''</tt>

+

|: list of universes to link (non-zero number of universes)

+

|-

+

|}

+

Notes:

+

*The pebble bed-based sub-division divides each item in a pebble bed universe as its own item.

+

*It features a speed-up on the depletion zone division indexing process with large number of pebble bed structures.

+

Sub-division limit enforcement (<tt>'''lims'''</tt>):

+

{|

+

| <tt>''FLAG''</tt>

+

| : flag for mapping regions outside (material) limits to divide material: on (1/yes) or off (0/no). The default option is "<tt>off</tt>"

+

|-

+

|}

+

=== dtrans (detector mesh transformation) ===

+

Defines detector mesh transformations. Shortcut for "trans d".

+

Notes:

+

*The parameters associated with the transformation follow the standard transformation cards syntax without '''trans''' <tt>''TYPE''</tt> identifier.

+

*See [[#trans (transformations)|transformations]].

+

=== ene (energy grid definition) ===

+

'''ene''' ''NAME'' ''TYPE'' [ ... ]

Defines an energy grid structure. Input values:

Line 763:

Line 1,456:

|<tt>''NAME''</tt>

|: energy grid name

+

|-

+

|<tt>''TYPE''</tt>

+

|: energy grid type

+

|-

+

|}

+

The remaining parameters are type-dependent.

+

The available energy grid structure types are:

+

::{| class="wikitable" style="text-align: left;"

+

! Type

+

! Description

+

|-

+

| [[#ene_1|<tt>1</tt>]]

+

| arbitrary defined grid

+

|-

+

| [[#ene_2|<tt>2</tt>]]

+

| equal energy-width bins

+

|-

+

| [[#ene_3|<tt>3</tt>]]

+

| equal lethargy-width bins

+

|-

+

| [[#ene_4|<tt>4</tt>]]

+

| [[pre-defined energy group structures|pre-defined energy group structure]]

+

|-

+

|}

+

The syntax of the available types is as follows:

+

'''ene''' ''NAME'' '''1''' ''E0'' ''E1'' ...

+

{|

|-

|<tt>''Ei''</tt>

−

|: bin boundaries ~~(type 1)~~

+

|: bin boundaries [in MeV]

+

|-

+

|}

+

'''ene''' ''NAME'' '''2''' ''N'' ''Emin'' ''Emax''

+

{|

|-

|<tt>''N''</tt>

−

|: number of equi-width bins ~~(types 2 ad 3)~~

+

|: number of equi-width bins

|-

|<tt>''Emin''</tt>

−

|: minimum energy ~~(types 2 and 3)~~

+

|: minimum energy [in MeV]

|-

|<tt>''Emax''</tt>

−

|: maximum energy ~~(types 2 and~~ 3)

+

|: maximum energy [in MeV]

+

|-

+

|}

+

'''ene''' ''NAME'' '''3''' ''N'' ''Emin'' ''Emax''

+

{|

+

|-

+

|<tt>''N''</tt>

+

|: number of equi-width bins

+

|-

+

|<tt>''Emin''</tt>

+

|: minimum energy [in MeV]

+

|-

+

|<tt>''Emax''</tt>

+

|: maximum energy [in MeV]

+

|-

+

|}

+

'''ene''' ''NAME'' '''4''' ''GRID''

+

{|

|-

|<tt>''GRID''</tt>

−

|: name of the pre-defined ~~grid (type 4)~~

+

|: name of the [[pre-defined energy group structures|pre-defined energy group structure]]

|}

Notes:

−

+

*Energy grid structures are used for several purposes, e.g. with detectors ('''de''' entry in the [[#det_de|det card]]).

−

*The first input parameter gives the type (1 = arbitrarily defined, 2 = equal energy-width bins, 3 = equal lethargy-width bins, 4 = pre-defined energy group structure).

+

−

*Energy grid structures are used for several purposes, ~~most commonly~~ with [[#det_de|~~detectors]].~~

+

−

*See separate description of [[pre-defined energy group structures]].

+

=== ftrans (fill transformation) ===

−

See [[#trans (transformations)|transformations]].

+

Defines fill transformations. Shortcut for "<tt>trans f</tt>".

+

Notes:

+

*The parameters associated with the transformation follow the standard transformation cards syntax without '''trans''' <tt>''TYPE''</tt> identifier.

+

*See [[#trans (transformations)|transformations]].

=== fun (function definition) ===

Line 801:

Line 1,554:

|-

|<tt>''TYPE''</tt>

−

|: function type ~~(currently only supported type is 1 = point-wise tabular data)~~

+

|: function type

|}

−

The ~~syntax for~~ type ~~1 is:~~

+

The remaining input values are type-dependent.

−

'''fun''' ''NAME'' '''1''' ''INTT'' ''X1'' ''F1'' ''X2'' ''F2'' ...

+

Notes:

+

* The defined function is linked to detector response using [[ENDF reaction MT's and macroscopic reaction numbers|MT -100 ]] (syntax: dr -100 ''NAME'').

+

* The defined function currently is only supported as a flux-based function, aka, flux multiplier.

+

The available function types are:

+

::{| class="wikitable" style="text-align: left;"

+

! Type

+

! Description

+

|-

+

| [[#fun_1|<tt>1</tt>]]

+

| point-wise tabular data

+

|-

+

|}

+

The syntax for the available types is as follows:

+

'''fun''' ''NAME'' '''1''' ''INTT'' ''X1'' ''F1'' ''X2'' ''F2'' ...

−

~~where:~~

{|

|<tt>''INTT''</tt>

|: is the interpolation type (1 = histogram, 2 = lin-lin, 3 = lin-log, 4 = log-lin, 5 = log-log)

|-

−

|<tt>''X1'' ''F1'' ~~...~~</tt>

+

|<tt>''Xi'', ''Fi''</tt>

|: are the tabulated variable-value pairs

+

|}

+

=== hisv (history variation matrix definition) ===

+

'''hisv''' [ ''BU1'' ''NBR1'' ''BR1,1'' ''BR1,2'' ... ''BR1,NBR1'' ]

+

[ ''BU2'' ''NBR2'' ''BR2,1'' ''BR2,2'' ... ''BR2,NBR2'' ]

+

...

+

Defines the history variation matrix for the automated burnup sequence. Input values:

+

{|

+

| <tt>''BUn''</tt>

+

| : burnup steps at which the branches are invoked (positive value = burnup [in MWd/kg], negative value = time [in d])

+

|-

+

| <tt>''NBRn''</tt>

+

| : number branches in the ''n''-th burnup step

+

|-

+

| <tt>''BRn,i''</tt>

+

| : name of the ''i''-th branch in the ''n''-th burnup step

|}

Notes:

−

* The defined ~~function~~ is ~~linked to detector response using~~ [[~~ENDF reaction MT's and macroscopic reaction numbers~~|~~response number~~]] ~~-100 (syntax: dr -100 ''NAME'')~~.

+

*The automated burnup sequence defined by the hisv card follows the same principle as the [[#coef|coef]] input card.

+

*The hisv card performs multiple depletions within a single depletion calculation following the historical variation sequence.

+

**It performs a restart at each of the listed burnup points, where it applies the variations defined in the listed branches for the given burnup point.

+

*The hisv card is used together with the [[#branch|branch]] card.

=== ifc (interface file) ===

−

'''ifc''' ''FILE''

+

'''ifc''' ''FILE'' [ [[#ifc_setinmat|'''setinmat''']] ''NMAT'' ''MAT1'' ''MAT2'' ... ''MATNMAT'' ]

+

[ [[#ifc_setoutmat|'''setoutmat''']] ''NMAT'' ''MAT1'' ''MAT2'' ... ''MATNMAT'' ]

−

Links a [[Multi-physics interface|multi-physics interface]] file to be used with the current input. ~~Input values~~:

+

Links a [[Multi-physics interface|multi-physics interface]] file to be used with the current input. The first parameter:

{|

|<tt>''FILE''</tt>

|: path to the multi-physics interface file

+

|}

+

The remaining parameters are defined by separate key words followed by the input values, being optional.

+

Notes:

+

*See also [[Coupled multi-physics calculations]].

+

Optional entries:

+

Interface input materials (<tt>'''setinmat'''</tt>):

+

{|

+

| <tt>''NMAT''</tt>

+

| : number of input materials to link to the interface

+

|-

+

| <tt>''MATn''</tt>

+

| : name of the ''n''-th input material linked to the interface

+

|}

+

Notes:

+

*It adds the possibility to link multiple input materials to the same interface, i.e. the same interface gives temperatures and densities (density factors) for multiple materials.

+

*If multiple input materials are linked to the interface using the option, the densities in the interface file must be given as density factors, i.e. relative to the material card density (values between 0 and 1).

+

*If the interface is not updated, the entry is not eligible.

+

*If the regular mesh-based interface is used and power is tallied in pin-type objects, the entry is not eligible.

+

*The option '''<tt>setinmat</tt>''' is referred as '''<tt>setmat</tt>''' up to version 2.1.31.

+

Interface output materials (<tt>'''setoutmat'''</tt>):

+

{|

+

| <tt>''NMAT''</tt>

+

| : number of output materials to link to the interface

+

|-

+

| <tt>''MATn''</tt>

+

| : name of the ''n''-th output material linked to the interface

|}

Notes:

−

* ~~See also [[Coupled multi~~-~~physics calculations]]~~.

+

*It adds the possibility to link multiple output materials to the same interface, i.e. the same interface gives temperatures and densities (density factors) for multiple materials.

+

*If multiple input materials are linked to the interface using the option, the densities in the interface file must be given as density factors, i.e. relative to the material card density (values between 0 and 1).

+

* If the interface is not updated, the entry is not eligible.

+

*If the regular mesh-based interface is used and if power is not tallied on the same mesh, the entry is not eligible.

=== include (read another input file) ===

Line 847:

Line 1,676:

*The include card can be used to simplify the structure of complicated inputs.

−

*The input parser starts reading and processing the new file from the point where the input card is placed. Processing of the original file continues after the new file is completed.

+

*The input parser starts reading and processing the new file from the point where the input card is placed.

−

*The included file must contain complete input cards ~~and~~ and options, it cannot be used to read the values of another card.

+

**Processing of the original file continues after the new file is completed.

+

*The included file must contain complete input cards and options, it cannot be used to read the values of another card.

+

*Nested included file paths must refer to the original base input file or current working directory.

=== lat (regular lattice definition) ===

−

~~See also Section 3.6 of [http://montecarlo.vtt.fi/download/Serpent_manual.pdf Serpent 1 User Manual].~~

+

'''lat''' ''UNI'' ''TYPE'' [ ... ]

−

+

Defines a regular lattice universe. Input values:

−

~~Notes:~~

+

−

*With 2D lattices the numbering of lattice positions is such that the bottommost row is given first from left to right and the topmost row is given last from left to right.

+

−

+

−

'''lat''' ''UNI ~~TYPE X0 Y0 NX NY PITCH~~'' ''~~UNI1 UNI2~~ ...''

+

−

+

−

Defines a ~~finite two-dimensional lattice in xy-plane with square or X- or Y-type hexagonal elements. The~~ lattice ~~is infinite in z-direction~~. Input values:

+

{|

Line 868:

Line 1,693:

| : lattice type

|-

+

|}

+

The remaining input values are case/type-dependent.

+

Notes:

+

* For more information, see also Section 3.6 of [http://montecarlo.vtt.fi/download/Serpent_manual.pdf Serpent 1 User Manual].

+

The available lattice definitions and types (condensed in five cases) are:

+

::{| class="wikitable" style="text-align: left;

+

! Case

+

! xy-plane description

+

! z-direction description

+

! Types

+

|-

+

| [[#lattice_I|<tt>I</tt>]]

+

| finite 2D lattice with square, hexagonal or triangular elements

+

| infinite z-direction

+

| 1 = square, 2 = X-type hexagonal, 3 = Y-type hexagonal, 14 = X-type triangular

+

|-

+

| [[#lattice_II|<tt>II</tt>]]

+

| infinite 2D lattice with square or hexagonal elements

+

| infinite z-direction

+

| 6 = square, 7 = X-type hexagonal, 8 = Y-type hexagonal

+

|-

+

| [[#lattice_III|<tt>III</tt>]]

+

| finite 2D lattice circular cluster array

+

| infinite z-direction

+

| 4 = circular cluster array

+

|-

+

| [[#lattice_IV|<tt>IV</tt>]]

+

| infinite xy-plane

+

| finite 1D lattice with vertical stack

+

| 9 = vertical stack

+

|-

+

| [[#lattice_V|<tt>V</tt>]]

+

| finite 3D lattice with square or hexagonal elements

+

| finite 3D lattice

+

| 11 = cuboid, 12 = X-type hexagonal prism, 13 = Y-type hexagonal prism

+

|-

+

|}

+

The syntax of the available cases is as follows:

+

Case I:

+

finite 2D lattice in xy-plane with square, X- or Y-type hexagonal, or X-type triangular elements, and infinite in z-direction.

+

'''lat''' ''UNI TYPE X0 Y0 NX NY PITCH'' ''UNI1 UNI2 ...''

+

{|

| <tt>''X0''</tt>

−

| : x-coordinate of the lattice origin

+

| : x-coordinate of the lattice origin (origin is in the center of the lattice) [in cm].

|-

| <tt>''Y0''</tt>

−

| : y-coordinate of the lattice origin

+

| : y-coordinate of the lattice origin (origin is in the center of the lattice) [in cm].

|-

| <tt>''NX''</tt>

Line 881:

Line 1,755:

|-

| <tt>''PITCH''</tt>

−

| : lattice pitch

+

| : lattice pitch [in cm]

|-

| <tt>''UNIn''</tt>

Line 887:

Line 1,761:

|}

−

Possible lattice ~~types~~ are:

+

Possible lattice definitions are:

−

{| class="wikitable" style="text-align: left;"

+

::{| class="wikitable" style="text-align: left;"

! Type

! Description

Line 900:

Line 1,774:

| 3

| Y-type hexagonal lattice

+

|-

+

| 14

+

| X-type triangular lattice

|}

+

[[File:Rect lattice index.png|frame|Lattice type 1 indexing example for NX = NY = 3.]]

+

[[File:Hex lattice x index.png|frame|Lattice type 2 indexing example for NX = NY = 3.]]

+

[[File:Hex lattice y index.png|frame|Lattice type 3 indexing example for NX = NY = 3.]]

Notes:

−

*Number of universes ~~in list of~~ universes must be NX times NY.

+

*Number of listed universes universes must be ''NX × NY''.

−

*For square lattices the x coordinate increases from left to right and the y coordinate increases from top to bottom, so the first NX values in the list of universes create the bottommost (minimum y) row from minimum x to maximum x and the last NX values in the list of universes create the topmost (maximum y) values.

+

*For square lattices the x-coordinate increases from left to right and the y-coordinate increases from top to bottom, so the first ''NX'' values in the list of universes create the bottommost (minimum y) row from minimum x to maximum x and the last ''NX'' values in the list of universes create the topmost (maximum y) values. Example of the indexing is provided in the attached figure.

−

*The line breaks usually ~~given~~ in the list of universes are ~~just for visual~~ help of the user.

+

*The line breaks usually present in the list of universes are only used to help visualizing the universe order for the user. Serpent ignores them when processing the list of universes.

−

*The input of X and Y type hexagonal lattices is similar to each other, only the directions of the x and y axis change. The axis directions ~~are easily~~ checked by using the [[#plot (geometry plot definition)|geometry plotter]].

+

*The input of X- and Y-type hexagonal lattices is similar to each other, only the directions of the x- and y-axis change. The axis directions can be checked by using the [[#plot (geometry plot definition)|geometry plotter]]. Examples of the indexing are provided in the attached figures.

−

~~'''lat''' ''UNI TYPE X0 Y0 PITCH UNI1''~~

−

~~Defines an~~ infinite ~~two-dimensional~~ lattice in xy-plane with infinitely repeating square or X- or Y-type hexagonal element~~. The lattice is~~ infinite in z-direction.

+

Case II:

+

infinite 2D lattice in xy-plane with infinitely repeating square or X- or Y-type hexagonal element, and infinite in z-direction.

+

'''lat''' ''UNI TYPE X0 Y0 PITCH UNI1''

{|

−

~~| <tt>''UNI''</tt>~~

−

~~| : universe name of the lattice~~

−

|-

−

~~| <tt>''TYPE''</tt>~~

−

~~| : lattice type~~

−

|-

| <tt>''X0''</tt>

−

| : x-coordinate of the lattice origin

+

| : x-coordinate of the lattice origin [in cm]

|-

| <tt>''Y0''</tt>

−

| : y-coordinate of the lattice origin

+

| : y-coordinate of the lattice origin [in cm]

|-

| <tt>''PITCH''</tt>

−

| : lattice pitch

+

| : lattice pitch [in cm]

|-

| <tt>''UNI1''</tt>

Line 933:

Line 1,810:

Possible lattice types are:

−

{| class="wikitable" style="text-align: left;"

+

::{| class="wikitable" style="text-align: left;"

! Type

! Description

Line 948:

Line 1,825:

Notes:

−

*The order of X- and Y-type hexagonal lattice type numbers is reversed when ~~comparing~~ with finite hexagonal lattices.

+

*The order of X- and Y-type hexagonal lattice type numbers is reversed when compared with finite hexagonal lattices.

+

Case III:

+

finite 2Dl circular cluster array lattice in xy-plane and infinite in z-direction.

'''lat''' ''UNI TYPE X0 Y0 NR'' ''NS,1 RADIUS1 THETA1 UNI1,1 UNI2,1 ... NS,2 RADIUS2 THETA2 UNI1,2 UNI2,2 ... ...''

−

~~Defines a finite two-dimensional circular cluster array lattice in xy-plane. The lattice is infinite in z-direction.~~

{|

−

~~| <tt>''UNI''</tt>~~

−

~~| : universe name of the lattice~~

−

|-

−

~~| <tt>''TYPE''</tt>~~

−

~~| : lattice type~~

−

|-

| <tt>''X0''</tt>

−

| : x-coordinate of the lattice origin

+

| : x-coordinate of the lattice origin [in cm]

|-

| <tt>''Y0''</tt>

−

| : y-coordinate of the lattice origin

+

| : y-coordinate of the lattice origin [in cm]

|-

| <tt>''NR''</tt>

Line 971:

Line 1,844:

|-

| <tt>''NS,R''</tt>

−

| : number of sectors in R:th ring

+

| : number of sectors in ''R''-th ring

|-

| <tt>''RADIUSR''</tt>

−

| : central radius of R:th ring

+

| : central radius of ''R''-th ring [in cm]

|-

| <tt>''THETAR''</tt>

−

| : angle of rotation of R:th ring in degrees

+

| : angle of rotation of ''R''-th ring [in degrees]

|-

| <tt>''UNIN,R''</tt>

−

| : list of universes filling the sector positions in R:th ring

+

| : list of universes filling the sector positions in ''R''-th ring

|}

−

Possible lattice ~~types are~~:

+

Possible lattice type is:

−

{| class="wikitable" style="text-align: left;"

+

::{| class="wikitable" style="text-align: left;"

! Type

! Description

Line 995:

Line 1,868:

*The circular cluster array can be used to define fuel assemblies used for example in AGR, CANDU, MAGNOX and RBMK reactors. It can also be used to define fuel rod layout used for example in TRIGA reactors.

−

~~'''lat''' ''UNI TYPE X0 Y0 NL Z1 UNI1 Z2 UNI2 ...''~~

−

~~Defines a~~ finite ~~one-dimensional~~ vertical stack in z-direction. ~~The stack is infinite in xy-plane~~.

+

Case IV:

+

infinite lattice in xy-plane, and finite 1D vertical stack in z-direction

+

'''lat''' ''UNI TYPE X0 Y0 NL Z1 UNI1 Z2 UNI2 ...''

{|

−

~~| <tt>''UNI''</tt>~~

−

~~| : universe name of the lattice~~

−

|-

−

~~| <tt>''TYPE''</tt>~~

−

~~| : lattice type~~

−

|-

| <tt>''X0''</tt>

−

| : x-coordinate of the lattice origin

+

| : x-coordinate of the lattice origin [in cm]

|-

| <tt>''Y0''</tt>

−

| : y-coordinate of the lattice origin

+

| : y-coordinate of the lattice origin [in cm]

|-

| <tt>''NL''</tt>

Line 1,016:

Line 1,885:

|-

| <tt>''Zn''</tt>

−

| : z-coordinate of the n:th lattice element (lower boundary of the axial layer)

+

| : z-coordinate of the ''n''-th lattice element (lower boundary of the axial layer) [in cm]

|-

| <tt>''UNIn''</tt>

−

| : universe name filling the n:th lattice position

+

| : universe name filling the ''n''-th lattice position

|}

Possible lattice types are:

−

{| class="wikitable" style="text-align: left;"

+

::{| class="wikitable" style="text-align: left;"

! Type

! Description

Line 1,035:

Line 1,904:

*Space below the lowest z-coordinate is not defined.

*The top layer fills the entire space above the highest z-coordinate.

−

*The number of ''Zn-UNIn'' pairs must be NL.

+

*The number of ''Zn-UNIn'' pairs must be ''NL''.

−

~~'''lat''' ''UNI TYPE X0 Y0 Z0 NX NY NZ PITCHX PITCHY PITCHZ UNI1 UNI2 ...''~~

−

~~Defines a~~ finite ~~three-dimensional~~ lattice in xyz-space with cuboidal or X- or Y-type hexagonal prism elements.

+

Case V:

+

finite 3D lattice in xyz-space with cuboidal or X- or Y-type hexagonal prism elements

+

'''lat''' ''UNI TYPE X0 Y0 Z0 NX NY NZ PITCHX PITCHY PITCHZ UNI1 UNI2 ...''

{|

−

~~| <tt>''UNI''</tt>~~

−

~~| : universe name of the lattice~~

−

|-

−

~~| <tt>''TYPE''</tt>~~

−

~~| : lattice type~~

−

|-

| <tt>''X0''</tt>

−

| : x-coordinate of the lattice origin

+

| : x-coordinate of the lattice origin [in cm]

|-

| <tt>''Y0''</tt>

−

| : y-coordinate of the lattice origin

+

| : y-coordinate of the lattice origin [in cm]

|-

| <tt>''Z0''</tt>

−

| : z-coordinate of the lattice origin

+

| : z-coordinate of the lattice origin [in cm]

|-

| <tt>''NX''</tt>

Line 1,067:

Line 1,932:

|-

| <tt>''PITCHX''</tt>

−

| : lattice pitch in x-direction

+

| : lattice pitch in x-direction [in cm]

|-

| <tt>''PITCHY''</tt>

−

| : lattice pitch in y-direction

+

| : lattice pitch in y-direction [in cm]

|-

| <tt>''PITCHZ''</tt>

−

| : lattice pitch in z-direction

+

| : lattice pitch in z-direction [in cm]

|-

| <tt>''UNIn''</tt>

Line 1,080:

Line 1,945:

Possible lattice types are:

−

{| class="wikitable" style="text-align: left;"

+

::{| class="wikitable" style="text-align: left;"

! Type

! Description

Line 1,095:

Line 1,960:

Notes:

−

*Number of universes in list of universes must be NX times NY times NZ.

+

*Number of universes in list of universes must be ''NX × NY × NZ''.

*For hexagonal prism lattices the x- and y-direction pitches must be equal.

+

*The universe indexing is the similar as with lattice types 1-3. The lowermost z-level is given first, and the uppermost z-level is given last.

=== mat (material definition) ===

Line 1,103:

Line 1,969:

'''mat''' ''NAME DENS'' [ [[#mat_tmp|'''tmp''']] ''TEMP'' ]

+

[ [[#mat_tms|'''tms''']] ''TEMP'' ]

[ [[#mat_tft|'''tft''']] ''TMIN'' ''TMAX'' ]

[ [[#mat_rgb|'''rgb''']] ''R G B'' ]

[ [[#mat_vol|'''vol''']] ''VOL'' ]

+

[ [[#mat_mass|'''mass''']] ''MASS'' ]

[ [[#mat_burn|'''burn''']] ''NR'' ]

[ [[#mat_fix|'''fix''']] ''ID'' ''TEMP'' ]

+

[ [[#mat_moder|'''moder''']] ''THNAME'' ''ZA'' ]

''NUC1 FRAC1''

[ ''NUC2 FRAC2'' ]

[ ''...'' ]

−

~~Mandatory information~~:~~~~

+

Material definition. The mandatory parameters are:

{|

| <tt>''NAME''</tt>

−

| : ~~Name~~ of the material

+

| : name of the material

|-

| <tt>''DENS''</tt>

−

| : ~~Density~~ of the material (positive ~~for~~ atomic, negative ~~for~~ mass density~~) or '''~~<tt>~~sum~~</tt>~~''' to calculate the density from given nuclide fractions~~

+

| : density of the material (positive value = atomic density [in b-1cm-1], negative value = mass density [in g/cm3])

|-

−

| <tt>''NUC1''</tt>

+

| <tt>''NUCn''</tt>

−

| : Identifier of ~~first~~ nuclide in composition~~, e.g. "92235.03c" or "U-235.03c".~~

+

| : Identifier of ''n''-th nuclide in composition

|-

−

| <tt>''FRAC1''</tt>

+

| <tt>''FRACn''</tt>

−

| : ~~Fraction~~ of ~~first~~ nuclide in composition, positive ~~values are interpreted as~~ atomic fractions/~~densities~~, negative values as mass fractions/~~densities.~~

+

| : fraction of ''n''-th nuclide in composition (positive value = atomic fractions/density, negative values = mass fractions/density)

|-

|}

−

~~Optional cards:~~

+

The remaining parameters are defined by separate key words followed by the input values, being optional.

−

'''tmp''': ~~Material temperature for [[Doppler-broadening preprocessor routine|Doppler-preprocessor]]~~

+

Notes:

+

*There is a special entry for the <tt>''DENS''</tt> parameter:

+

** "<tt>sum</tt>": to calculate the density from given nuclide fractions

+

*The nuclide identifier for nuclides with associated cross-sections corresponds to ZZAAA.ID and, for nuclides without associated cross-sections, e.g., decay nuclides, to ZZAAAI.

+

**The identifiers include ''Z'', the atomic number; ''A'', the mass number of the nuclide; ''I'', the isomeric state (0 = ground state, 1 = metastable state); and ''ID'', the library identifier.

+

*For more information, see the detailed description on [[Definitions, units and constants#Definitions|Definitions]].

+

Optional entries:

+

Material temperature for Doppler-broadening pre-processor (<tt>'''tmp'''</tt>):

{|

| <tt>''TEMP''</tt>

−

| : ~~Temperature~~ of the material ~~for~~ [~~[Doppler-broadening preprocessor routine|Doppler-broadening preprocessor]~~]

+

| : temperature of the material [in K]

|}

−

'''~~tft~~''': ~~Temperature limits for~~ material for [[~~Coupled multi~~-~~physics calculations~~|coupled multi-physics calculations]]

+

Notes:

+

*It defines the material temperature for [[Doppler-broadening preprocessor routine|Doppler-preprocessor]].

+

Material temperature for on-the-fly temperature treatment (<tt>'''tms'''</tt>):

+

{|

+

| <tt>''TEMP''</tt>

+

| : temperature of the material [in K]

+

|}

+

Notes:

+

*It defines the material temperature for on-the-fly [[TMS on-the-fly temperature treatment routine‏‎|TMS temperature treatment]].

+

Material temperature for coupled multi-physics calculations (<tt>'''tft'''</tt>):

{|

| <tt>''TMIN''</tt>

−

| : ~~Lower~~ limit for material temperature

+

| : lower limit for material temperature [in K]

|-

| <tt>''TMAX''</tt>

−

| : ~~Upper~~ limit for material temperature

+

| : upper limit for material temperature [in K]

|}

−

'''rgb''': ~~Material color for [[#plot|geometry plots]]~~

+

Notes:

+

*It sets the temperature limits for material for [[Coupled multi-physics calculations|coupled multi-physics calculations]].

+

*It is used to define the minimum and maximum temperature for the TMS-treatment directly from the interface files (see [[#ifc|ifc]] card).

+

*For more information, see the detailed description on the [[multi-physics interface| Multi-physics interface]].

+

Material RGB-color (<tt>'''rgb'''</tt>):

{|

| <tt>''R''</tt>

−

| : ~~Value~~ for the red channel ~~of [[#plot|geometry plots]]~~ (between 0 and 255)

+

| : value for the red channel (between 0 and 255)

|-

| <tt>''G''</tt>

−

| : ~~Value~~ for the green channel ~~of geometry plots~~ (between 0 and 255)

+

| : value for the green channel (between 0 and 255)

|-

| <tt>''B''</tt>

−

| : ~~Value~~ for the blue channel ~~of geometry plots~~ (between 0 and 255)

+

| : value for the blue channel (between 0 and 255)

|}

−

'''vol''': ~~Material volume~~

+

Notes:

+

*It assigns a dedicated RGB-color to the material for the material representation in [[#plot|geometry plots]].

+

*If the entry is not provided, the material color is sampled randomly.

+

Material volume (<tt>'''vol'''</tt>):

{|

| <tt>''VOL''</tt>

−

| : ~~Volume~~ of the material in cm3 (3D geometry) or cross-sectional area in cm2 (2D geometry)

+

| : volume of the material [in cm3] (3D geometry) or cross-sectional area [in cm2] (2D geometry)

|}

−

'''~~burn~~''': ~~Flag~~ material ~~for~~ depletion

+

Notes:

+

*It defines the material volume.

+

*Alternatives ways to provide the material volume includes:

+

** [[#set mvol|set mvol]] option, used to define the material volumes manually

+

** [[#set mcvol|set mcvol]] option, used to define the material volumes automatically using the Monte Carlo checker routine at runtime.

+

** [[Installing and running Serpent#Monte Carlo volume calculation routine|<tt>''-checkvolumes''</tt>]] command line option, used to evaluate the material volumes in an independent run.

+

*For more information, see the detailed description on [[defining material volumes|material volumes definition]].

+

Material mass (<tt>'''mass'''</tt>):

+

{|

+

| <tt>''MASS''</tt>

+

| : mass of the material [in g]

+

|}

+

Notes:

+

*The material mass can be provided as an alternative to the material volume.

+

Material depletion flag (<tt>'''burn'''</tt>):

{|

| <tt>''NR''</tt>

−

| : ~~Set~~ to ~~1 in order to deplete~~ material. The ~~depletion zone division should be done using the [[#div~~|~~div]]~~-~~card.~~

+

| : option to flag the material as burnable (1/yes) or non-burnable (0/no). The default option is "<tt>non-burnable</tt>"

+

|-

|}

−

'''fix''': ~~Library information for decay nuclides~~

+

Notes:

+

*In order to deplete the material and include it in the burnup calculation, the flag must be set to "<tt>1</tt>"

+

*The depletion zone division should be done using the [[#div|div]] card. However,

+

** if a material is defined within a pin-structure, Serpent, by default if no [[#div|div]] card is associated to the material, sub-divides the material in a pin-type level.

+

** in Serpent 1, the "flag" is interpreted as the number of annular regions (not recommended)

+

Material library information for nuclides without cross section data (<tt>'''fix'''</tt>):

{|

| <tt>''LIB''</tt>

−

| : ~~Library~~ ID (e.g. "09c") for nuclides without cross section data.

+

| : library ID (e.g. "09c") for nuclides without cross section data.

|-

| <tt>''TEMP''</tt>

−

| : ~~Temperature (~~in ~~Kelvin)~~ for nuclides without cross section data.

+

| : temperature for nuclides without cross section data [in K]

+

|}

+

Notes:

+

*It defines the library properties: identifier and temperature for the nuclides without cross section data, e.g. decay nuclides, within the material composition.

+

Material associated thermal-scattering data (<tt>'''moder'''</tt>):

+

{|

+

| <tt>''THNAME''</tt>

+

| : name of the [[#therm_and_thermstoch_.28thermal_scattering.29|thermal scattering data library]]

+

|-

+

| <tt>''ZA''</tt>

+

| : nuclide ZA of the thermal scatterer (e.g. 1001 for H-1).

|}

Notes:

−

*~~This description is incomplete~~ for ~~both~~ the ~~descriptions and optional settings~~.

+

*It links the thermal-scattering data library for a given nuclide within the material composition.

−

*~~See [[defining material volumes]]~~ and [[#~~set mvol~~|~~set mvol~~]] ~~regarding other ways to set the~~ material ~~volumes for for example burnup calculations~~.

+

*The thermal-scattering data library and the associated temperature treatment is defined by the [[#therm_and_thermstoch_.28thermal_scattering.29|therm]] card.

+

*A single material can include multiple "<tt>moder</tt>" entries to define thermal-scattering libraries form multiple nuclides, such as H-H20 and D-D20 in semi-heavy water.

=== mesh (mesh plot definition) ===

Line 1,204:

Line 2,152:

|-

| <tt>''XPIX''</tt>

−

| : horizontal image size in pixels

+

| : horizontal image size [in pixels]

|-

| <tt>''YPIX''</tt>

−

| : vertical image size in pixels

+

| : vertical image size [in pixels]

|-

| <tt>''SYM''</tt>

Line 1,213:

Line 2,161:

|-

| <tt>''MINn'' ''MAXn''</tt>

−

| : boundaries of the plotted region

+

| : boundaries of the plotted region [in cm]

|-

| <tt>''CMAP''</tt>

Line 1,231:

Line 2,179:

*Some special detector types, such as pulse-height detectors and analog photon heating detectors cannot be associated with mesh plots.

*The mesh plot always produces results that are integrated over space. If no boundaries are provided, the integration is carried over the entire geometry.

−

*Setting the orientation parameter of a detector mesh plot to 4 produces a plot in cylindrical coordinates. Instead of Cartesian boundaries the entered values are then the radius~~, angle~~ and axial coordinate.

+

*Setting the orientation parameter of a detector mesh plot to 4 produces a plot in cylindrical coordinates. Instead of Cartesian boundaries the entered values are then the radius and axial coordinate.

*The symmetry option was used in Serpent 1. The parameter must be provided for Serpent 2 as well, even though it is not used. The value can be set to zero.

−

*Mesh plot produced by the ~~n:th~~ mesh-card is written in file <tt>[input]_mesh[n].png</tt>.

+

*Mesh plot produced by the nth mesh-card is written in file <tt>[input]_mesh[n].png</tt>.

+

=== mflow (material flow definition) ===

+

'''mflow''' ''NAME''

+

''NUC1'' ''λ1''

+

[ ''NUC2'' ''λ2'' ]

+

[ ''...'' ]

+

Defines the material flow. Input values:

+

{|

+

| <tt>''NAME''</tt>

+

| : name of the material flow

+

|-

+

| <tt>''NUCn''</tt>

+

| : identifier of <tt>''n''</tt>-th nuclide in composition

+

|-

+

| <tt>''λ''n</tt>

+

| : reprocessing constant of <tt>''n''</tt>-th nuclide in composition [in s-1]

+

|}

+

Notes:

+

* The nuclide ID should follow the [[Definitions, units and constants#definitions|ZAI]] or ISO format (e.g., 922350 or U-235).

+

* There is a special entry for the nuclide ID:

+

** "<tt>all</tt>": in which case all nuclides are included with the same reprocessing fraction ''λ''.

=== mix (mixture definition) ===

−

'''mix''' ''NAME''

+

'''mix''' ''NAME'' [ [[#mix_rgb|'''rgb''']] ''R G B'' ]

+

[ [[#mix_vol|'''vol''']] ''VOL'' ]

+

[ [[#mix_mass|'''mass''']] ''MASS'' ]

''MAT1'' ''F1''

''MAT2'' ''F2''

...

−

Defines a mixture of two or several materials. ~~Input~~ values:

+

Defines a mixture of two or several materials. Mandatory input values:

{|

Line 1,248:

Line 2,223:

|-

| <tt>''Fn''</tt>

−

| : material fraction (positive ~~values for~~ volume, negative ~~values for~~ mass ~~fractions~~)

+

| : material fraction (positive value = volume fraction, negative value = mass fraction)

|-

|}

+

The remaining parameters are defined by separate key words followed by the input values, being optional.

Notes:

*Mixtures can be used to define complicated material definitions consisting of two or more physical materials mixed homogeneously.

−

*~~Serpent decomposes these~~ mixtures into standard materials before running the transport simulation.

+

*The mixtures are automatically decomposed into standard materials before running the transport simulation.

−

*~~The~~ decomposed material compositions can be written into file using the [[Installing and running Serpent#Running Serpent|-mix]] command line option.

+

**Alternatively, the decomposed material compositions can be written into file using the [[Installing and running Serpent#Running Serpent|<tt>''-mix''</tt>]] command line option.

+

*Inherited properties/cards:

+

**Nuclide specific thermal scattering data (see '''moder''' entry in the [[#mat_moder|mat]] card) is automatically brought from component materials to the mixture.

+

**Other input option such as [[#set_trc|set trc]], [[#set_iter_nuc|set iter nuc]], [[Sensitivity_calculations#Choosing_materials_to_perturb|sens pert matlist]] are not automatically inherited by the mixture from the components.

+

**If they are to be applied to the mixture, they should be directly defined using the mixture material name (opposed to component material names) .

+

*Burnable mixtures are not supported.

+

Optional entries:

+

Mixture RGB-color (<tt>'''rgb'''</tt>):

+

{|

+

| <tt>''R''</tt>

+

| : value for the red channel (between 0 and 255)

+

|-

+

| <tt>''G''</tt>

+

| : value for the green channel (between 0 and 255)

+

|-

+

| <tt>''B''</tt>

+

| : value for the blue channel (between 0 and 255)

+

|}

+

Notes:

+

*RGB color coding for material representation in [[#plot|geometry plots]].

+

Mixture volume (<tt>'''vol'''</tt>):

+

{|

+

| <tt>''VOL''</tt>

+

| : volume of the material [in cm3] (3D geometry) or cross-sectional area [in cm2] (2D geometry)

+

|}

+

Mixture mass (<tt>'''mass'''</tt>):

+

{|

+

| <tt>''MASS''</tt>

+

| : mass of the material [in g]

+

|}

=== nest (nested universe definition) ===

−

'''nest''' ''U'' ''TYPE''

+

'''nest''' ''UNI0'' ''TYPE''

[ ''MAT1'' ''R1'' ]

[ ''MAT2'' ''R2'' ]

Line 1,266:

Line 2,283:

[ ''MATN'' ]

−

'''nest''' ''U''

+

'''nest''' ''UNI0''

[ ''MAT1'' ''TYPE1'' ''PARAM11 PARAM12'' ... ]

[ ''MAT2'' ''TYPE2'' ''PARAM21 PARAM22'' ... ]

Line 1,275:

Line 2,292:

{|

−

| <tt>''U''</tt>

+

| <tt>''UNI0''</tt>

| : universe name

|-

Line 1,285:

Line 2,302:

|-

| <tt>''R1 ... RN-1''</tt>

−

| : outer radii

+

| : outer radii [in cm]

|-

| <tt>''TYPE1 ... TYPEN-1''</tt>

| : nested surface type (different surfaces for each region)

|-

−

| <tt>''PARAMnm ... </tt>

+

| <tt>''PARAMnm'' ... </tt>

| : surface parameters

|}

Line 1,296:

Line 2,313:

Notes:

−

*The nest card defines an entire universe consisting of nested material regions. The boundaries are defined by surfaces nested inside each other. The outermost region is infinite.

+

*The nest card defines an entire universe consisting of nested material regions.

−

*~~The~~ material entries can be replaced by <tt>~~'''~~fill''~~' ''U~~0''</tt>, in which case the region is filled by another universe.

+

**The boundaries are defined by surfaces nested inside each other.

−

*The first format allows defining nests in which all surfaces are of same type and centred at the origin. Only surfaces that are characterized by a single outer radius are accepted ([[Surface_types#Second-order_quadratic_surfaces|cylinders, spheres]] and some [[Surface_types#Regular_prisms|regular prisms]]). The [[#pin (pin geometry definition)|pin]] and [[#particle (particle geometry definition)|particle]] definitions are short-hand notations of the nest card.

+

**The outermost region is infinite.

+

*Special <tt>''MATi''</tt> entry: the material entries can be replaced by "<tt>fill ''UNIi''</tt>", in which case the region is filled by another universe, <tt>''UNIi''</tt>.

+

*The first format allows defining nests in which all surfaces are of same type and centred at the origin.

+

**Only surfaces that are characterized by a single outer radius are accepted ([[Surface_types#Second-order_quadratic_surfaces|cylinders, spheres]] and some [[Surface_types#Regular_prisms|regular prisms]]).

+

**The [[#pin (pin geometry definition)|pin]] and [[#particle (particle geometry definition)|particle]] definitions are short-hand notations of the nest card.

*The second format allows mixing different surface types. In this case all surface parameters need to be provided after the surface type.

=== particle (particle geometry definition) ===

−

'''particle''' ''U''

+

'''particle''' ''UNI0''

[ ''MAT1'' ''R1'' ]

[ ''MAT2'' ''R2'' ]

Line 1,311:

Line 2,332:

{|

−

| <tt>''U''</tt>

+

| <tt>''UNI0''</tt>

| : universe name

|-

Line 1,318:

Line 2,339:

|-

| <tt>''R1 ... RN-1''</tt>

−

| : outer radii

+

| : outer radii [in cm]

|}

Notes:

−

*The particle card defines an entire universe consisting of nested spherical shells. The boundaries are defined by sphere surfaces. The outermost region is radially infinite.

+

*The particle card defines an entire universe consisting of nested spherical shells.

−

*~~The~~ material entries can be replaced by <tt>~~'''~~fill''~~' ''U~~0''</tt>, in which case the region is filled by another universe.

+

**The boundaries are defined by sphere surfaces.

+

**The outermost region is radially infinite.

+

*Special <tt>''MATi''</tt> entry: the material entries can be replaced by "<tt>fill ''UNIi''</tt>", in which case the region is filled by another universe, <tt>''UNIi''</tt>.

*Most typically used for defining TRISO fuel particles.

*The particle card is special case of a [[#nest (nested universe definition)|nested universe type]].

*See also description of [[#pbed (explicit stochastic geometry)|explicit stochastic geometry type]].

−

=== pbed (explicit stochastic (pebble bed) geometry) ===

+

=== pbed (explicit stochastic (pebble bed) geometry definition) ===

+

'''pbed''' ''UNI0'' ''UNIbg'' ''FILE'' [ ''OPT'' ]

+

Defines a stochastic particle / pebble-bed geometry. Input values:

+

{|

+

| <tt>''UNI0''</tt>

+

| : universe name for the dispersed medium

+

|-

+

| <tt>''UNIbg''</tt>

+

| : background universe, i.e. universe filling the space between particles / pebbles

+

|-

+

| <tt>''FILE''</tt>

+

|: input file containing the particle/pebble data

+

|-

+

| <tt>''OPT''</tt>

+

|: additional options

+

|}

+

The syntax of the file containing the particle/pebble data is:

+

::{| class="toccolours" style="text-align: left;"

+

| ''X1'' ''Y1'' ''Z1'' ''R1'' ''UNI1''

+

|-

+

| ''X2'' ''Y2'' ''Z2'' ''R2'' ''UNI2''

+

|-

+

| ...

+

|-

+

|}

+

where:

+

{|

+

|<tt>''Xn'', ''Yn'', ''Zn''</tt>

+

|: are the coordinates [in cm]

+

|-

+

|<tt>''Rn''</tt>

+

|: is the radius [in cm]

+

|-

+

|<tt>''UNIn''</tt>

+

|: is the universe

+

|}

+

The supported additional options are:

+

::{| class="wikitable" style="text-align: left;"

+

! Option

+

! Description

+

|-

+

| <tt>pow</tt>

+

| power distribution

+

|-

+

|}

+

Notes:

+

*Creates a universe (<tt>''UNI0''</tt>), which is filled with spherical sub-universes for which the coordinates are read from a separate file.

+

*The coordinates can be defined manually, or using the [[Installing_and_running_Serpent#Running Serpent|<tt>''-disperse''</tt>]] command line option which launches the particle disperser routine.

+

*Can be used for modelling stochastic particle / pebble-bed geometries in multiple levels.

+

*If the "<tt>pow</tt>" (power distribution) option is set, the pebble/particle-wise distribution is written in file <tt>[''FILE'']_pow[bu].m</tt>, where "<tt>bu</tt>" is the burnup step, from version 2.2.1 and on (in previous versions, <tt>[''FILE''].out</tt>).

+

*See also [[Collection_of_example_input_files#Simple_burnup_examples|HTGR geometry examples]].

+

=== phb (pulse-height Gaussian energy broadening definition) ===

+

'''phb''' ''NAME'' ''TYPE'' [ ... ]

+

Defines a user-defined (Gaussian) energy broadening function for pulse-height detector ([[#det_dphb|'''dphb''']]). Input values:

+

{|

+

|<tt>''NAME''</tt>

+

|: pulse-height (Gaussian) energy broadening function name

+

|-

+

|<tt>''TYPE''</tt>

+

|: pulse-height function type

+

|}

+

The remaining input values are type-dependent.

+

The pulse-height funtion types are:

+

::{| class="wikitable" style="text-align: left;"

+

! Type

+

! Description

+

|-

+

| [[#phb_1|<tt>1</tt>]]

+

| energy-resolution interpolation

+

|-

+

| [[#phb_2|<tt>2</tt>]]

+

| energy-FWHM interpolation

+

|-

+

| [[#phb_3|<tt>3</tt>]]

+

| energy-resolution fitting

+

|-

+

| [[#phb_4|<tt>4</tt>]]

+

| energy-FWHM fitting

+

|-

+

|}

+

The syntax for the available types is as follows:

+

'''phb''' ''NAME'' '''1''' ''INTT'' ''Emax,1'' ''R1'' ''Emax,2'' ''R2'' ...

+

{|

+

|<tt>''INTT''</tt>

+

|: is the interpolation type (currently only supported type is 2 = lin-lin interpolation data)

+

|-

+

|<tt>''Emax,i, Ri''</tt>

+

|: are the maximum energy-resolution tabulated pairs [in MeV (energy)]

+

|}

+

Notes:

+

* Full width at half maximum is calculated as: <math> FWHM(E_{max,i}) = R(E_{max,i}) E_{max,i} </math>

+

* Energies should be given in ascending order.

+

'''phb''' ''NAME'' '''2''' ''INTT'' ''Emax,1'' ''FWHM1'' ''Emax,2'' ''FWHM2'' ...

+

{|

+

|<tt>''INTT''</tt>

+

|: is the interpolation type (currently only supported type is 2 = lin-lin interpolation data)

+

|-

+

|<tt>''Emax,i, FWHMi''</tt>

+

|: are the maximum energy-full width at half maximum pairs [in MeV (energy)]

+

|}

+

Notes:

+

* Energies should be given in ascending order.

+

'''phb''' ''NAME'' '''3''' ''a'' ''b''

+

{|

+

|<tt>''a, b''</tt>

+

|: are the parameters to define the energy resolution fit: <math> R = aE^b </math>

+

|}

+

'''phb''' ''NAME'' '''4''' ''a'' ''b'' ''c''

+

{|

+

|<tt>''a, b, c''</tt>

+

|: are the parameters to define the energy full width at half maximum fit: <math> FWHM = a + b\sqrt{(E + cE^2)} </math>

+

|}

=== pin (pin geometry definition) ===

−

'''pin''' ''U''

+

'''pin''' ''UNI0''

[ ''MAT1'' ''R1'' ]

[ ''MAT2'' ''R2'' ]

Line 1,341:

Line 2,502:

{|

−

| <tt>''U''</tt>

+

| <tt>''UNI0''</tt>

| : universe name

|-

Line 1,348:

Line 2,509:

|-

| <tt>''R1 ... RN-1''</tt>

−

| : outer radii

+

| : outer radii [in cm]

|}

Notes:

−

*The pin card defines an entire universe consisting of nested annular material regions. The boundaries are defined by axially infinite cylindrical surfaces. The outermost region is radially infinite.

+

*The pin card defines an entire universe consisting of nested annular material regions.

−

*~~The~~ material entries can be replaced by <tt>~~'''~~fill''~~' ''U~~0''</tt>, in which case the region is filled by another universe.

+

**The boundaries are defined by axially infinite cylindrical surfaces.

+

**The outermost region is radially infinite.

+

*Special <tt>''MATi''</tt> entry: the material entries can be replaced by "<tt>fill ''UNIi''</tt>", in which case the region is filled by another universe, <tt>''UNIi''</tt>.

*Most typically used for defining fuel pins, but can also be applied to guide tubes, control rods, etc.

*The pin card is special case of a [[#nest (nested universe definition)|nested universe type]].

Line 1,371:

Line 2,534:

|-

| <tt>''XPIX''</tt>

−

| : horizontal image size in pixels

+

| : horizontal image size [in pixels]

|-

| <tt>''YPIX''</tt>

−

| : vertical image size in pixels

+

| : vertical image size [in pixels]

|-

| <tt>''POS''</tt>

−

| : position of plot plane

+

| : position of plot plane [in cm]

|-

| <tt>''MIN1''</tt>

−

| : minimum horizontal coordinate of plotted region

+

| : minimum horizontal coordinate of plotted region [in cm]

|-

| <tt>''MAX1''</tt>

−

| : maximum horizontal coordinate of plotted region

+

| : maximum horizontal coordinate of plotted region [in cm]

|-

| <tt>''MIN2''</tt>

−

| : minimum vertical coordinate of plotted region

+

| : minimum vertical coordinate of plotted region [in cm]

|-

| <tt>''MAX2''</tt>

−

| : maximum vertical coordinate of plotted region

+

| : maximum vertical coordinate of plotted region [in cm]

|-

| <tt>''Fmin''</tt>

Line 1,398:

Line 2,561:

|-

| <tt>''E''</tt>

−

| : particle energy for importance map plots

+

| : particle energy for importance map plots [in MeV]

|}

Notes:

−

*The ~~type~~ parameter consists of one or two concatenated values ('AB'):

+

*The <tt>''TYPE''</tt> parameter consists of one ('A') or two concatenated values ('AB'):

−

*#The first value ('A') defines the plot plane (~~1 =~~ yz~~, 2~~ = xz, 3 = xy).

+

**The first value ('A') defines the plot plane (yz-plot = 1, "<tt>x</tt>", xz-plot = 2, "<tt>y</tt>", xy-plot = 3, "<tt>z</tt>").

−

*#The second value ('B') defines which boundaries are plotted (0 = no boundaries, 1 = cell boundaries, 2 = material boundaries, 3 = both). If the second value in is not provided, material boundaries ~~are~~ plotted.

+

**The second value ('B') defines which boundaries are plotted (0 = no boundaries, 1 = cell boundaries, 2 = material boundaries, 3 = both cell and material boundaries).

−

*~~Importance~~ maps read using the [[#wwin (weight window mesh definition)|wwin card]] can be plotted on top of the geometry by setting the second value ('B') of the type parameter to 4 (linear color scheme) or 5 (logarithmic color scheme). The input parameters ~~then also~~ include the minimum and maximum importance and the particle energy. If importance maps are provided for both neutrons and photons, they can be plotted by entering positive and negative energy values, respectively.

+

***If the second value ('B') is not provided, default value 2 = material boundaries is used.

−

*Each material plotted with different color. The colors are sampled randomly, unless defined using the rgb entry in the [[#mat (material definition)|~~material~~ card]].

+

*The relative dimensions of image size (<tt>''XPIX''</tt>, <tt>''YPIX''</tt>) should match that of the plotted region. Otherwise the image gets distorted.

−

*~~Void is plotted in black and special~~ colors ~~are used to plot geometry errors (red~~ = ~~overlap, green~~ = ~~undefined region).~~

+

*The position parameter <tt>''POS''</tt> defines the location of the plot plane on the axis perpendicular to it (e.g. z-coordinate for xy-type plot).

−

*The position parameter defines the location of the plot plane on the axis perpendicular to it (~~e.g. z~~-~~coordinate for xy~~-~~type plot~~).

+

*The minimum and maximum coordinates: <tt>''MINn''</tt>, <tt>''MAXn''</tt>, define the boundaries of the plotted region (e.g. minimum and maximum x- and y-coordinates for xy-type plot).

−

*The minimum and maximum coordinates ~~define the boundaries of the plotted region (e.g. minimum and maximum x- and y~~-coordinates ~~for xy~~-~~type plot~~)~~. If these~~ coordinates ~~are not provided, the plot is extended to the maximum dimensions of the geometry.~~

+

** If the coordinates are not provided, the plot is extended to the maximum dimensions of the geometry.

−

*The relative dimensions of image size in pixels should match that of the plotted region. Otherwise the image gets distorted.

+

−

*Geometry plotter requires compiling the source code with [[~~Compiling~~ Serpent|GD Graphics libraries]].

+

*The second format allows to plot he importance maps read using the [[#wwin (weight window mesh definition)|wwin card]]:

−

*[[Installing and running Serpent#Running Serpent|~~Command line parameter]]~~ '-plot' stops the execution after the geometry plots are produced~~. Option~~ '-qp' invokes a quick plot mode, which does not check for overlaps~~. Option~~ '-noplot' skips the geometry plots altogether.

+

**They can be plotted on top of the geometry by setting the second value ('B') of the type parameter for:

+

*** Cell importances: 4 (linear color scheme) or 5 (logarithmic color scheme)

+

*** Source importances: 6 (linear color scheme) or 7 (logarithmic color scheme)

+

**The input parameters include the minimum and maximum importance (<tt>''Fmin''</tt>, <tt>''Fmax''</tt>) and the particle energy, <tt>''E''</tt>.

+

***If importance maps are provided for both neutrons and photons, they can be plotted by entering positive and negative energy values, respectively.

+

***If both, minimum and maximum importance values are set to "-1", Serpent automatically adjusts them based on the weight-window mesh data, from version 2.2.0 and on.

+

****If the calculation fails on providing those minimum and maximum values due to the weight-window evaluation, the values are set by default to (1E-200, 1E+200).

+

**''Note to developers: particle type should be included as an input parameter in importance map plots.''

+

*Material colors:

+

**Each material plotted with different color.

+

**The colors are sampled randomly, unless defined using the '''rgb''' entry in the material card (see [[#mat (material definition)|mat]]) or mixture card (see [[#mix (mixture definition)|mix]])

+

**Special RGB-colors:

+

::{|class="wikitable" style="text-align: left;"

+

! RGB value

+

! Color

+

! Description

+

|-

+

| (0, 0, 0)

+

| COLOR

+

| Outside cell or void-material

+

|-

+

| (0, 255, 0)

+

| COLOR

+

| No cell found at coordinates

+

|-

+

| (255, 0, 0)

+

| COLOR

+

| Overlap of multiple cells found at coordinates

+

|-

+

| (255, 0, 255)

+

| COLOR

+

| Undefined material density factor at coordinates

+

|}

+

*Geometry plotter requires compiling the source code with [[Installing and running Serpent#GD Graphics library|GD Graphics libraries]].

+

*Command line options:

+

**[[Installing and running Serpent#Running Serpent|<tt>''-plot''</tt>]] stops the execution after the geometry plots are produced

+

**[[Installing and running Serpent#Running Serpent|<tt>''-qp''</tt>]] invokes a quick plot mode, which does not check for overlaps

+

**[[Installing and running Serpent#Running Serpent|<tt>''-noplot''</tt>]] skips the geometry plots altogether

*See also [[Visualizing the results#Geometry plotter|detailed description]] on geometry plotter.

−

*~~Geometry~~ plot produced by the n:th plot-card is written in file <tt>[input]_geom[n].png</tt>.

+

*The geometry plot produced by the ''n''-th plot-card is written in file <tt>[input]_geom[n].png</tt>.

−

*''~~Note~~ to ~~developers~~: ~~particle type should be~~ included ~~as an input parameter~~ in ~~importance map plots~~.''

+

=== rep (reprocessor definition) ===

+

'''rep''' ''NAME''

+

[ [[#rep_rc|'''rc''']] ''SRC'' ''TGT'' ''MFLOW'' ''MODE'' ]

+

[ [[#rep_rm|'''rm''']] ''MAT1'' ''MAT2'' ]

+

[ [[#rep_ru|'''ru''']] ''UNI1'' ''UNI2'' ]

+

Defines the reprocessing controllers. The first parameter:

+

{|

+

| <tt>''NAME''</tt>

+

| : name of the reprocessor.

+

|}

+

The remaining parameters are defined by separate key words followed by the input values.

+

Notes:

+

*The reprocessor name identifies the reprocessing regime in the depletion calculation [[#dep|dep card]]. The syntax corresponds to '''dep pro''' ''NAME''.

+

*Multiple reprocessing controllers/regimes can be defined within the same reprocessor definition.

+

Reprocessing regime types:

+

Reprocessing continuos regime (<tt>'''rc'''</tt>):

+

{|

+

| <tt>''SRC''</tt>

+

| : name of the source material, from which the flow is moved

+

|-

+

| <tt>''TGT''</tt>

+

| : name of the target material, to which the flow is moved

+

|-

+

| <tt>''MFLOW''</tt>

+

| : name of the material flow

+

|-

+

| <tt>''MODE''</tt>

+

| : continuous reprocessing mode

+

|-

+

|}

+

Notes:

+

*The nuclides identifier of those included in both source <tt>''SRC''</tt> and target <tt>''TGT''</tt> materials in reprocessors should follow the same format

+

**ZA.ID or ISO.ID (for nuclides with cross sections) or ZAI (for nuclides without associated cross sections, and adding the '''fix''' entry to the [[#mat (material definition)|mat card]]).

+

**For more information, see the detailed description on [[Definitions, units and constants#definitions|Nuclide IDs]]).

+

*The continuous reprocessing regime works with materials, not universes. Therefore, define the universes associated with those burnable materials as surface-cell type universes.

+

*The continuous reprocessing regime can be used to define the material flow between the source and the target materials.

+

**The material flow is defined using the [[#mflow|mflow card]].

+

**The continuous reprocessing <tt>''MODE''</tt> defines how to incorporate the material flow into the Bateman equations:

+

::{|class="wikitable" style="text-align: center;"

+

! <tt>''MODE''</tt>

+

! Material source

+

! Material target

+

! Material flow

+

|-

+

| 0

+

| <math>N_{src}(t)=N_{src}(0)</math>

+

| <math>N_{tgt}(t)=N_{tgt}(0)+t\lambda N_{src}(0)</math>

+

| <math>\dot{N}(t)=\lambda N_{src}(0)</math>

+

|-

+

| 1

+

| <math>N_{src}(t)=N_{src}(0)e^{-\lambda t}</math>

+

| <math>N_{tgt}(t) = N_{tgt}(0) + (1-e^{-\lambda t})N_{src}(0)</math>

+

| <math>\dot{N}(t)=\lambda N_{src}(t)</math>

+

|-

+

| 2

+

| <math>N_{src}(n+1)=(1-\Delta t_{n}\lambda)N_{src}(n)</math>

+

| <math>N_{tgt}(n+1)=N_{tgt}(n)+\Delta t_{n}\lambda N_{src}(n)</math>

+

| <math>\dot{N}(n)=\lambda N_{src}(n)</math>

+

|}

+

:*<tt>''MODE''</tt> 0 : no changes at the source material and adds ''λN0'' from the source material to the target material when solving the Bateman equations (''N0'' are initial compositions).

+

:*<tt>''MODE''</tt> 1 : subtracts ''λN'' from the source material and adds it to the target material when solving the Bateman equations.

+

:*<tt>''MODE''</tt> 2 : subtracts ''λNn'' from the source material and adds it to the target material when solving the Bateman equations (compositions updated with each burnup step, ''n'').

+

Reprocessing material regime (<tt>'''rm'''</tt>):

+

{|

+

| <tt>''MAT1''</tt>

+

| : name of the replaced material

+

|-

+

| <tt>''MAT2''</tt>

+

| : name of the replacing material

+

|-

+

|}

+

Notes:

+

*The material reprocessing regime replaces one material with another, ''MAT1'' by ''MAT2''.

+

Reprocessing universe regime (<tt>'''ru'''</tt>):

+

{|

+

| <tt>''UNI1''</tt>

+

| : name of the replaced universe

+

|-

+

| <tt>''UNI2''</tt>

+

| : name of the replacing universe

+

|-

+

|}

+

Notes:

+

*The universe reprocessing regime replaces one universe with another, ''UNI1'' by ''UNI2''.

−

=== sample (~~Temperature~~ / density data sample definition) ===

+

=== sample (temperature / density data sample definition) ===

'''sample''' ''NX'' ''XMIN'' ''XMAX'' ''NY'' ''YMIN'' ''YMAX'' ''NZ'' ''ZMIN'' ''ZMAX''

Line 1,428:

Line 2,734:

{|

| <tt>''NX''</tt>

−

| : ~~Number~~ of values to sample in the x-direction.

+

| : number of values to sample in the x-direction.

|-

| <tt>''XMIN''</tt>

−

| : ~~Minimum~~ coordinate to sample from in the x-direction.

+

| : minimum coordinate to sample from in the x-direction [in cm]

|-

| <tt>''XMAX''</tt>

−

| : ~~Maximum~~ coordinate to sample from in the x-direction.

+

| : maximum coordinate to sample from in the x-direction [in cm]

|-

| <tt>''NY''</tt>

−

| : ~~Number~~ of values to sample in the y-direction.

+

| : number of values to sample in the y-direction.

|-

| <tt>''YMIN''</tt>

−

| : ~~Minimum~~ coordinate to sample from in the y-direction.

+

| : minimum coordinate to sample from in the y-direction [in cm]

|-

| <tt>''YMAX''</tt>

−

| : ~~Maximum~~ coordinate to sample from in the y-direction.

+

| : maximum coordinate to sample from in the y-direction [in cm]

|-

| <tt>''NZ''</tt>

−

| : ~~Number~~ of values to sample in the z-direction.

+

| : number of values to sample in the z-direction.

|-

| <tt>''ZMIN''</tt>

−

| : ~~Minimum~~ coordinate to sample from in the z-direction.

+

| : minimum coordinate to sample from in the z-direction [in cm]

|-

| <tt>''ZMAX''</tt>

−

| : ~~Maximum~~ coordinate to sample from in the z-direction.

+

| : maximum coordinate to sample from in the z-direction [in cm]

|-

|}

Line 1,458:

Line 2,764:

Notes:

−

*The data from each sample is written in a separate <tt>[input]_sample~~''N''~~.m</tt> ~~file~~.

+

*The data from each sample is written in a separate output file:

−

*~~Positive values for~~ the ~~density data correspond to~~ atomic densities, ~~while~~ negative ~~values correspond to~~ mass ~~densities~~.

+

**Default: <tt>[input]_sample[n].m</tt>, where "<tt>n</tt>" is the sample number.

−

*Materials with no temperature specified either in their [[~~Input syntax manual~~#mat|mat]]-card or through an interface definition will show a temperature of 0.

+

**Coupled multi-physics calculation: <tt>[input]_sample[n]_iter[i].m</tt>, where "<tt>i</tt>" is the iteration number.

+

**Burnup calculations: <tt>[input]_sample[n]_bstep[bu].m</tt>, where "<tt>bu</tt>" is the burnup step index.

+

*** Coupled multi-physics calculation: <tt>[input]_sample[n]_bstep[bu]_iter[i].m</tt>

+

**Time-dependent calculations: <tt>[input]_sample[n]_tstep[t].m</tt>, where "<tt>t</tt>" is the time step index

+

*** Coupled multi-physics calculation: <tt>[input]_sample[n]_tstep[t]_iter[i].m</tt>

+

*Sampling units:

+

** Density: positive values = atomic densities [in b-1 cm-1], negative value = mass density [in g/cm3].

+

** Temperature: [in K]

+

*Materials with no temperature specified either in their [[#mat|mat]] card or through an interface [[#ifc|ifc]] card definition will show a temperature of 0 K.

=== sens (sensitivity calculation definition) ===

Line 1,472:

Line 2,786:

=== solid (irregular 3D geometry definition) ===

−

'''solid 1''' ''UNI'' ''BGUNI''

+

'''solid 1''' ''UNI0'' ''BGUNI''

''MESH_SPLIT'' ''MESH_DIM'' ''SZ1'' ''SZ2'' ... ''SZMESH_DIM''

''POINTS_FILE''

Line 1,483:

Line 2,797:

{|

−

| <tt>''UNI''</tt>

+

| <tt>''UNI0''</tt>

| : universe name for the irregular geometry

|-

Line 1,490:

Line 2,804:

|-

| <tt>''MESH_SPLIT''</tt>

−

| : ~~Splitting~~ criterion for the adaptive search mesh (maximum number of geometry cells in search mesh cell)

+

| : splitting criterion for the adaptive search mesh (maximum number of geometry cells in search mesh cell)

|-

| <tt>''MESH_DIM''</tt>

Line 1,496:

Line 2,810:

|-

| <tt>''SZi''</tt>

−

| : ~~Size~~ of the search mesh at level <tt>''i''</tt>

+

| : size of the search mesh at level <tt>''i''</tt>

|-

| <tt>''POINTS_FILE''</tt>

−

| : ~~Path~~ to the unstructured mesh points file

+

| : path to the unstructured mesh points file

|-

| <tt>''FACES_FILE''</tt>

−

| : ~~Path~~ to the unstructured mesh faces file

+

| : path to the unstructured mesh faces file

|-

| <tt>''OWNER_FILE''</tt>

−

| : ~~Path~~ to the unstructured mesh owner file

+

| : path to the unstructured mesh owner file

|-

| <tt>''NEIGHBOUR_FILE''</tt>

−

| : ~~Path~~ to the unstructured mesh neighbour file

+

| : path to the unstructured mesh neighbour file

|-

| <tt>''MATERIALS_FILE''</tt>

−

| : ~~Path~~ to the unstructured mesh materials file

+

| : path to the unstructured mesh materials file

|}

+

Notes:

+

*For more information on the unstructured mesh based geometry see [[Unstructured mesh based input]].

+

*For a practical example: [[Simple umsh 8 cubes input]].

−

'''solid 2''' ''UNI'' ''BGUNI''

+

'''solid 2''' ''UNI0'' ''BGUNI''

''MESH_SPLIT'' ''MESH_DIM'' ''SZ1'' ''SZ2'' ... ''SZMESH_DIM''

''MODE'' ''R0''

Line 1,530:

Line 2,847:

{|

−

| <tt>''UNI''</tt>

+

| <tt>''UNI0''</tt>

| : universe name for the irregular geometry

|-

Line 1,537:

Line 2,854:

|-

| <tt>''MESH_SPLIT''</tt>

−

| : ~~Splitting~~ criterion for the adaptive search mesh (maximum number of geometry cells in search mesh cell)

+

| : splitting criterion for the adaptive search mesh (maximum number of geometry cells in search mesh cell)

|-

| <tt>''MESH_DIM''</tt>

Line 1,546:

Line 2,863:

|-

| <tt>''MODE''</tt>

−

| : ~~Mode~~ for handling the triangulated geometry (1 = "fast", 2 = "safe").

+

| : mode for handling the triangulated geometry (1 = "fast", 2 = "safe").

|-

| <tt>''R0''</tt>

−

| : ~~Radius~~ inside which two points of the STL-geometry are joined into one.

+

| : radius inside which two points of the STL-geometry are joined into one.

|-

| <tt>''BODYi''</tt>

−

| : ~~Name~~ of solid body <tt>''i''</tt>

+

| : name of solid body <tt>''i''</tt>

|-

| <tt>''CELLi''</tt>

−

| : ~~Name~~ of geometry cell <tt>''i''</tt> linked with body <tt>''i''</tt>

+

| : name of geometry cell <tt>''i''</tt> linked with body <tt>''i''</tt>

|-

| <tt>''MATi''</tt>

−

| : ~~Material~~ filling cell <tt>''i''</tt>

+

| : material filling cell <tt>''i''</tt>

|-

| <tt>''FILEi''</tt>

−

| : ~~Path~~ to a file containing an STL solid model, multiple files can be linked to one body

+

| : path to a file containing an STL solid model, multiple files can be linked to one body

|-

| <tt>''SCALEi''</tt>

−

| : ~~Scaling~~ factor for the STL model in <tt>''FILEi''</tt>

+

| : scaling factor for the STL model in <tt>''FILEi''</tt>

|-

| <tt>''Xi''</tt>

−

| : ~~Shift~~ in x-direction to the STL model in <tt>''FILEi''</tt>

+

| : shift in x-direction to the STL model in <tt>''FILEi''</tt>

|-

| <tt>''Yi''</tt>

−

| : ~~Shift~~ in y-direction to the STL model in <tt>''FILEi''</tt>

+

| : shift in y-direction to the STL model in <tt>''FILEi''</tt>

|-

| <tt>''Zi''</tt>

−

| : ~~Shift~~ in z-direction to the STL model in <tt>''FILEi''</tt>

+

| : shift in z-direction to the STL model in <tt>''FILEi''</tt>

|}

+

Notes:

+

*Special <tt>''MATi''</tt> entry: the material entries can be replaced by "<tt>fill ''UNIi''</tt>", in which case the region is filled by another universe, <tt>''UNIi''</tt>.

+

*For a practical example: [[Stanford critical bunny]].

'''solid 3'''

Line 1,583:

Line 2,904:

{|

| <tt>''INTERFACE_FILE''</tt>

−

| : ~~Path~~ to the [[Multi-physics_interface#Unstructured_mesh_based_interface_and_geometry_definition_.28type_9.29|interface file]] containing the rest of the parameters

+

| : path to the [[Multi-physics_interface#Unstructured_mesh_based_interface_and_geometry_definition_.28type_9.29|interface file]] containing the rest of the parameters

|}

+

Notes:

+

*For more information on the unstructured mesh based geometry see [[Unstructured mesh based input]].

+

*For a practical example: [[Simple umsh 8 cubes input]].

=== src (source definition) ===

Line 1,591:

Line 2,916:

[ [[#src_sw|'''sw''']] ''WGT'' ]

[ [[#src_sc|'''sc''']] ''CELL'' ]

+

[ [[#src_su|'''su''']] ''UNI'' ]

[ [[#src_sm|'''sm''']] ''MAT'' ]

[ [[#src_sp|'''sp''']] ''X'' ''Y'' ''Z'' ]

Line 1,596:

Line 2,922:

[ [[#src_sy|'''sy''']] ''YMIN'' ''YMAX'' ]

[ [[#src_sz|'''sz''']] ''ZMIN'' ''ZMAX'' ]

+

[ [[#src_srad|'''srad''']] ''RMIN'' ''RMAX'' ]

[ [[#src_ss|'''ss''']] ''SURF'' ]

[ [[#src_sd|'''sd''']] ''U'' ''V'' ''W'' ]

+

[ [[#src_sa|'''sa''']] ''PHI'' ]

[ [[#src_se|'''se''']] ''E'' ]

−

[ [[#src_sb|'''sb''']] ''N'' ''E1'' ''WGT1'' ''E2'' ''WGT2'' ... ]

+

[ [[#src_sb|'''sb''']] ''N'' ''INTT'' ''E1'' ''WGT1'' ''E2'' ''WGT2'' ... ]

[ [[#src_sr|'''sr''']] ''NUC'' ''MT'' ]

[ [[#src_st|'''st''']] ''TMIN'' ''TMIN'' ]

Line 1,605:

Line 2,933:

[ [[#src_si|'''si''']] ''N'' ''P1'' ''P2'' ... ]

[ [[#src_sg|'''sg''']] ''MAT'' ''MODE'' ]

−

Source definition. The first ~~parameter~~:

+

Source definition. The two first parameters:

{|

+

| <tt>''NAME''</tt>

+

|: source name

+

|-

| <tt>''PART''</tt>

| : particle type (n = neutron, p = photon)

|}

−

~~is optional in single particle simulations.~~ The remaining parameters are defined by separate key words followed by the input values.

+

The remaining parameters are defined by separate key words followed by the input values.

+

Notes:

+

*The particle type <tt>''PART''</tt> is optional in single particle simulations.

+

*A single source card may include one or several source types.

+

Source types:

Source weight (<tt>'''sw'''</tt>):

Line 1,636:

Line 2,973:

Notes:

*Setting a source cell is one of the options that can be applied to define the spatial distribution of source particles.

−

*The selection is based on rejection sampling, and if the source cell occupies a small volume of the geometry, the sampling efficiency can be increased by defining a bounding box around the cell using the <tt>''sx''</tt>, <tt>''sy''</tt> and <tt>''sz''</tt> options.

+

*The selection is based on rejection sampling, and if the source cell occupies a small volume of the geometry, the sampling efficiency can be increased by defining a bounding box/(vertical) cylinder around the cell (using the <tt>'''sx'''</tt>, <tt>'''sy'''</tt> and <tt>'''sz'''</tt> or <tt>'''sp'''</tt>, <tt>'''srad'''</tt> and <tt>'''sz'''</tt> options, respectively).

*If no spatial distribution is defined, particles are sampled uniformly over the geometry.

+

Source universe (<tt>'''su'''</tt>):

+

{|

+

| <tt>''UNI''</tt>

+

| : universe inside which the source points are sampled

+

|}

Line 1,649:

Line 2,994:

Notes:

*Setting a source material is one of the options that can be applied to define the spatial distribution of source particles.

−

*The selection is based on rejection sampling, and if the source material occupies a small volume of the geometry, the sampling efficiency can be increased by defining a bounding box around the ~~region~~ using the <tt>''sx''</tt>, <tt>''sy''</tt> and <tt>''sz''</tt> options.

+

*The selection is based on rejection sampling, and if the source material occupies a small volume of the geometry, the sampling efficiency can be increased by defining a bounding box/(vertical) cylinder around the cell (using the <tt>'''sx'''</tt>, <tt>'''sy'''</tt> and <tt>'''sz'''</tt> or <tt>'''sp'''</tt>, <tt>'''srad'''</tt> and <tt>'''sz'''</tt> options, respectively).

*If no spatial distribution is defined, particles are sampled uniformly over the geometry.

Line 1,657:

Line 3,002:

{|

| <tt>''X''</tt>, <tt>''Y''</tt>, <tt>''Z''</tt>,

−

| : coordinates of the source point

+

| : coordinates of the source point [in cm]

|}

Line 1,665:

Line 3,010:

−

Source boundaries (<tt>'''sx'''</tt>, <tt>'''sy'''</tt> ~~and~~ <tt>'''sz'''</tt>):

+

Source boundaries (<tt>'''sx'''</tt>, <tt>'''sy'''</tt>, <tt>'''sz'''</tt> and <tt>'''srad'''</tt>):

{|

| <tt>''XMIN''</tt>, <tt>''XMAX''</tt>

−

| : ~~Boundaries~~ on X-axis

+

| : boundaries on X-axis [in cm]

|-

| <tt>''YMIN''</tt>, <tt>''YMAX''</tt>

−

| : ~~Boundaries~~ on Y-axis

+

| : boundaries on Y-axis [in cm]

|-

| <tt>''ZMIN''</tt>, <tt>''ZMAX''</tt>

−

| : ~~Boundaries~~ on Z-axis

+

| : boundaries on Z-axis [in cm]

+

|-

+

| <tt>''RMIN''</tt>, <tt>''RMAX''</tt>

+

| : radial boundaries [in cm]

|-

|}

Notes:

−

*Source boundaries are used to define a bounding box inside which the source particles are sampled.

+

*Source boundaries are used to define a bounding box/(vertical) cylinder inside which the source particles are sampled.

+

*The radial boundaries are centered around the point defined by <tt>'''sp'''</tt> and can be used in combination with <tt>'''sz'''</tt>.

*Can be used in combination with cell and material sources to increase the sampling efficiency.

*If no bounding box is defined, particles are sampled uniformly over the geometry.

−

~~Surface source~~ (<tt>'''ss'''</tt>):

+

Source surface (<tt>'''ss'''</tt>):

{|

Line 1,694:

Line 3,043:

Notes:

*The surface source is currently limited to infinite vertical cylinder (<tt>'''cyl'''</tt>) and sphere (<tt>'''sph'''</tt>) surface types.

−

*~~Particles~~ are started in the direction of the ~~inward~~ surface normal.

+

*The default behavior is that particles are started in the direction of the outward surface normal.

+

*Positive and negative surface entries refer to neutrons being emitted in the direction of the positive and negative surface normal, respectively.

+

** Meaning: positive = outward, negative = inward - same convention as for the surface detectors.

Line 1,708:

Line 3,059:

*If no directional dependence is defined, the direction of source particles is sampled isotropically.

+

Source angular-aperture (<tt>'''sa'''</tt>):

+

{|

+

| <tt>''PHI''</tt>

+

| : polar angle [in degrees]

+

|}

+

Notes

+

*The source angular-aperture option can be set to define the semi-aperture with respect a direction.

+

*The option requires the definition of a unidirectional source (<tt>'''sd'''</tt>).

Source energy (<tt>'''se'''</tt>):

Line 1,713:

Line 3,075:

{|

| <tt>''E''</tt>

−

| : energy of source particles

+

| : energy of source particles [in MeV]

|}

Line 1,727:

Line 3,089:

| <tt>''N''</tt>

| : number of bins

+

|-

+

| <tt>''INTT''</tt>

+

| : interpolation (0 = line spectrum, 1 = histogram, 2 = lin-lin, 4 = log-lin)

|-

| <tt>''En''</tt>

−

| : upper boundary of the energy bin

+

| : upper boundary of the energy bin [in MeV]

|-

| <tt>''WGTn''</tt>

Line 1,738:

Line 3,103:

*This option allows defining an arbitrary source spectrum in the form of tabular data.

*The bins are entered in the order of ascending energy, and weight of the first bin must be set to zero.

−

*~~The interpolation between the bins~~ is ~~either linear (positive weight entries) or logarithmic (negative weight entries)~~.

+

*Interpolation is given in a separate parameter from version 2.1.31 on.

−

+

*Here, a simple test input that demonstrates the [[Source energy spectrum definition test case|source spectrum definition]].

Source reaction (<tt>'''sr'''</tt>):

Line 1,748:

Line 3,113:

|-

| <tt>''MT''</tt>

−

| : reaction number

+

| : reaction number identifier

|}

Line 1,762:

Line 3,127:

{|

| <tt>''TMIN''</tt>, <tt>''TMAX''</tt>

−

| : time boundaries

+

| : time boundaries [in s]

|}

Line 1,781:

Line 3,146:

Notes:

−

*Source files allow defining arbitrary distributions by reading the particle coordinates, direction, energy, weight and time from a file.

+

*Source files allow defining arbitrary distributions by reading the particle coordinates, direction, energy, weight and time from a file: [<tt> x y z u v w E wgt t </tt>] .

−

*Source files can be produced using the <tt>'''df'''</tt> entry of [[#det_df|detector cards]] or the [[#set csw|set csw]] ~~option~~.

+

*Source files can be produced using the <tt>'''df'''</tt> entry of [[#det_df|detector cards]], or the [[#set csw|set csw]] or [[#set gsw|set gsw]] options.

Line 1,806:

Line 3,171:

{|

| <tt>''MAT''</tt>

−

| : material name ~~or -1~~

+

| : material name

|-

| <tt>''MODE''</tt>

Line 1,813:

Line 3,178:

Notes:

−

*Radioactive decay source combines material compositions to decay data read from ENDF format libraries and forms the normalized source distribution automatically.

+

*Radioactive decay source combines material compositions to decay data read from ENDF format<ref name="endf" /> libraries and forms the normalized source distribution automatically.

−

*Material compositions can be defined manually, or read from binary restart files produced by a burnup or activation calculation (see the [[#set rfw|set rfw]] and [[#set rfr|set rfr]] options).

+

*Radioactive material:

−

*~~If the material name~~ is ~~replaced by~~ -1~~, source points are started from~~ all radioactive materials.

+

**Material compositions can be defined manually, or read from binary restart files produced by a burnup or activation calculation (see the [[#set rfw|set rfw]] and [[#set rfr|set rfr]] options).

−

*The analog sampling mode preserves the average number of particles produced in radioactive decay, but may lead to poor sampling efficiency in geometries with both low and high-active materials.

+

**There is a special entry for the <tt>''MAT''</tt> parameter:

−

*The implicit sampling mode preserves the total statistical weight of emitted particles and produces a uniform source distribution over activated materials.

+

***"<tt>-1</tt>": to refer to all radioactive materials in the calculation system

−

*In version 2.1.28 ~~the source~~ is limited to photon line spectra.

+

*Sampling mode:

−

*The calculation produces an additional output file <tt>[input]_gsrc.m</tt> that contains the source spectra.

+

**The analog sampling mode preserves the average number of particles produced in radioactive decay, but may lead to poor sampling efficiency in geometries with both low and high-active materials.

+

**The implicit sampling mode preserves the total statistical weight of emitted particles and produces a uniform source distribution over activated materials.

+

*The radiation types included are discrete line and continuum spectra for photon and neutron reactions.

+

**The radioactive decay source in version 2.1.28 and earlier is limited to photon line spectra.

+

*The calculation produces an additional output file <tt>[input]_gsrc.m</tt> or <tt>[input]_nsrc.m</tt> that contains the gamma/neutron source spectra, respectively.

*See [[Radioactive decay source, practical example|practical example]] for more information.

=== strans (surface transformation) ===

−

See [[#trans (transformations)|transformations]].

+

Defines surface transformations. Shortcut for "<tt>trans s</tt>".

+

Notes:

+

*The parameters associated with the transformation follow the standard transformation cards syntax without '''trans''' <tt>''TYPE''</tt> identifier.

+

*See [[#trans (transformations)|transformations]].

=== surf (surface definition) ===

Line 1,859:

Line 3,232:

'''thermstoch''' ''NAME'' ''TEMP'' ''LIB1'' ''LIB2''

−

Defines thermal scattering data that can be linked to nuclides using input entry '''moder''' in the [[#mat (material definition)|material cards]]. When using thermal scattering data together with TMS on-the-fly temperature treatment, the third input value of the therm card is 0. In this case, Serpent interpolates the thermal scattering data automatically to the local temperature, as defined either using the '''tms''' input entry in the material definition or via the multi-physics interface.

+

Defines thermal scattering data that can be linked to nuclides using input entry '''moder''' in the [[#mat (material definition)|material cards]]. Input values:

−

~~Input values:~~

{|

| <tt>''NAME''</tt>

Line 1,870:

Line 3,242:

|-

| <tt>''TEMP''</tt>

−

| : temperature to which the thermal scattering data is interpolated

+

| : temperature to which the thermal scattering data is interpolated [in K]

|}

Notes:

−

+

* On-the-fly thermal motion sampling (TMS) temperature treatment:

−

*~~When using on~~-the-fly ~~interpolation~~ of thermal scattering data, <tt>''LIBi''</tt> must cover the whole ~~temperature~~ range in which the materials appear in the geometry~~. I~~.e. ~~extrapolation of the~~ data is not supported.

+

**It requires the third value of the therm card to be set to "<tt>0</tt>"

−

*Thermal scattering data is interpolated using the methodology of makxsf code

+

**The thermal scattering data is automatically interpolated to the local temperature.

−

*~~The~~ interpolation can be performed using the stochastic mixing approach with '''thermstoch'''. This interpolation mode is ~~not~~ available ~~for~~ on-the-fly ~~interpolation~~.

+

**The local temperature is either defined using:

+

*** the '''tms''' entry in the material card (see [[#mat|mat card]])

+

*** the multi-physics interface (see [[#ifc|ifc card]]), where the temperature limits are defined using the '''tft''' entry in the material card (see [[#mat|mat card]])

+

**The thermal scattering libraries <tt>''LIBi''</tt> must cover the whole range in which the materials appear in the geometry, i.e. data extrapolation is not supported.

+

*Interpolation:

+

**Thermal scattering data is interpolated using the methodology of makxsf code<ref name="makxsf">Brown, F. B. ''"The makxsf Code with Doppler Broadening"'', Los Alamos National Laboratory Tech. Rep., LA-UR-06-7002, Los Alamos, NM, [https://mcnp.lanl.gov/pdf_files/TechReport_2006_LANL_LA-UR-06-7002_Brown.pdf 2006]</ref>.

+

**Alternatively, the interpolation can be performed using the stochastic mixing approach with the '''thermstoch''' entry.

+

***This interpolation mode doesn't support on-the-fly interpolation.

+

*The continuous S(α, β) formalism:

+

**It is available from version 2.1.32 on.

+

**The on-the-fly temperature treatment is available from version 2.2.0 and on.

=== tme (time binning definition) ===

Line 1,897:

Line 3,279:

|-

| <tt>''LIMn''</tt>

−

| : time bin boundaries in arbitrary binning

+

| : time bin boundaries in arbitrary binning [in s]

|-

| <tt>''Tmin''</tt>

−

| : minimum time boundary in uniform or log-uniform binning

+

| : minimum time boundary in uniform or log-uniform binning [in s]

|-

| <tt>''Tmax''</tt>

−

| : maximum time boundary in uniform or log-uniform binning

+

| : maximum time boundary in uniform or log-uniform binning [in s]

|}

Notes:

−

*The entered values are in seconds

*The first limit in the arbitrary type (type = 1), is the lower bound of the first bin. The second limit is the upper bound of the first bin and so on.

*Time binning is used with [[#det (detector definition)|detectors]] and [[Dynamic external source simulation mode|dynamic simulation mode]].

Line 1,914:

Line 3,295:

=== trans (transformations) ===

−

'''trans''' ''TYPE'' ''UNIT'' ''LVL''

+

'''trans''' ''TYPE'' ''UNIT'' [ ''IDX'' ] ''LVL''

−

'''trans''' ''TYPE'' ''UNIT'' ''X'' ''Y'' ''Z''

+

'''trans''' ''TYPE'' ''UNIT'' [ ''IDX'' ] ''X'' ''Y'' ''Z''

−

'''trans''' ''TYPE'' ''UNIT'' ''X'' ''Y'' ''Z'' ''θx'' ''θy'' ''θz'' ''ORD''

+

'''trans''' ''TYPE'' ''UNIT'' [ ''IDX'' ] ''X'' ''Y'' ''Z'' ''θx'' ''θy'' ''θz'' ''ORD''

−

'''trans''' ''TYPE'' ''UNIT'' ''X'' ''Y'' ''Z'' ''α1'' ''α2'' ''α3'' ''α4'' ''α5'' ''α6'' ''α7'' ''α8'' ''α9'' ''ORD''

+

'''trans''' ''TYPE'' ''UNIT'' [ ''IDX'' ] ''X'' ''Y'' ''Z'' ''α1'' ''α2'' ''α3'' ''α4'' ''α5'' ''α6'' ''α7'' ''α8'' ''α9'' ''ORD''

−

'''trans''' ''TYPE'' ''UNIT'' '''rot''' ''X0'' ''Y0'' ''Z0'' ''I'' ''J'' ''K'' ''β''

+

'''trans''' ''TYPE'' ''UNIT'' [ ''IDX'' ] '''rot''' ''X0'' ''Y0'' ''Z0'' ''I'' ''J'' ''K'' ''β''

−

Defines surface, universe or fill transformation. Input values:

+

Defines surface, universe, fill, lattice, detector mesh or source transformation. Input values:

{|

| <tt>''TYPE''</tt>

−

| : type of transformation (S = surface ~~transformation~~, F = fill ~~transformation~~, U = universe ~~transformation~~)

+

| : type of transformation (S = surface, F = fill, U = universe, L = lattice, D = detector mesh, SR = source)

|-

| <tt>''UNIT''</tt>

−

| : surface, cell or universe name to which the transformation is applied

+

| : surface, cell, universe, lattice, detector mesh or source name to which the transformation is applied

+

|-

+

| <tt>''IDX''</tt>

+

| : index number of lattice position to which the lattice transformation (type L) is applied

|-

| <tt>''LVL''</tt>

Line 1,937:

Line 3,321:

|-

| <tt>''X'',''Y'',''Z''</tt>

−

| : translation vector

+

| : translation vector [in cm]

|-

| <tt>''θx'' ''θy'' ''θz''</tt>

−

| : rotation angles with respect to x-, y- and z-axes (in degrees)

+

| : rotation angles with respect to x-, y- and z-axes [in degrees]

|-

| <tt>''α1'' ... ''α9''</tt>

Line 1,949:

Line 3,333:

|-

| <tt>''X0'',''Y0'',''Z0''</tt>

−

| : ~~Origin~~ of vector defining rotation axis.

+

| : origin of vector defining rotation axis [in cm]

|-

| <tt>''I'',''J'',''K''</tt>

−

| : ~~Components~~ of vector defining rotation axis.

+

| : components of vector defining rotation axis.

|-

| <tt>''β''</tt>

−

| : ~~Angle~~ around rotation axis defined by a vector (in degrees). '''NB: ~~In Serpent 2~~.~~1.29 positive values correspond~~ to ~~rotation~~ to the ~~negative mathematical direction and vice versa~~.'''

+

| : angle around rotation axis defined by a vector [in degrees].

+

|-

+

|}

+

The possible transformation types are:

+

::{| class="wikitable" style="text-align: left;"

+

! Type

+

! Description

+

! Notes

+

|-

+

| <tt>s</tt>

+

| surface

+

|

+

|-

+

| <tt>f</tt>

+

| fill

+

| It is applied in the universe filling the given cell.

+

|-

+

| <tt>u</tt>

+

| universe

+

| ''Special type'': level transformation, in which the coordinates in the given universe are obtained relative to geometry level <tt>''LVL''</tt>.

+

|-

+

| <tt>l</tt>

+

| lattice

+

| It requires to provide the index number <tt>''IDX''</tt> of lattice position to which the transformation is applied.

+

|-

+

| <tt>d</tt>

+

| mesh detector

+

| It is associated to mesh detectors (such as '''dx''', '''dy''', '''dz''', '''dh''', '''dn''' or '''dmesh''', see [[#det|det card]])

+

|-

+

| <tt>sr</tt>

+

| source

+

| It is inverted compared to how surface, universe, etc. are handled

|-

|}

Notes:

+

*Translations: by providing the translation vector.

+

**By default translations are applied before rotations, and the order can be switched using the <tt>''ORD''</tt> parameter.

+

*Rotations:

+

**With respect x-/y-/z-axes: either by providing the three angles with respect to the three coordinate axes, or by defining the rotation matrix.

+

***In the second case Serpent applies vector multiplication: <math>\vec{r'} = \bold{A} \vec{r}</math>

+

:::where <math>\vec{r}</math> and <math>\vec{r'}</math> are the position vectors before and after the operation and coefficients <tt>''α1'' ... ''α9''</tt> define the 3 by 3 matrix <math>\bold{A}</math>.

+

:*With respect a general axes: using the '''rot''' keyword and associated syntax.

+

:**In Serpent 2.1.29, a positive value of ''β'' corresponds to rotation to the negative mathematical direction and vice versa.

+

*Backwards compatibility:

+

**To preserve backwards compatibility, input parameters "<tt>strans</tt>", "<tt>utrans</tt>", "<tt>ftrans</tt>" and "<tt>dtrans</tt>" without the following type identifier are also accepted for defining surface, universe, fill and detector mesh transformations, respectively.

+

**To preserve compatibility with Serpent 1, parameter "<tt>trans</tt>" without type identifier defines a universe transformation.

−

*Fill transformation ~~is applied in the universe filling the given cell.~~

+

=== transb (burnup transformation) ===

−

*Level transformation is a special type of universe transformation, in which the coordinates in the given universe are obtained relative to geometry level <tt>~~''LVL''~~</tt>.

+

−

*By default translations are applied before rotations, and the order can be switched using the <tt>''ORD''</tt> parameter.

+

−

*Rotations can be defined either by providing the three angles with respect to the three coordinate axes, or by defining the rotation matrix. In the second case Serpent applies vector multiplication <math>\vec{r'} = \bold{A} \vec{r}</math> where <math>\vec{r}</math> and <math>\vec{r'}</math> are the position vectors before and after the operation and coefficients <tt>''α1'' ... ''α9''</tt> define the 3 by 3 matrix <math>\bold{A}</math>.

+

−

*To preserve backwards compatibility, input parameters "strans", "utrans" and "ftrans" without the following type identifier are also accepted for defining surface, universe and fill transformations, respectively. To preserve compatibility with Serpent 1, parameter "trans" without type identifier defines a universe transformation.

+

−

~~=== transv and transa (velocity and acceleration transformations)~~<~~span id="transa"~~>~~ ===~~

+

'''transb''' ''STEP'' [ <''trans''> ]

−

~~'''transv''' ''TYPE'' ''UNIT'' [ '''tlim''' ''T0'' ''T1'' ''TTYPE'' ] ''VX'' ''VY'' ''VZ''~~

+

Defines burnup-dependent surface, universe, fill, lattice, detector mesh or source transformation. Input values:

−

'''transa''' ''TYPE'' ''UNIT'' [ '''tlim''' ''T0'' ''T1'' ''TTYPE'' ] ''AX'' ''AY'' ''AZ''

+

{|

+

| <tt>''STEP''</tt>

+

| : depletion step (positive value = burnup [in MWd/kg], negative value = time [in d])

+

|-

+

| <tt><''trans''></tt>

+

| : list of parameters associated with the transformation

+

|}

+

Notes:

+

*The parameters associated with the transformation follow the standard transformation cards syntax without '''trans''' identifier.

+

*Standard properties applicable to regular or non-time dependent transformations apply.

+

*For more information, see detailed description on transformations ([[#trans (transformations)|trans card]]).

+

*Geometry plots associated with burnup transformations are featured from version 2.2.1 and on.

+

=== transv and transa (velocity and acceleration transformations) ===

+

'''transv''' ''TYPE'' ''UNIT'' [ ''IDX'' ] [ '''tlim''' ''T0'' ''T1'' ''TTYPE'' ] ''VX'' ''VY'' ''VZ''

+

'''transa''' ''TYPE'' ''UNIT'' [ ''IDX'' ] [ '''tlim''' ''T0'' ''T1'' ''TTYPE'' ] ''AX'' ''AY'' ''AZ''

−

Defines surface, universe or fill transformation. Input values:

+

Defines a time-dependent surface, universe, fill, lattice, detector mesh or source transformation. Input values:

{|

| <tt>''TYPE''</tt>

−

| : type of transformation (S = surface ~~transformation~~, F = fill ~~transformation~~, U = universe ~~transformation~~)

+

| : type of transformation (S = surface, F = fill, U = universe, L = lattice, D = detector mesh, SR = source)

|-

| <tt>''UNIT''</tt>

−

| : surface, cell or universe name to which the transformation is applied

+

| : surface, cell, universe, lattice, detector mesh or source name to which the transformation is applied

+

|-

+

| <tt>''IDX''</tt>

+

| : index number of lattice position to which the lattice transformation (type L) is applied

|-

| <tt>''T0''</tt>

−

| : beginning time of the transformation

+

| : beginning time of the transformation [in s]

|-

| <tt>''T1''</tt>

−

| : end time of the transformation

+

| : end time of the transformation [in s]

|-

| <tt>''TTYPE''</tt>

Line 1,993:

Line 3,436:

|-

| <tt>''VX'',''VY'',''VZ''</tt>

−

| : ~~Initial~~ velocity vector

+

| : initial velocity vector [in cm/s]

|-

| <tt>''AX'',''AY'',''AZ''</tt>

−

| : ~~Initial~~ acceleration vector

+

| : initial acceleration vector [in cm/s2]

|}

Notes:

−

*~~Fill transformation is applied in the universe filling the given cell~~.

+

*Standard properties applicable to regular or non-time dependent transformations apply.

*The transformation is updated at the simulation time-interval boundaries.

−

*See [[UGM 2016 Moving geometry]].

+

** The time-dependent transformation evaluation method option is defined by the [[#set_transtime|set transtime]] option.

−

*See [[Rotating Translating STL Bunny]].

+

*For practical examples:

+

**See [[UGM 2016 Moving geometry]].

+

**See [[Rotating Translating STL Bunny]].

+

===umsh (unstructured mesh-based geometry definition) ===

+

''UNI'' ''BGUNI''

+

''MESH_SPLIT'' ''MESH_DIM'' ''SZ1'' ''SZ2'' ... ''SZMESH_DIM''

+

''POINTS_FILE''

+

''FACES_FILE''

+

''OWNER_FILE''

+

''NEIGHBOUR_FILE''

+

''MATERIALS_FILE''

+

Defines an unstructured mesh-based geometry. Input values:

+

{|

+

| <tt>''UNI''</tt>

+

| : universe name for the unstructured mesh-based geometry

+

|-

+

| <tt>''BGUNI''</tt>

+

| : name of the background universe filling all undefined space

+

|-

+

| <tt>''MESH_SPLIT''</tt>

+

| : splitting criterion for the adaptive search mesh (maximum number of geometry cells in search mesh cell)

+

|-

+

| <tt>''MESH_DIM''</tt>

+

| : number of levels in the adaptive search mesh

+

|-

+

| <tt>''SZi''</tt>

+

| : size of the search mesh at level <tt>''i''</tt>

+

|-

+

| <tt>''POINTS_FILE''</tt>

+

| : path to the unstructured mesh points file

+

|-

+

| <tt>''FACES_FILE''</tt>

+

| : path to the unstructured mesh faces file

+

|-

+

| <tt>''OWNER_FILE''</tt>

+

| : path to the unstructured mesh owner file

+

|-

+

| <tt>''NEIGHBOUR_FILE''</tt>

+

| : path to the unstructured mesh neighbour file

+

|-

+

| <tt>''MATERIALS_FILE''</tt>

+

| : path to the unstructured mesh materials file

+

|}

+

Notes:

+

*For more information, see the description of the '''solid''' description of how to create a 3D unstructured mesh-based universe geometry ([[#solid|solid card]], type 1).

=== utrans (universe transformation) ===

−

See [[#trans (transformations)|transformations]].

+

Defines universe transformations. Shortcut for "<tt>trans u</tt>".

+

Notes:

+

*The parameters associated with the transformation follow the standard transformation cards syntax without '''trans''' <tt>''TYPE''</tt> identifier.

+

*See [[#trans (transformations)|transformations]].

+

=== voro (stochastic Voronoi tessellation geometry definition) ===

+

'''voro''' ''UNI0'' ''UNIbg'' ''R0'' '''-1''' ''NP'' ''UNI1'' ''VF1'' [ ''UNI2'' ''VF2'' ... ]

+

'''voro''' ''UNI0'' ''UNIbg'' ''R0'' ''FILE''

+

Defines a stochastic Voronoi tessellation geometry. Input values:

+

{|

+

| <tt>''UNI0''</tt>

+

|: universe name for the Voronoi medium

+

|-

+

| <tt>''UNIbg''</tt>

+

|: background universe name filling all undefined space

+

|-

+

| <tt>''R0''</tt>

+

|: test radius [in cm]

+

|-

+

| <tt>''NP''</tt>

+

|: number of seed points

+

|-

+

| <tt>''UNIm''</tt>

+

|: sub-universe name for the ''m''-th random fragmented polyhedral zone

+

|-

+

| <tt>''VFm''</tt>

+

|: volume fraction associated to ''m''-th random fragmented polyhedral zone

+

|-

+

| <tt>''FILE''</tt>

+

|: input file containing the Voronoi data

+

|}

+

The syntax of the file containing the Voronoi seed points data is:

+

::{| class="toccolours" style="text-align: left;"

+

|-

+

| ''X1'' ''Y1'' ''Z1'' ''UNI1''

+

|-

+

| ''X2'' ''Y2'' ''Z2'' ''UNI1''

+

|-

+

| ...

+

|-

+

| ''XN'' ''YN'' ''ZN'' ''UNI1''

+

|-

+

| ''XN+1'' ''YN+1'' ''ZN+1'' ''UNI2''

+

|-

+

| ...

+

|}

+

where:

+

{|

+

| <tt>''Xn'', ''Yn'', ''Zn''</tt>

+

|: seed points coordinates [in cm]

+

|-

+

| <tt>''UNIm''</tt>

+

|: sub-universe name for the ''m''-th random zone associated to the given seed point

+

|}

+

Notes:

+

*The input consists of a list of seed points and associated sub-universes filling the Voronoi cells Alternatively, the number of seeds points and volume fractions of each zone can be provided, letting Serpent sample the positions randomly.

+

**The advantage of the first option is that the distribution can be defined explicitly, taking into account, for example, the varying level of fragmentation closer to the boundaries.

+

*The cell search and surfaces distances are based on search mesh and local short-list of points to reduce the computational effort.

+

**The search mesh is conditioned by the test radius, which should enclose the Voronoi polyhedral cells.

+

***Too small radius may result in geometry errors as some points are excluded from all the search mesh cells in which they should be.

+

***Too large radius may results in including points in cells that do not actually intersect with the polyhedral boundary.

+

*The <tt>''DENS''</tt> parameter in the [[#set mcvol|mcvol]] input option can be switched "<tt>on</tt>" to compensate the non-preservation of the volume fractions provided as input due to the randomness of the seed points.

+

**It applies calculated scaling factors to material densities preserving the original masses (scaling factor = volume MC routine / volume given)

=== wwgen (response matrix based importance map solver) ===

Line 2,016:

Line 3,579:

''MIN2'' ''MAX2'' ''SZ2''

''MIN3'' ''MAX3'' ''SZ3''

−

''DET1'' ''w1'' [ ''DET2'' ''w2'' ... ]

+

''DET1'' ''W1'' [ ''DET2'' ''W2'' ... ]

'''wwgen''' ''NAME'' ''LIM'' ''NI'' ''MOD'' ''ERG'' ''MSH''

Line 2,023:

Line 3,586:

''LIM21'' ''LIM22'' ...

''LIM31'' ''LIM32'' ...

−

''DET1'' ''w1'' [ ''DET2'' ''w2'' ... ]

+

''DET1'' ''W1'' [ ''DET2'' ''W2'' ... ]

+

'''wwgen''' ''NAME'' ''LIM'' ''NI'' ''MOD'' ''ERG'' ''MSH''

+

''X0'' ''Y0''

+

''P'' ''NX'' ''NY''

+

''MIN3'' ''MAX3'' ''SZ3''

+

''DET1'' ''W1'' [ ''DET2'' ''W2'' ... ]

Defines the parameters for importance map calculation. Input values:

Line 2,039:

Line 3,607:

|-

| <tt>''MOD''</tt>

−

| : solution mode (~~use~~ 1 ~~for now~~)

+

| : solution mode (1 = single detector, 2 = multiple detectors, 3 = global variance reduction)

|-

| <tt>''ERG''</tt>

Line 2,045:

Line 3,613:

|-

| <tt>''MSH''</tt>

−

| : mesh type (1 = Cartesian, 2 = Cylindrical, 6 = unevenly-spaced xyz, 8 = unevenly spaced cylindrical)

+

| : mesh type (1 = Cartesian, 2 = Cylindrical, 4 = x-type hexagonal, 5 = y-type hexagonal, 6 = unevenly-spaced xyz, 8 = unevenly spaced cylindrical)

|-

| <tt>''MINn''</tt>

−

| : minimum mesh boundary (n:th coordinate)

+

| : minimum mesh boundary (''n''-th coordinate)

|-

| <tt>''MAXn''</tt>

−

| : maximum mesh boundary (n:th coordinate)

+

| : maximum mesh boundary (''n''-th coordinate)

|-

| <tt>''SZn''</tt>

−

| : number of mesh cells (n:th coordinate)

+

| : number of mesh cells (''n''-th coordinate)

|-

| <tt>''LIMnm''</tt>

−

| : m:th ~~boundary of~~ n:th coordinate)

+

| : mesh boundary ''m''-th (''n''-th coordinate)

+

|-

+

| <tt>''X0'', ''Y0''</tt>

+

| : mesh center of hexagonal mesh (currently must be centered at the origin)

+

|-

+

| <tt>''P''</tt>

+

| : hexagonal cell pitch

+

|-

+

| <tt>''NX'', ''NY''</tt>

+

| : hexagonal mesh size

|-

| <tt>''DETi''</tt>

| : detectors used as target response functions

|-

−

| <tt>''wi''</tt>

+

| <tt>''Wi''</tt>

| : weight factors for detector scores

|}

Line 2,068:

Line 3,645:

Notes:

−

*The solution mode provides various options on how the responses are used for calculating the importances. ~~For now, only~~ mode ~~1 is supported~~ (~~calculate importances directly with respect~~ to the ~~response)~~.

+

*The solution mode provides various options on how the responses are used for calculating the importances.

+

*The detector entries can be left out in global variance reduction mode (<tt>''MOD''</tt> = 3), in which case the mesh is optimized to uniformly populate the entire geometry.

*Cartesian and cylindrical mesh are defined by outer mesh boundaries and number of mesh cells.

*Unevenly-spaced meshes are defined by providing the mesh cell boundaries separately.

*The coordinate axes 1, 2 and 3 in Cartesian mesh refer to (x,y,z) and in cylindrical mesh to (r,θ,z), with θ given in degrees.

+

*The hexagonal mesh is defined by mesh center, cell pitch, number of cells in the radial dimensions (similar to the hexagonal lattice) and axial binning.

*The mesh must be defined slightly larger than the geometry (the mesh boundaries should not coincide with the geometry boundaries).

*Source points located on mesh cell boundaries cause fatal errors.

Line 2,077:

Line 3,656:

*The importance mesh is printed in file <tt>[input].wwd</tt>.

*Importance (weight window) meshes are read using the [[#wwin (weight window mesh definition)|wwin card]].

−

*~~This capability is still very much under development. The input syntax may be revised at some point~~.

+

*See also practical examples on [[Variance reduction]].

=== wwin (weight window mesh definition) ===

'''wwin''' ''NAME''

−

[ '''wf''' ''FILE'' ''FMT'' ''SB'' ''TYPE'' ]

+

[ [[#wwin_wf|'''wf''']] ''FILE'' ''FMT'' ]

−

[ '''wn''' ''F'' ''X'' ''Y'' ''Z'' ''E'' ]

+

[ [[#wwin_wn|'''wn''']] ''F'' ''X'' ''Y'' ''Z'' ''E'' ]

−

[ '''wx''' ''C'' ''G'' ]

+

[ [[#wwin_wx|'''wx''']] ''C'' ''G'' ]

+

[ [[#wwin_wt|'''wt''']] ''SB'' ''TYPE'' ''MIN'' ''MAX'' ]

+

[ [[#wwin_wi1|'''wi''']] ''ITP'' ''NI'' ''WWG1'' ''DF1'' ''WWG2'' ''DF2'' ... ]

+

[ [[#wwin_wi2|'''wi''']] ''ITP'' ''NI'' ''WWG'' ''NX'' ''NY'' ''NZ'' ''NLOOP'' ''NTRK'' ''ISPL'' ''NSPL'' ''DSPL1'' ''SX1'' ''SY1'' ''SZ1'' ''DSPL2'' ''SX2'' ''SY2'' ''SZ2'' ...]

−

Defines a weight window mesh for variance reduction. ~~Input values~~:

+

Defines a weight window mesh for variance reduction. The first parameter:

{|

| <tt>''NAME''</tt>

| : a unique name to identify the mesh

−

|-

+

|}

+

The remaining parameters are defined by separate key words followed by the input values.

+

Notes:

+

*Only works in external source simulation mode.

+

*Importance (weight window) meshes can be generated by running the [[#wwgen (response matrix based importance map solver)|response matrix based solver]], or read in MCNP WWINP format<ref>Kulesza, J. A. (ed.), ''“MCNP code version 6.3.0 Theory & User Manual: Appendix A Mesh-Based WWINP, WWOUT, and WWONE File Format,”'' LA-UR-22-30006, Rev. 1, Los Alamos National Laboratory [https://mcnp.lanl.gov/pdf_files/TechReport_2022_LANL_LA-UR-22-30006Rev.1_KuleszaAdamsEtAl.pdf (2022)].</ref>.

+

*Importance maps can be visualized using the [[#plot (geometry plot definition)|geometry plotter]].

+

*See also [[#set wwb|set wwb]] and [[#set maxsplit|set maxsplit]] for setting options for weight windows, splitting and Russian roulette.

+

*See also practical examples on [[Variance reduction]].

+

Weight-window mesh paramters:

+

Mesh file (<tt>'''wf'''</tt>):

+

{|

| <tt>''FILE''</tt>

| : file path and name of the importance mesh file

|-

| <tt>''FMT''</tt>

−

| : file format (1 = mesh produced by Serpent importance map generator, 2 = MCNP weight window mesh file)

+

| : file format (1 = mesh produced by Serpent importance map generator, 2 = MCNP WWINP format weight window mesh file)

−

|-

+

|}

−

| <tt>~~''SB''~~</tt>

+

−

~~| : option to set source biasing on~~ (~~1/yes) or off (0/~~no) ~~with Serpent-generated importance maps~~

+

Notes:

−

|-

+

−

| <tt>''~~TYPE~~''</tt>

+

*By default the importance map is read from the mesh file and used as-is, the additional options are provided for adjustments.

−

| : ~~unused type parameter for Serpent-generated importance maps (set to 2)~~

+

*Currently the MCNP format only supports simple mesh types (no sub-mesh).

−

|-

+

Mesh normalization (<tt>'''wn'''</tt>):

+

{|

| <tt>''F''</tt>

| : importance for renormalization

Line 2,111:

Line 3,714:

|-

| <tt>''E''</tt>

−

| : energy used for renormalization

+

| : energy used for renormalization [in MeV]

−

|-

+

|}

+

Notes:

+

*The importances can be renormalized by fixing the value at a given position and energy.

+

Mesh adjustment (<tt>'''wx'''</tt>):

+

{|

| <tt>''C''</tt>

| : constant multiplier for adjusting importances

Line 2,122:

Line 3,734:

Notes:

−

*By default the importance map is read from the mesh file and used as-is, the additional options are provided for adjustments.

+

*The importances can be adjusted by constant multiplier <tt>''C''</tt> and exponential factor <tt>''G''</tt> such that <math>F' = CF^G</math>.

−

*The importances can be renormalized using the '''wn''' option by fixing the value at a given position and energy.

+

−

*The importances can be adjusted ~~using the '''wx''' option~~ by constant multiplier <tt>''C''</tt> and exponential factor <tt>''G''</tt> such that <math>F' = CF^G</math>.

+

−

*Currently the MCNP format only supports regular mesh type (uniform spacing).

+

−

*Only works in external source simulation mode.

+

−

*Source biasing works only for limited source types.

+

−

*Importance (weight window) meshes can be generated by running the [[#wwgen (response matrix based importance map solver)|response matrix based solver]].

+

−

*Importance maps can be visualized using the [[#plot (geometry plot definition)|geometry plotter]].

+

−

*This capability is still very much under development. The input syntax may be revised at some point.

+

−

== Input options ==

+

Types and options (<tt>'''wt'''</tt>):

+

{|

+

| <tt>''SB''</tt>

+

| : option to set source biasing on (1/yes) or off (0/no) with Serpent-generated importance maps

+

|-

+

| <tt>''TYPE''</tt>

+

| : bounds type for Serpent-generated weight-windows (1 = averaged, 2 = segment-wise)

+

|-

+

| <tt>''MIN''</tt>

+

| : minimum truncation limit for importances

+

|-

+

| <tt>''MAX''</tt>

+

| : maximum truncation limit for importances

+

|}

+

Notes:

+

*Source biasing is currently not available

+

Weight-window iterations, fixed mesh (<tt>'''wi'''</tt>):

+

{|

+

| <tt>''ITP''</tt>

+

| : iteration type (1 = fixed mesh)

+

|-

+

| <tt>''NI''</tt>

+

| : number of iterations between Monte Carlo simulation and the response matrix solver

+

|-

+

| <tt>''WWGi''</tt>

+

| : name of the WWG-structure used in the iteration

+

|-

+

| <tt>''DFi''</tt>

+

| : global density factor

+

|}

+

Notes:

+

*The fixed mesh option (<tt>''ITP''</tt> = 1) allows performing iterations using a single or multiple meshes generated using the [[#wwgen (response matrix based importance map solver)|response matrix based solver]].

+

*The global density factor is a multiplier applied to all material densities.

+

Weight-window iterations, adaptive mesh (<tt>'''wi'''</tt>):

+

{|

+

| <tt>''ITP''</tt>

+

| : iteration type (2 = geometry-based adaptation, 3 = tracking-based adaptation)

+

|-

+

| <tt>''NI''</tt>

+

| : number of iterations between Monte Carlo simulation and the response matrix solver

+

|-

+

| <tt>''WWG''</tt>

+

| : name of the WWG-structure used in the iteration

+

|-

+

| <tt>''NX''</tt>

+

| : number of x-divisions for the adaptive mesh

+

|-

+

| <tt>''NY''</tt>

+

| : number of y-divisions for the adaptive mesh

+

|-

+

| <tt>''NZ''</tt>

+

| : number of z-divisions for the adaptive mesh

+

|-

+

| <tt>''NLOOP''</tt>

+

| : number of outer iteration loops in generation of adaptive mesh

+

|-

+

| <tt>''NTRK''</tt>

+

| : number of tracks per loop in generation of adaptive mesh

+

|-

+

| <tt>''ISPL''</tt>

+

| : importance split criterion

+

|-

+

| <tt>''NSPL''</tt>

+

| : neighbor split criterion

+

|-

+

| <tt>''DSPLi''</tt>

+

| : density split criterion (positive value = atomic density [in b-1cm-1], negative values = mass density [in g/cm3])

+

|-

+

| <tt>''SZi''</tt>

+

| : minimum cell dimension [in cm]

+

|}

+

Notes:

+

*The adaptive mesh option (<tt>''ITP''</tt> = 2 or 3) starts with a coarse base mesh, and refines the resolution iteratively.

+

*There are two adaptive mesh options:

+

**In the geometry-based option (<tt>''ITP''</tt> = 2) Serpent covers the geometry with <tt>''NTRK''</tt> random tracks and splits cells according to density criteria.

+

**In the tracking-based option (<tt>''ITP''</tt> = 3) the tracks are started from the source instead. The procedure is repeated <tt>''NLOOP''</tt> times.

+

*Cell splitting is defined using the <tt>''NX'', ''NY''</tt> and <tt>''NZ''</tt> options.

+

**For example <tt>''NX''</tt> = 2, <tt>''NY''</tt> = 2, <tt>''NZ''</tt> = 2 results in each cell being split to 8 sub-cells (octree mesh).

+

**For 2D meshes the <tt>''NZ''</tt> parameter must be set to "1".

+

*Splitting is carried out recursively, until limiting criteria are met.

+

**The importance split criterion defines the maximum relative difference between the importances of two adjacent cells.

+

***If the criterion is not met, both cells are split.

+

**The neighbor split criterion defines the maximum number of neighbor allowed for a cell.

+

***If the criterion is not met, the cell is split.

+

**The <tt>''DSPL''</tt> and <tt>''SZi''</tt> parameters define upper density boundaries and minimum cell sizes for stopping the splits.

+

== Input options ==

Input options are used to set various calculation parameters that are not included in the main input cards. Each option is identified by key word "set". Optional values are enclosed within square brackets.

+

=== set absrate ===

+

'''set absrate''' ''A'' [ ''MAT'' ]

+

Sets normalization to total absorption rate. Input values:

+

{|

+

| <tt>''F''</tt>

+

| : number of neutrons absorbed per second [in neutrons/s]

+

|-

+

| <tt>''MAT''</tt>

+

| : dummy parameter

+

|}

+

Notes:

+

*Normalization is needed to relate the Monte Carlo reaction rate estimates to a user-given parameter.

+

*Absorption includes all reactions in which the incident neutron is lost, i.e. all capture reactions and fission.

+

*The default normalization:

+

**It is set to unit total loss rate (neutron transport) and to unit total source rate (photon transport).

+

**In coupled neutron-photon transport simulations the normalization is driven by the neutron normalization.

+

+

*See also Section 5.8 of [http://montecarlo.vtt.fi/download/Serpent_manual.pdf Serpent 1 User Manual].

=== set acelib ===

Line 2,149:

Line 3,876:

*If the file path contains special characters it is advised to enclose it within quotes.

−

*A default directory path can be set by defining environment variable SERPENT_DATA. The code looks for cross section directory files in this path if not found at the absolute.

+

*A default directory path can be set by defining environment variable <tt>SERPENT_DATA</tt>. The code looks for cross section directory files in this path if not found at the absolute.

−

*A default cross section directory file can be set by defining environment variable SERPENT_ACELIB. This file will be used if no other path is given with '''set acelib'''.

+

*A default cross section directory file can be set by defining environment variable <tt>SERPENT_ACELIB</tt>.

+

**This file will be used if no other path is given with '''set acelib'''.

=== set adf ===

−

'''set adf''' ''UNI SURF SYM''

+

'''set adf''' ''UNI SURF SYM [ENF]''

−

Sets parameters for the calculation of assembly discontinuity factors. Input values:

+

Sets parameters for the calculation of assembly discontinuity factors (ADFs) and related net and partial currents. Input values:

{|

Line 2,166:

Line 3,894:

| <tt>''SYM''</tt>

| : symmetry option ([[ADF symmetry options|see separate list]])

+

|-

+

| <tt>''ENF''</tt>

+

| : option to switch on (1/yes) or off (0/no) a non-standard calculation approach. The default option is "<tt>off</tt>"

|}

Notes:

+

*ADFs are calculated in the few-group structure for the group constant generation (see [[#set nfg|set nfg]] option).

+

*The calculation of ADFs is currently allowed only for infinite planes and square and hexagonal prisms.

+

**Sign moments of net and partial currents are not scored for [[Surface_types#Regular_prisms|Y-type infinite/truncated hexagonal prisms]].

−

*~~The surface enclosing the universe can be super-imposed (i.e. not part of the geometry definition), but it must enclose the entire universe.~~

+

*Methodology:

−

*~~When~~ the universe is surrounded by zero net-current (reflective) boundary conditions, the ~~ADF's~~ are calculated as the ratios of surface- and volume-averaged heterogeneous flux.

+

**If the universe is surrounded by zero net-current (reflective) boundary conditions, the ADFs are calculated as the ratios of surface- and volume-averaged heterogeneous flux.

−

*~~When~~ the net current is non-zero, the calculation is based on the ratio of surface-averaged homogeneous and heterogeneous flux. The homogeneous flux is obtained from a [[Diffusion flux solver|built-in diffusion flux solver]].

+

**If the net current is non-zero, the calculation is based on the ratio of surface-averaged homogeneous and heterogeneous flux.

−

*~~Calculation parameters for~~ the ~~diffusion~~ flux solver ~~can~~ be ~~set using~~ the [[#~~set dfsol~~|set ~~dfsol~~]] option.

+

***The homogeneous flux is obtained from a [[Diffusion flux solver|built-in diffusion flux solver]].

−

*~~Calculation~~ of ~~ADF's is currently allowed only for planes and infinite square and hexagonal prisms~~.

+

**The default behaviour (standard approach) can be changed via the <tt>''ENF''</tt> parameter:

−

*~~Symmetry~~ options are used to average out the statistical variation in the ~~ADF's~~, which might otherwise lead to systematic errors in core calculations. It is important that the options are used only when the geometry has the corresponding symmetry.

+

***If the flag is "<tt>on</tt>", it enforces a flat homogeneous flux distribution based on mean heterogeneous flux, skipping the diffusion solver, regardless of net-current value.

−

*~~See separate description of~~ [[~~Output parameters~~#~~Assembly discontinuity factors~~|~~output parameters~~]] in ~~the~~ <tt>[input]_res.m</tt>.

+

***The <tt>''ENF''</tt> parameter should be switched on only in rare cases (with understanding of the implications of the calculation setup).

−

*The ADF's can be printed to the [[~~Automated_burnup_sequence#~~Output|group ~~constant output~~]] ~~with~~ [[Input syntax manual#set_coefpara|set coefpara]].

+

*Setup:

+

**The surface is treated as super-imposed on the geometry, i.e. its parameters (coordinates) are relative to the root universe (see [[Input_syntax_manual#set_root|set root]] option).

+

***The surface enclosing the universe can be super-imposed (i.e. not part of the geometry definition), but it must enclose the entire universe.

+

**The symmetry options are used to average out the statistical variation in the ADFs, which might otherwise lead to systematic errors in core calculations.

+

***It is important that the options are used only when the geometry has the corresponding symmetry.

+

**The calculation parameters for the diffusion flux solver can be set using the [[#set dfsol|set dfsol]] option.

+

*The ADFs are written in:

+

** <tt>[input]_res.m</tt> output file: [[Output parameters#Assembly discontinuity factors|homogenized group constants/ADFs]] sub-section

+

** <tt>[input].coe</tt> ouput file, via the [[Input syntax manual#set_coefpara|set coefpara]] option: [[Automated_burnup_sequence#Output|automated burnup sequence/coefficient matrix]] output.

=== set alb ===

Line 2,197:

Line 3,941:

Notes:

−

*~~When this~~ option ~~is set, Serpent calculates~~ both total albedos (ratio of currents) and partial albedos (response matrix).

+

*The option enables the calculation of both total albedos (ratio of currents) and partial albedos (response matrix).

−

*~~The current direction is given relative to~~ the ~~surface normal vectors~~

+

*Albedos are calculated in the few-group structure for the group constant generation (see [[#set nfg|set nfg]] option).

−

*The universe is needed only for labelling the results in the output files.

+

*Setup:

−

*~~See separate description~~ of [[Output parameters#Albedos|~~output parameters~~]].

+

**The universe is needed only for labelling the results in the output files.

+

**The surface is treated as super-imposed on the geometry, i.e. its parameters (coordinates) are relative to the root universe (see [[Input_syntax_manual#set_root|set root]] option).

+

***The surface enclosing the universe can be super-imposed (i.e. not part of the geometry definition), but it must enclose the entire universe.

+

**The current direction is given relative to the surface normal vectors.

+

*The albedo estimates are written in:

+

** <tt>[input]_res.m</tt> output file: [[Output parameters#Albedos|homogenized group constants/albedos]] sub-section

+

** <tt>[input].coe</tt> ouput file, via the [[Input syntax manual#set_coefpara|set coefpara]] option: [[Automated_burnup_sequence#Output|automated burnup sequence/coefficient matrix]] output.

=== set arr ===

Line 2,209:

Line 3,959:

{|

| <tt>''MODEN''</tt>

−

| : mode for neutrons (0 = no reactions included, 1 = include only reactions that affect neutron balance, 2 = include all reactions)

+

| : mode for neutrons (0 = no reactions included, 1 = include only reactions that affect neutron balance, 2 = include all reactions). (default value: 0)

|-

| <tt>''MODEG''</tt>

−

| : mode for photons (0 = no reactions included, 1 = include all reactions)

+

| : mode for photons (0 = no reactions included, 1 = include all reactions). (default value: 0)

|}

Notes:

−

*Analog reaction rates are calculated by counting sampled events and printed in a separate output file.

+

*Analog reaction rates are calculated by counting sampled events and printed in a separate output file <tt>[input]_arr[bu].m</tt>, where "<tt>bu</tt>" is the burnup step.

−

*~~See~~ detailed description on the [[Description of output files#Reaction rate output|reaction rate output file]].

+

*For more information, see the detailed description on the [[Description of output files#Reaction rate output|reaction rate output file]].

−

=== set bc ===

+

=== set ba ===

−

'''set bc''' ''~~MODE~~''

+

'''set ba''' ''ZAI1 ZAI2 ...''

−

~~Sets the boundary conditions for all outer boundaries of the geometry~~. Input values:

+

Defines isotopes handled separately as burnable absorbers. Input values:

{|

−

| <tt>''~~MODE~~''</tt>

+

| <tt>''ZAIn''</tt>

−

| : ~~boundary type~~ (~~1 = vacuum~~, ~~2 = reflective, 3 = periodic~~)

+

| : nuclide identifiers ([[Definitions, units and constants#definitions|ZAI]])

|}

+

Notes:

−

'''set bc''' ''~~MODE ALB~~''

+

*This input parameter can be used to separate the transmutation chains.

−

Sets ~~the boundary conditions with albedo for all outer boundaries of the geometry~~. Input values:

+

**Some burnup applications require separate treatment for isotopes that are used as burnable absorbers but also produced in fission.

+

*Isotope handled as the burnable absorber is created by duplicating the original and renaming it as ''ZAIn + 1000''.

+

**For Gd-155, for example, the fission product isotope would be assigned ZAI 641550 and the burnable absorber ZAI 642550.

+

*The input parameter defines the entire transmutation chain.

+

**Listing Gd-isotopes 641540 641550 641560 641570 641580 creates a transmutation path from Gd-154 to Gd-158.

+

**Listing only the main absorbers (641550 641570) produces a different result, since the capture products of Gd-155 and Gd-157 are lost.

+

=== set bala ===

+

'''set bala''' ''OPT''

+

Sets OpenMP load balancing on or off. Input values:

{|

−

| <tt>''~~MODE~~''</tt>

+

| <tt>''OPT''</tt>

−

| : ~~boundary type~~ (1 = ~~vacuum~~, 2 = ~~reflective, 3 = periodic~~)

+

| : probability to store particles in common queue (0 = off, non-zero = on)

−

|-

+

−

~~| <tt>''ALB''</tt>~~

+

−

~~| : albedo~~

+

|}

+

Notes:

+

*Load balancing may improve OpenMP parallel scalability in calculations with significant branching.

+

**Most typically related to coupled neutron/photon calculations or variance reduction.

+

*Default value:

+

**It is "<tt>on</tt>" with <tt>''OPT''</tt>= 1 with weight-window/variance reduction calculations and dynamic/time-dependent calculation modes.

+

**Otherwise, it is set "<tt>off</tt>".

+

**Before version 2.2.0, the default behaviour was always "<tt>off</tt>".

+

*When this option is set, the random number sequence is no longer preserved.

+

=== set bc ===

+

'''set bc''' ''MODE''

+

'''set bc''' ''MODE ALB''

'''set bc''' ''MODEX MODEY MODEZ''

−

Sets the boundary conditions ~~separately for x-, y- and z-directions~~. Input values:

+

'''set bc''' ''MODEX MODEY MODEZ ALB''

+

Sets the boundary conditions (BCs). Input values:

{|

+

| <tt>''MODE''</tt>

+

| : boundary condition type in all directions

+

|-

| <tt>''MODEX''</tt>

−

| : boundary type in x-direction ~~(1 = vacuum, 2 = reflective, 3 = periodic)~~

+

| : boundary condition type in x-direction

|-

| <tt>''MODEY''</tt>

−

| : boundary type in y-direction ~~(1 = vacuum, 2 = reflective, 3 = periodic)~~

+

| : boundary condition type in y-direction

|-

| <tt>''MODEZ''</tt>

−

| : boundary type in z-direction ~~(1 = vacuum, 2 = reflective, 3 = periodic)~~

+

| : boundary condition type in z-direction

|-

+

| <tt>''ALB''</tt>

+

| : albedo

|}

−

~~'''set bc''' ''MODEX MODEY MODEZ ALB''~~

+

The possible boundary condition types are:

−

~~Sets the~~ boundary ~~conditions with albedo separately for x-, y- and z-directions. Input values~~:

+

::{| class="wikitable" style="text-align: left;"

−

+

! Type

−

{|

+

! Description

−

~~| <tt>''MODEX''</tt>~~

+

! Notes

−

~~| : boundary type in x-direction (1 = vacuum, 2 = reflective, 3 = periodic)~~

+

|-

−

| <tt>~~''MODEY''~~</tt>

+

| <tt>1, black</tt>

−

| : boundary ~~type in y-direction~~ (~~1 = vacuum, 2 = reflective, 3 = periodic~~)

+

| vacuum boundary condition(s)

+

| the particle is killed

|-

−

| <tt>~~''MODEZ''~~</tt>

+

| <tt>2, reflective</tt>

−

| ~~: boundary type in z-direction~~ (~~1 = vacuum, 2 =~~ reflective, 3 = periodic)

+

| repeated (reflective) boundary condition(s)

+

| the particle is reflected back into the geometry

+

|-

+

| <tt>3, periodic</tt>

+

| repeated (periodic) boundary condition(s)

+

| the particle is moved to the opposite side of the geometry

|-

−

~~| <tt>''ALB''</tt>~~

−

~~| : albedo~~

|}

Notes:

−

+

*The default boundary condition is vacuum in all directions.

−

*The boundary conditions can be set ~~either~~ for all directions at once ~~(single parameter) or~~ x-, y- ~~and~~ z-~~directions~~ separately ~~(three parameters). Albedos are provided~~ by adding one ~~more~~ parameter in the list.

+

*Direction-wise boundary conditions:

−

*~~The default boundary condition is vacuum (= 1) in all directions.~~

+

**Boundary conditions can be set for all directions at once: <tt>''MODE''</tt>.

−

*Albedo boundary conditions are invoked by multiplying the particle weight with factor ''ALB'' each time a reflective or periodic boundary is hit.

+

**Boundary conditions can be set for x-/y-/z- direction separately: <tt>''MODEX''</tt>, <tt>''MODEY''</tt>, and <tt>''MODEZ''</tt>

−

*Repeated boundary conditions (reflective or periodic) are based on universe transformations, which limits outer boundary to surfaces that form regular lattices (square and hexagonal prisms, rectangles, cubes and cuboids).

+

*Boundary conditions can be defined with albedos by adding one additional parameter in the list, <tt>''ALB''</tt>.

−

*~~Repeated boundary conditions~~ are applied on the first surface of outside cells (see definition of outside cells in the [[#cell (cell definition)|cell card]])

+

**Albedo boundary conditions are invoked by multiplying the particle weight with factor <tt>''ALB''</tt> each time a reflective or periodic boundary is hit.

−

*For symmetry ~~purposes Serpent provides~~ the [[#set usym|~~universe symmetry option~~]].

+

*Repeated boundary conditions (reflective or periodic):

−

*For more information, see [[Boundary conditions|~~detailed description on boundary~~ conditions]].

+

**They are based on universe transformations, which limits outer boundary to surfaces that form regular lattices (square and hexagonal prisms, rectangles, cubes and cuboids).

+

**They are applied on the first surface of outside cells (see definition of outside cells in the [[#cell (cell definition)|cell card]])

+

*For universe symmetry options, see the [[#set usym|set usym]] option.

+

*For more information, see the detailed description on the [[Boundary conditions|Boundary conditions]].

=== set blockdt ===

Line 2,295:

Line 4,081:

Notes:

−

*This option is used to override selection of tracking mode based on the probability threshold (see [[#set dt|set dt]]) in individual materials.

+

*This option is used to override selection of tracking mode based on the probability threshold (see [[#set dt|set dt]] option) in individual materials.

−

*~~Use~~ of delta-tracking can be forced in individual materials using [[#set forcedt|set forcedt]].

+

*The use of delta-tracking can be forced in individual materials using [[#set forcedt|set forcedt]] option.

*For more information on tracking modes, see the detailed description on [[delta- and surface-tracking]].

*''Note to developers: should have different lists for neutrons and photons?''

Line 2,311:

Line 4,097:

Notes:

−

*Isomeric branching data libraries are standard ENDF format files containing energy-dependent branching ratios. The data is read from ENDF files 9 and 10.

−

*Serpent uses [[Default isomeric branching ratios|constant branching ratios]] by default. The default values can be overridden using the [[#set isobra|set isobra]] option. Energy-dependent data read read from ENDF format files overrides the constant ratios.

*If the file path contains special characters it is advised to enclose it within quotes.

*A default directory path can be set by defining environment variable SERPENT_DATA. The code looks for decay data files in this path if not found at the absolute.

−

*See ~~also~~: [[Branching ratio example|example input]]

+

*Isomeric branching data libraries are standard ENDF format<ref name="endf">Trkov, A., Herman, M. and Brown, D. A. ''"ENDF-6 Formats Manual."'' CSEWG Document ENDF-102 / BNL-90365-2009 Rev. 2 [https://www.nndc.bnl.gov/endf-b8.0/endf-manual-viii.0.pdf (2018)]</ref> files containing energy-dependent branching ratios. The data is read from ENDF files 9 and 10.

−

*~~Example~~ data ~~from~~ the [~~http~~://~~virtual~~.~~vtt~~.fi/~~virtual~~/~~montecarlo/misc~~/~~sss_jeff31a~~.~~bra JEFF~~-3.1 ~~activation file~~]

+

*Serpent uses [[Default isomeric branching ratios|constant branching ratios]] by default.

+

**The default values can be overridden using the [[#set isobra|set isobra]] option. In which case, the energy-dependent data read from ENDF format files override the constant ratios.

+

*See a practical example on how to evaluate branching ratios: [[Branching ratio example|example input]].

+

**The isomeric branching data library corresponds to the JEFF-3.1 activation file [[File:JEFF-3.1_activation_file.tgz]].

+

=== set branchless ===

+

'''set branchless''' ''OPT'' [ ''WGT_LOW'' ''WGT_HIGH'' ]

+

Option that enables the branchless collision method for variance reduction. Input values:

+

{|

+

| <tt>''OPT''</tt>

+

| : option to switch calculation on (1/yes) or off (0/no). The default option is "<tt>off</tt>".

+

|-

+

| <tt>''WGT_LOW''</tt>

+

| : weight lower-boundary (default value: 0.2)

+

|-

+

| <tt>''WGT_HIGH''</tt>

+

| : weight upper-boundary (default value: 10.0)

+

|}

+

Notes:

+

*The branchless algorithm suppresses the variability due to the simultaneous propagation of the several branches associated to a fission event

+

*The branchless method uses analog scattering combined with forced fission so that after each collision, the neutron is either a scattering neutron or a fission neutron.

+

**In a non-multiplying method, the branchless method behaves as implicit capture.

+

*The branchless method sets the following simulation configuration: reaction sampling ([[#set nphys|set nphys 1 1 1]]), reaction modes ([[#set impl|set impl 0 1 1]]), and population control ([[#set combing|set combing 1]]), overriding any user-defined option.

+

*The current implementation does not support the use of the branchless collision method combined with the unresolved resonance probability table sampling (see [[#set ures|set ures]] option).

=== set bumode ===

−

'''set bumode''' ''MODE'' [ ''ORDER'' ]

+

'''set bumode''' ''MODE'' [ ''ORDER'' ''SSD'' ]

Sets the burnup calculation mode. Input values:

Line 2,327:

Line 4,136:

{|

| <tt>''MODE''</tt>

−

| : burnup calculation mode

+

| : burnup calculation mode (default value: 2 = CRAM)

|-

| <tt>''ORDER''</tt>

−

| : CRAM order

+

| : CRAM order (default value: 14 - 14 PFD CRAM)

+

|-

+

| <tt>''SSD''</tt>

+

| : number of substeps for CRAM decay steps (default value: 0 = use TTA)

|}

The possible settings for mode are:

−

{| class="wikitable" style="text-align: left;"

+

::{| class="wikitable" style="text-align: left;"

! Mode

! Description

Line 2,346:

Line 4,158:

|}

−

The CRAM order parameter can only be given when choosing the ~~cram~~ mode. The possible settings for CRAM order are:

+

The CRAM order parameter can only be given when choosing the CRAM mode. The possible settings for CRAM order are:

−

{| class="wikitable" style="text-align: left;"

+

::{| class="wikitable" style="text-align: left;"

! CRAM order

−

|-

| <tt>2</tt>

−

|-

| <tt>4</tt>

−

|-

| <tt>6</tt>

−

|-

| <tt>8</tt>

−

|-

| <tt>10</tt>

−

|-

| <tt>12</tt>

−

|-

| <tt>14</tt>

−

|-

| <tt>16</tt>

+

| <tt>-16</tt>

+

| <tt>-48</tt>

|}

Notes:

−

*~~The default setting for~~ the burnup ~~calculation mode is CRAM~~.

+

*Positive values refer to PFD form of CRAM. Negative values of CRAM order mean using IPF form of CRAM with order of the absolute value of the parameter.

−

*~~Default value for the~~ CRAM ~~order is 14~~.

+

*Decay calculations (see [[#dep (depletion history)|dep (depletion history)]]) and burnup calculations with very low flux are always calculated with TTA disregarding this input before version 2.1.32.

−

*The ~~CRAM order must be divisible by 2 and any values greater than 16~~ are ~~considered~~ to ~~be 16~~.

+

**The latter, very low flux condition, only applies to calculations not involving continuous reprocessing.

+

*Positive values of <tt>''SSD''</tt> enforce usage of CRAM with given number of substeps. A zero value of <tt>''SSD''</tt> enforces usage of TTA.

+

*The Serpent 1 <tt>''MODE''</tt> 3, a variation TTA method, in which cyclic transmutation chains are handled by inducing small variations in the coefficients instead of solving the extended TTA equations, is overwritten by the standard TTA method <tt>''MODE''</tt> 1.

+

=== set bunorm ===

+

'''set bunorm''' ''NORM''

+

Sets the burnup calculation normalization mode if it is not bound to a single material. Input values:

+

{|

+

| <tt>''NORM''</tt>

+

| : burnup calculation normalization mode (1 = all materials, 2 = burnable materials, 3 = non-burnable materials). (default value: 1)

+

|}

=== set ccmaxiter ===

Line 2,380:

Line 4,199:

{|

| <tt>''NITER''</tt>

−

| : number of iterations.

+

| : number of iterations (default value: 1 = no iteration)

|}

Notes:

−

*Default maximum number of iterations is 1 (no iteration).

*The iteration is stopped when either the maximum number of iterations or the maximum active neutron population (set with [[#set ccmaxpop|set ccmaxpop]]) has been simulated.

−

*~~See~~ [[Coupled multi-physics calculations]] ~~for further information~~.

+

*For more information, see the detailed description on [[Coupled multi-physics calculations|Couple multi-physics calculations]].

=== set ccmaxpop ===

Line 2,396:

Line 4,214:

{|

| <tt>''CPOP''</tt>

−

| : total active population to simulate.

+

| : total active population to simulate (default value: [[Definitions, units and constants#Constants|INFTY]]/1E6)

|}

Notes:

−

*Default maximum population is [[Definitions, units and constants#Constants|INFTY]]/1e6.

*The iteration is stopped when either the maximum number of iterations (set with [[#set ccmaxiter|set ccmaxiter]]) or the maximum active neutron population has been simulated.

*Only the population simulated during active cycles is included in this amount.

*This is mostly useful if the neutron population per iteration is not constant.

−

*~~See~~ [[Coupled multi-physics calculations]] for ~~further information~~.

+

*For more information, see the detailed description on [[Coupled multi-physics calculations|Couple multi-physics calculations]].

+

=== set cdop ===

+

'''set cdop''' ''OPT''

+

Sets the Doppler broadening method for the energy spectrum of the scattered photons. Input values:

+

{|

+

| <tt>''OPT''</tt>

+

| : option to set Doppler broadening method off (0/no) or on (1/yes). The default option is "<tt>on</tt>".

+

|}

+

Notes:

+

*If the Doppler broadening method is switched "<tt>off</tt>", the incoherent scattering function approximation is used for calculating the energy.

+

*In both cases, the direction of the photon is calculated using the incoherent scattering function.

+

*The photon transport physics model is described in a related paper<ref name="photon">Kaltiaisenaho, T. ''"Photon transport physics in Serpent 2 Monte Carlo code."'' Comp. Phys. Comm., [https://doi.org/10.1016/j.cpc.2020.107143 ''252'' (2020) 107143.]</ref>

+

=== set cea ===

+

'''set cea''' ''OPT''

+

Sets the Compton electron angular distribution model on and off. Input values:

+

{|

+

| <tt>''OPT''</tt>

+

| : option to set the Compton electron angular distribution model off (0/no) or on (1/yes). The default option is "<tt>on</tt>".

+

|}

+

Notes:

+

*Electron travels in the direction of the momentum transfer vector. This is equal to the free-electron scattering angle when Doppler broadening is not used.

+

*The photon transport physics model is described in a related paper<ref name="photon" />

=== set cfe ===

Line 2,414:

Line 4,260:

{|

| <tt>''LN''</tt>

−

| : minimum mean distance for scoring the CFE for neutrons

+

| : minimum mean distance for scoring the CFE for neutrons [in cm] (default value: 20.0)

|-

| <tt>''TN''</tt>

−

| : minimum mean time interval for scoring the CFE for neutrons

+

| : minimum mean time interval for scoring the CFE for neutrons [in s]

|-

| <tt>''LG''</tt>

−

| : minimum mean distance for scoring the CFE for photons

+

| : minimum mean distance for scoring the CFE for photons [in cm] (default value: 20.0)

|-

| <tt>''TG''</tt>

−

| : minimum mean time interval for scoring the CFE for photons

+

| : minimum mean time interval for scoring the CFE for photons [in s]

|}

Notes:

−

*The use of delta-tracking necessitates the use of CFE for scoring the integral reaction rates. The scoring is based on both real and virtual collision to improve the statistics in low density regions (and short time intervals).

+

*The use of delta-tracking necessitates the use of CFE for scoring the integral reaction rates.

−

*The minimum mean distance is the statistical mean-free-path (mfp) of collisions that contribute to the CFE. Collisions are more frequent if the physical mfp is shorter.

+

**The scoring is based on both real and virtual collision to improve the statistics in low density regions (and short time intervals).

+

*The minimum mean distance is the statistical mean-free-path (mfp) of collisions that contribute to the CFE.

+

**Collisions are more frequent if the physical mfp is shorter.

*In time-dependent simulations it may be more convenient to define the minimum mean time between two collisions, to get sufficient statistics for short time bins.

−

*~~The default minimum mean scoring distance is 20 cm for both neutrons and photons.~~ Adjusting the distance affects both statistics and running time, but it should be noted that no studies have been performed on what the optimal value should be.

+

*Adjusting the distance affects both statistics and running time, but it should be noted that no studies have been performed on what the optimal value should be.

−

*Only one criterion can be provided for each particle type. If distance is given, time must be set to -1 and vice versa.

+

*Only one criterion can be provided for each particle type.

+

**If distance is given, time must be set to "<tt>-1</tt>" and vice versa.

*For more information on tracking modes and CFE, see the detailed descriptions on [[delta- and surface-tracking]] and [[Result estimators#Implicit estimators|result estimators]].

−

*The collision flux estimator ~~in Serpent~~ is described in ~~an article in Annals of Nuclear energy from 2017~~.<ref name="cfe">Leppänen, J.

+

*The collision flux estimator methodology is described in a related paper.<ref name="cfe">Leppänen, J.

''"On the use of delta-tracking and the collision flux estimator in the Serpent 2 Monte Carlo particle transport code."'' Ann. Nucl. Energy [http://www.sciencedirect.com/science/article/pii/S0306454916311367 '''105''' (2017) 161-167].</ref>

*In version 2.1.27 and earlier the name of this input option was "set minxs".

+

=== set cmm ===

+

'''set cmm''' ''OPT''

+

Sets calculation of diffusion coefficients using the cumulative migration method (CMM) on or off. Input values:

+

{|

+

| <tt>''OPT''</tt>

+

| : option to switch CMM calculation on (1/yes) or off (0/no)

+

|}

+

Notes:

+

*Methodology:

+

**The CMM diffusion coefficients and transport cross sections are reasonable only when they are calculated over entire geometry:

+

***The homogenized region covers the entire geometry and is surrounded by periodic or reflective boundary conditions.

+

***This means that e.g. pin cell diffusion coefficients can not be calculated from a 2D fuel assembly calculation.

+

**The CMM methodology was revised in version 2.1.31 so that the calculated values may be different than with previous versions.

+

**One may try to approximate the CMM estimates with the transport correction for hydrogen for light water reactor applications (see [[#set trc|set trc]] option).

+

*Setup:

+

**CMM diffusion coefficients and transport cross sections can be calculated also when using implicit capture reactions (see [[#set_impl|set impl]] option), from version 2.1.31 and on.

+

**The calculation of CMM estimates (diffusion coefficients and transport cross sections) might take considerable time. Switch "<tt>off</tt>" the evaluation if the data is not needed.

+

**The use of private results array may be recommended when calculating CMM estimates (see [[#set_shbuf|set shbuf]] option).

+

*The CMM diffusion coefficients <tt>CMM_DIFFCOEF</tt> and transport cross sections <tt>CMM_TRANSPXS</tt> estimates are written in:

+

** <tt>[input]_res.m</tt> output file: [[Output parameters#Homogenized group constants|homogenized group constants]] section - diffusion parameters: for infinite spectrum and critical spectrum.

+

** <tt>[input].coe</tt> ouput file, via the [[Input syntax manual#set_coefpara|set coefpara]] option: [[Automated_burnup_sequence#Output|automated burnup sequence/coefficient matrix]] output.

+

*The cumulative migration method (CMM) is described in related papers<ref>Liu, Z., Smith, K., Forget, B. and Ortensi, J. ''"Cumulative migration method for computing rigorous diffusion coefficients and transport cross sections from Monte Carlo."'' Ann. Nuc. Energy, [https://doi.org/10.1016/j.anucene.2017.10.039 '''112''' (2016) 126-136]</ref><ref>Liu, Z., Smith, K. and Forget, B. ''"Group-wise Tally Scheme of Incremental Migration Area for Cumulative Migration Method."'' In Proceedings of the PHYSOR 2018 (2018) 2512-2523</ref>.

=== set coefpara ===

Line 2,444:

Line 4,320:

{|

| <tt>''FMT''</tt>

−

| : output format, currently used for including or excluding statistical errors (0 = not included, 1 = included)

+

| : output format, currently used for including or excluding statistical errors (0 = not included, 1 = included). (default value: 0)

|-

| <tt>''PARAMn''</tt>

Line 2,451:

Line 4,327:

Notes:

+

*List of parameters or detectors to include:

+

**The available parameters are listed under [[Output parameters#Homogenized group constants|homogenized group constants]] in the description of the <tt>[input]_res.m</tt> output file.

+

**Detectors are identified by the name assigned to them in the [[#det (detector definition)|det card]].

+

*The group constant output file <tt>[input].coe</tt> is produced when the [[automated burnup sequence]] is invoked.

−

*The group constant output file [input].coe is produced when the [[automated burnup sequence]] is invoked.

+

=== set combing ===

−

*The available parameters are listed under [[Output parameters#Homogenized group constants|homogenized group constants]] in the description of the [input]_res.m output file.

+

−

*Detectors are identified by the name assigned to them in the [[#det (detector definition)|detector card]].

+

−

~~=== set cmm ===~~

+

'''set combing''' ''MODE''

−

+

Option that enables the combing approach for precursors population control as an alternative to Russian roulette and splitting in dynamic source simulations. Input values:

−

'''set ~~cmm~~''' ''~~OPT~~''

+

−

~~Sets calculation of diffusion coefficients using~~ the ~~cumulative migration method (CMM) on or off~~. Input values:

+

{|

−

| <tt>''~~OPT~~''</tt>

+

| <tt>''MODE''</tt>

−

| : ~~option to switch CMM calculation on~~ (1~~/yes~~) ~~or off~~ (0~~/no~~)

+

| : combing population-control mode (0 = none, 1 = weight-based, 2 = emission-based). (default value: 0)

|}

Notes:

−

*~~Calculation of [[Output_parameters#Diffusion_parameters|diffusion coefficients using CMM]] takes considerable~~ time ~~when~~ the ~~number of energy groups is large~~. ~~This option allows switching~~ the ~~calculation off if~~ the ~~data is not needed~~.

+

*The combing method can achieve variance reduction and save computer time by keeping the population size approximately constant over time steps.

+

**In super-critical systems, it prevents the population from growing without bound.

+

**In sub-critical systems, it prevents the population from dying.

+

**In critical systems, it avoids the divergence of the variance of the population due to fluctuations of fission chains.

=== set comfile ===

Line 2,485:

Line 4,364:

*Setting up a communication mode will enable the coupled calculation mode.

−

*For more information see: [[Coupled_multi-physics_calculations#External_coupling|External coupling]]

+

*The communication options [[#set comfile|set comfile]], [[#set ppid|set ppid]] and [[#set pport|set pport]] are mutually exclusive, aka, multiple signalling modes are not allowed.

+

*For more information, see the detailed description on [[Coupled_multi-physics_calculations#External_coupling|External coupling]]

=== set confi ===

Line 2,494:

Line 4,374:

{|

| <tt>''OPT''</tt>

−

| : option to set confidentiality flag on (1/yes) or off (0/no)

+

| : option to set confidentiality flag on (1/yes) or off (0/no). The default option is "<tt>off</tt>"

|}

Notes:

−

*This option can be used to label calculations as confidential. If the option is set, text "(CONFIDENTIAL)" is printed in the run-time output next to the [[#set title|calculation title]] and the value of variable CONFIDENTIAL_DATA in the [input]_res.m output file is set to 1.

+

*This option can be used to label calculations as confidential. If the option is set, text "(CONFIDENTIAL)" is printed in the run-time output next to the [[#set title|calculation title]] and the value of variable CONFIDENTIAL_DATA in the <tt>[input]_res.m</tt> output file is set to "1".

+

=== set coverxlib ===

+

'''set coverxlib''' ''LIB1'' [ ''LIB2'' ''LIB3'' ... ]

+

Sets COVERX-format multi-group covariance data file paths. Input values:

+

{|

+

| <tt>''LIBn''</tt>

+

| : file paths to multi-group covariance data files in the COVERX format<ref name="coverx">Wieselquist, W. A. and Lefebvre, R. A (ed.), ''"SCALE 6.3.1 User Manual: Sensitivity and Uncertainty Analysis - Appendix 6.3.4.1.6. COVERX format"'', ORNL/TM-SCALE-6.3.1, UT-Battelle, LLC, Oak Ridge National Laboratory, Oak Ridge, TN [https://scale-manual.ornl.gov/tsunami-ip-appAB.html#coverx-format (2023)]</ref> (ASCII or binary)

+

|}

+

Notes:

+

*It enables first-order uncertainty propagation by collapsing the covariance data with the evaluated sensitivities.

+

**It applies the Sandwich rule: <math>\mathbf{Cov}^R_X \approx ({\overline{\mathbf{S}}}^R_X)^T {\overline{\overline{\mathbf{Cov}}}}^R_{X,X} \overline{\mathbf{S}}^R_X</math>

+

:: where: <math>{\overline{\mathbf{S}}}^R_X \in \R^{N_g \times 1} </math> is the sensitivity vector containing the group sensitivities

+

::::<math>{\overline{\overline{\mathbf{Cov}}}}^R_{X,X} \in \R^{N_g \times N_g}</math> is the covariance matrix containing the group covariances

+

*The methodology is described in a related report<ref name="UncReport18">Valtavirta, V. ''"Nuclear data uncertainty propagation to Serpent generated group and time constants"'', Research report VTT-R-04681-18 [http://montecarlo.vtt.fi/download/VTT-R-04681-18_web.pdf (2018)].</ref>.

+

*It requires setting the sensitivity calculation parameters. For more information, see the detailed description on [[Sensitivity calculations|sensitivity calculations]].

+

=== set covlib ===

+

'''set covlib''' ''LIB1'' [ ''LIB2'' ''LIB3'' ... ]

+

Sets plain ASCII multi-group covariance data file paths. Input values:

+

{|

+

| <tt>''LIBn''</tt>

+

| : file paths to multi-group covariance data files in the plain ASCII format (ASCII or binary)

+

|}

+

The syntax of the file containing the covariance data is:

+

::{| class="toccolours" style="text-align: left;"

+

|-

+

| ''NG'' ''E1'' ... ''ENG+1'' ''NM''

+

|-

+

| ''ZAI1,1'' ''MT1,1'' ''ZAI1,2'' ''MT1,2''

+

|-

+

| ''COV1,1,1'' ... ''COV1,NG,NG''

+

|-

+

|...

+

|-

+

| ''ZAINM,1'' ''MTNM,1'' ''ZAINM,2'' ''MTNM,2''

+

|-

+

| ''COVNM,1,1'' ... ''COVNM,NG,NG''

+

|-

+

|}

+

where:

+

{|

+

| <tt>''NG''</tt>

+

|: number of neutron energy groups

+

|-

+

| <tt>''Eg''</tt>

+

|: energy grid boundaries [in MeV]

+

|-

+

| <tt>''NM''</tt>

+

|: number of covariance matrixes

+

|-

+

| <tt>''ZAIm,n'', ''MTm,n''</tt>

+

|: 2 × nuclide ([[Definitions, units and constants#definitions|ZAI]])-reaction ([[ENDF reaction MT's and macroscopic reaction numbers#ENDF Reaction MT's|ENDF reaction MT]]) pairs defining the ''m''-th covariance matrix

+

|-

+

| <tt>''COV''m,g,g''</tt>

+

|: ''NG'' × ''NG'' covariance data corresponding to the ''m''-th matrix

+

|}

+

Notes:

+

*It enables first-order uncertainty propagation by collapsing the covariance data with the evaluated sensitivities.

+

**It applies the Sandwich rule: <math>\mathbf{Cov}^R_X \approx ({\overline{\mathbf{S}}}^R_X)^T {\overline{\overline{\mathbf{Cov}}}}^R_{X,X} \overline{\mathbf{S}}^R_X</math>

+

:: where: <math>{\overline{\mathbf{S}}}^R_X \in \R^{N_g \times 1} </math> is the sensitivity vector containing the group sensitivities

+

::::<math>{\overline{\overline{\mathbf{Cov}}}}^R_{X,X} \in \R^{N_g \times N_g}</math> is the covariance matrix containing the group covariances

+

*The methodology is described in a related report<ref name="UncReport18">Valtavirta, V. ''"Nuclear data uncertainty propagation to Serpent generated group and time constants"'', Research report VTT-R-04681-18 [http://montecarlo.vtt.fi/download/VTT-R-04681-18_web.pdf (2018)].</ref>.

+

*It requires setting the sensitivity calculation parameters. For more information, see the detailed description on [[Sensitivity calculations|sensitivity calculations]].

=== set cpd ===

−

'''set cpd''' ''DEPTH'' [ ''NZ ZMIN ZMAX'' ]

+

'''set cpd''' ''DEPTH'' [ ''NZ ZMIN ZMAX'' ] [ ''LVL1'' ''LVL2'' ]

−

Sets on the calculation of lattice-wise power distributions to output file [input]_core0.m on. Input values:

+

Sets on the calculation of lattice-wise power distributions to output file <tt>[input]_core0.m</tt> on. Input values:

{|

| <tt>''DEPTH''</tt>

−

| : The number of ~~levels included. 1 is the first~~ lattice ~~calculated from universe 0 usually corresponding to assembly~~-~~wise distribution. 2 includes the first two~~ levels ~~usually corresponding to the assembly- and pin-wise distributions~~.

+

| : The number of lattice-levels included.

|-

| <tt>''NZ''</tt>

−

| : Number of equal sized axial bins into which the lattices are divided.

+

| : Number of equal sized axial bins into which the lattices are divided (default value: 1)

|-

| <tt>''ZMIN''</tt>

−

| : Minimum z-coordinate for the axial division.

+

| : Minimum z-coordinate for the axial division [in cm] (default value: [[Definitions, units and constants#Constants|-INFTY]])

|-

| <tt>''ZMAX''</tt>

−

| : Maximum z-coordinate for the axial division.

+

| : Maximum z-coordinate for the axial division [in cm] (default value: [[Definitions, units and constants#Constants|INFTY]])

+

|-

+

| <tt>''LVL1''</tt>

+

|: User-defined first level where to define the lattice-wise power distribution

|-

+

| <tt>''LVL2''</tt>

+

|: User-defined second level where to define the lattice-wise power distribution

|}

Notes:

−

* The ~~default values for~~ <tt>''~~NZ~~''</tt>, <tt>''~~ZMIN~~''</tt> ~~and <tt>''ZMAX''</tt> are 1~~, -~~INFTY~~ and ~~INFTY, respectively~~.

+

*The interpretation of the number of levels included is as follows:

+

** <tt>''DEPTH''</tt> 1: includes the first level from the root universe, which "usually" corresponds to the assembly-wise distribution.

+

** <tt>''DEPTH''</tt> 2: includes the first two levels from the root universe, which "usually" corresponds to the assembly- and pin-wise distributions.

=== set cpop ===

'''set cpop''' ''NPG'' ''NGEN'' ''NSKIP'' [ ''NSKIP2'' ]

−

Sets parameters for simulated neutron population for corrector neutron transport solutions in burnup calculation. Typically used with the [[Stochastic Implicit Euler burnup scheme|SIE burnup scheme]]. Input values

+

Sets parameters for simulated neutron population for corrector neutron transport solutions in burnup calculation. Typically used with the [[Stochastic Implicit Euler burnup scheme|SIE burnup scheme]]. Input values:

{|

Line 2,560:

Line 4,522:

*Only source points from active cycles are included.

+

*From version 2.2.1 and on, multi-step depletion source files can be generated <tt>[''FILE'']_[bu]</tt>, where "<tt>bu</tt>" is the burnup step. Otherwise, simply, <tt>[''FILE'']</tt>.

+

=== set dataout ===

+

'''set dataout''' ''TABLE_LIST''

+

Defines the tables included in the nuclear and material data file <tt>[input].out</tt>. Input values:

+

{|

+

| <tt>''TABLE_LIST''</tt>

+

| : list of tables (default value: <tt>all/0</tt>)

+

|}

+

Possible list of tables:

+

Possible key-words/variables are:

+

::{| class="wikitable" style="text-align: left;"

+

! Key-word

+

! Table ID

+

! Description

+

|-

+

| <tt>0, all</tt>

+

|

+

| include all available tables

+

|-

+

| <tt>1, nuc_summary</tt>

+

| Table 1: Summary of nuclide data

+

|

+

|-

+

| <tt>2, nuc_readec</tt>

+

| Table 2: Reaction and decay data

+

|

+

|-

+

| <tt>3, nuc_nfy</tt>

+

| Table 3: Fission yield data

+

| only in burnp mode

+

|-

+

| <tt>4, nuc_lostpath</tt>

+

| Table 4: Lost transmutation paths

+

| only in burnup mode

+

|-

+

| <tt>5, mat_summary</tt>

+

| Table 1: Summary of material compositions

+

|

+

|-

+

| <tt>8, allnuc</tt>

+

|

+

| (nuclide) Tables 1-4

+

|-

+

| <tt>9, allmat</tt>

+

|

+

| (material) Tables 1

+

|-

+

| <tt>-1</tt>

+

|

+

| omit the <tt>[input].out</tt> file

+

|}

+

Notes:

+

*The output file data is divided into two sections: nuclear data (Tables 1-4) and material data (Table 1). Respectively, they include all the nuclides and their reactions as they are read from the nuclear data libraries, and the material data includes isotopic compositions and densities, as well as volumes and masses if available.

+

*For more information, see detailed description of the [[Description of output files#Nuclide and material data output|nuclear and material data output]].

=== set dbrc ===

−

'''set dbrc''' ''Emin Emax~~'' [ ''~~NUC1 NUC2 '' ... ]

+

'''set dbrc''' ''Emin Emax NUC1'' [ ''NUC2'' ... ]

−

Enables the use of doppler-broadening rejection correction (DBRC).

+

Enables the use of doppler-broadening rejection correction (DBRC). Input values:

{|

| <tt>''Emin''</tt>

−

| : Minimum energy for DBRC

+

| : Minimum energy for DBRC [in MeV]

|-

| <tt>''Emax''</tt>

−

| : Maximum energy for DBRC

+

| : Maximum energy for DBRC [in MeV]

|-

| <tt>''NUCn''</tt>

−

| : ~~Nuclide~~ identifiers for which to apply DBRC ~~to, with 0 K cross section data,~~ e.g. "92238.00c"

+

| : zero-kelvin nuclide identifiers for which to apply DBRC (e.g. "92238.00c")

|}

Notes:

−

*This description is not complete.

*Use of DBRC requires 0 K cross section data.

*See also Section 5.6 of [http://montecarlo.vtt.fi/download/Serpent_manual.pdf Serpent 1 User Manual].

+

*This input could be given without any nuclides before version 2.1.32. Then DBRC was not used at all.

+

=== set dd ===

+

'''set dd''' ''MODE'' [ ''X0'' ''Y0'' ''α0'' ]

+

Invokes domain decomposition. Input values:

+

{|

+

| <tt>''MODE''</tt>

+

| : decomposition mode (default value: 0)

+

|-

+

| <tt>''X0''</tt>

+

| : x-coordinate of the domain decomposition origin (centre of the radial division, initial position of the angular division) [in cm] (default value: 0.0)

+

|-

+

| <tt>''Y0''</tt>

+

| : y-coordinate of the domain decomposition origin (centre of the radial division, initial position of the angular division) [in cm] (default value: 0.0)

+

|-

+

| <tt>''α0''</tt>

+

| : angular position of the domain decomposition origin [in degrees] (default value: 0.0)

+

|}

+

The possible modes are:

+

::{| class="wikitable" style="text-align: left;"

+

! Mode

+

! Description

+

! Notes

+

|-

+

| <tt>0</tt>

+

| none

+

|

+

|-

+

| <tt>1</tt>

+

| depletion zone indexing-based decomposition

+

| not recommended

+

|-

+

| <tt>2</tt>

+

| sector-based decomposition

+

| <tt>''X0''</tt>, <tt>''Y0''</tt> and <tt>''α0''</tt> are available

+

|-

+

| <tt>3</tt>

+

| sector-based + central division decomposition

+

| <tt>''X0''</tt>, <tt>''Y0''</tt> and <tt>''α0''</tt> are available, only applicable if MPI-tasks > 4

+

|}

+

Notes:

+

*Domain decomposition works in MPI mode by separating burnable materials into different parallel tasks.

+

*The number of domains is given by the number of MPI tasks.

+

*Only burnable materials separated into depletion zones using the '''sep''' entry in the [[#div|div card]] are decomposed

+

*Decomposed materials are plotted in domain-specific colors (unless the '''rgb''' entry in the [[#mat (material definition)|mat card]] is used)

+

*The domain decomposition methodology is described in a related paper<ref name="dd">Garcia, M., Leppänen, J. and Sanchez-Espinoza, V. ''"A Collision-based Domain Decomposition scheme for large-scale depletion with the Serpent 2 Monte Carlo code."'' Ann. Nucl. Energy, [https://doi.org/10.1016/j.anucene.2020.108026 '''152''' (2021) 108026].</ref>.

+

*For more information, see the detail description and practical example on the [[Domain decomposition|Domain decomposition]].

=== set declib ===

Line 2,594:

Line 4,666:

Notes:

−

*Decay libraries are standard ENDF format files containing decay data.

+

*Decay libraries are standard ENDF format<ref name="endf" /> files containing decay data.

*If the file path contains special characters it is advised to enclose it within quotes.

−

*A default directory path can be set by defining environment variable SERPENT_DATA. The code looks for decay data files in this path if not found at the absolute.

+

*A default directory path can be set by defining environment variable <tt>SERPENT_DATA</tt>. The code looks for decay data files in this path if not found at the absolute.

+

*From version 2.2.0 and on, a default decay data library directory file can be set by defining environment variable <tt>SERPENT_DECLIB</tt>.

+

**This file will be used if no other path is given with '''set declib'''.

+

=== set decomp ===

+

'''set decomp''' ''OPT'' [ ''ELEM1'' ''ELEM2'' ... ]

+

Decomposes elemental entries in material cards into isotopes. Input values:

+

{|

+

| <tt>''OPT''</tt>

+

| : option to include (1) or exclude (0) elements from decomposed list

+

|-

+

| <tt>''ELEMn''</tt>

+

| : element names

+

|}

+

Notes:

+

* Elemental entries are identifed from zero A in ZA.

+

* The decomposition is based on built-in isotope fractions.

+

* If the list is not provided, all elemental entries are decomposed.

=== set delnu ===

Line 2,609:

Line 4,702:

Notes:

−

+

* Default values:

−

*~~Delayed~~ neutron emission is on ~~by default in neutron criticality~~ source ~~and~~ off by ~~default~~ in ~~external source simulation mode~~.

+

** Criticality source mode: the delayed neutron emission is "<tt>on</tt>"

+

** External (static/dynamic) source mode: the delayed neutron emission is "<tt>off</tt>"

+

*In time-dependent calculations, driven by the [[#set dynsrc|set dynsrc]] option, precursor based delayed neutron emission is included in the calculation

+

** "<tt>off</tt>" at fission, but "<tt>on</tt>" at delayed nubar in total nubar.

*See separate description of [[physics options in Serpent]] for differences to other codes.

+

=== set depmtx ===

+

'''set depmtx''' ''MODE''

+

Print burnup matrixes to <tt>[input]_depmtx_[mat]_[bu]_[ss].m</tt> file during burnup calculation, where "<tt>bu</tt>" is the burnup step and "<tt>ss</tt>" is the substep. Input values:

+

{|

+

| <tt>''MODE''</tt>

+

| : option to switch on (1/yes) or off (0/no) the printing of burnup matrixes. The default value is "<tt>off</tt>"

+

|}

+

Notes:

+

*With non-constant predictor, this option will stop the simulation up to version 2.1.31.

+

*With multiple substeps, only the last one is kept after the simulation up to version 2.1.31.

+

*The burnup matrix output is named <tt>depmtx_[mat][bu].m</tt> up to version 2.1.31.

=== set depout ===

−

'''set depout''' ''MODE''

+

'''set depout''' ''MODE'' [''STEP'']

−

Controls which burnable material compositions are printed into the [input]_dep.m output file in case of divided materials. Input values:

+

Controls which burnable material compositions are printed into the <tt>[input]_dep.m</tt> output file in case of divided materials. Input values:

{|

| <tt>''MODE''</tt>

−

| : value indicating, which materials to output to the [input]_dep.m file (1 = only partials, 2 = only parents, 3 = both)

+

| : value indicating, which materials to output to the <tt>[input]_dep.m</tt> file (1 = only partials, 2 = only parents, 3 = both). (default value: 2)

+

|-

+

|<tt>''STEP''</tt>

+

| : value indicating the print-out interval of the <tt>[input]_dep.m</tt> file (0 = final step, 1 = all steps, 2 =none). (default value: 1)

|}

Notes:

*Parent materials refer to materials defined by [[#mat (material definition)|mat cards]], and partials to depletion zones created automatically using the [[#div (divisor definition)|div card]].

−

*~~Default~~ is 2 (~~only parents~~).

+

*Print-out interval step option 2, no <tt>[input]_dep.m</tt> generation, can be combined with post-processing re-depletion: [[Installing and running Serpent#Running Serpent|<tt>''-rdep''</tt>]] command line option.

+

*Combined with the domain decomposition feature ([[#set dd|set dd]] option):

+

**If the mode is different from 2, it generates multiple depletion files which are named adding <tt>_dd[mpiid]</tt> (domain decomposition identifier) to the standard file name.

+

**Each of them contains the partial materials information of the given domain/MPI task.

+

=== set deppara ===

+

'''set deppara''' ''PARAM_LIST''

+

Defines the material- and isotopic-wise variables included in the depletion output file <tt>[input]_dep.m</tt>. Input values:

+

{|

+

| <tt>''PARAM_LIST''</tt>

+

| : list of variables (default value: "<tt>all</tt>")

+

|}

+

Possible key-words/variables are:

+

::{| class="wikitable" style="text-align: left;"

+

! Key-word

+

! Quantity

+

! Output ID

+

! Description

+

|-

+

| <tt>atom</tt>

+

| atom density

+

| <tt>ADENS</tt>

+

| [in b-1cm-1]

+

|-

+

| <tt>mass</tt>

+

| mass density

+

| <tt>MDENS</tt>

+

| [in g/cm3]

+

|-

+

| <tt>activity</tt>

+

| activity

+

| <tt>A</tt>

+

| [in Bq]

+

|-

+

| <tt>dh</tt>

+

| decay heat

+

| <tt>H</tt>

+

| [in W]

+

|-

+

| <tt>sf</tt>

+

| spontaneous fission rate

+

| <tt>SF</tt>

+

| [in fissions/s]

+

|-

+

| <tt>gsrc</tt>

+

| photon emission rate

+

| <tt>GSRC</tt>

+

| [in photons/s]

+

|-

+

| <tt>ingtox</tt>

+

| ingestion toxicity

+

| <tt>ING_TOX</tt>

+

| [in Sv]

+

|-

+

| <tt>inhtox</tt>

+

| inhalation toxicity

+

| <tt>INH_TOX</tt>

+

| [in Sv]

+

|-

+

| <tt>all</tt>

+

|

+

|

+

| include full-set of variables

+

|-

+

| <tt>none</tt>

+

|

+

|

+

| exclude full-set of variables

+

|}

+

Notes:

+

*For more information, see detailed description of the [[Description of output files#Burnup calculation output|burnup calculation output]].

+

=== set depstepbunorm ===

+

'''set depstepbunorm''' ''NORM''

+

Sets the depletion step normalization in burnup calculations based on energy deposition. Input values:

+

{|

+

| <tt>''NORM''</tt>

+

| : depletion step normalization mode based on energy deposition (1 = all materials, 2 = burnable materials)

+

|}

+

Notes

+

* Default values (see [[#set edepmode|set edepmode]]):

+

** For energy deposition modes 0/1: the normalization includes only "<tt>burnable</tt>" materials - mode 2.

+

** For energy deposition modes 2/3: the normalization includes "<tt>all materials</tt>" - mode 1.

=== set dfsol ===

Line 2,632:

Line 4,836:

{|

| <tt>''MODE''</tt>

−

| : boundary conditions for solver (1 = include net currents at boundary surfaces and corners, 2 = include only surface currents)

+

| : boundary conditions for solver (1 = include net currents at boundary surfaces and corners, 2 = include only surface currents). (default value: 1)

|-

| <tt>''DC''</tt>

−

| : type of diffusion coefficient used in the calculation (1 = ~~INF_DIFFCOEF,~~ 2 = ~~TRC_DIFFCOEF~~)

+

| : type of diffusion coefficient used in the calculation (1 = out-scattering 2 = transport correction). (default value: 1)

|-

| <tt>''NP''</tt>

−

| : number of points for trapezoidal integration for homogeneous flux

+

| : number of points for trapezoidal integration for homogeneous flux (default value: 100)

|}

Notes:

−

*This input option is used to control how the deterministic diffusion flux solver used to obtain assembly discontinuity factors [[#set adf|(set adf)]] and pin power distributions [[#set ppw|(set ppw)]] is run.

+

*This input option is used to control how the deterministic diffusion flux solver used to obtain assembly discontinuity factors ([[#set adf|set adf]]) and pin power distributions ([[#set ppw|set ppw]]) is run.

−

*Default mode is 1 (include both surfaces and corners in solution).

+

*The option syntax was revised in update 2.1.27 (<tt>''DC''</tt> option was added between <tt>''MODE''</tt> and <tt>''NP''</tt>).

−

*Default diffusion coefficient is INF_DIFFCOEF, option 2 requires the [[#set trc|set trc]] option.

+

*Deterministic diffusion flux solver use:

−

*Default number of points for trapezoidal integration is 100.

+

**Out-scattering approximation, <tt>INF_DIFFCOEF</tt> and <tt>INF_TRANSPXS</tt>.

−

*See also separate description of the [[Diffusion flux solver|built-in diffusion flux solver]].

+

**Transport correction, <tt>TRC_DIFFCOEF</tt> and <tt>TRC_TRANSPXS</tt>. It requires enabling the [[#set trc|set trc]] option.

−

*The ~~format~~ was revised in update 2.1.27 (<tt>''DC''</tt> option was added between <tt>''MODE''</tt> and <tt>''NP''</tt>).

+

*For more information, see a detailed description on the [[Diffusion flux solver|built-in diffusion flux solver]].

=== set dix ===

'''set dix''' ''OPT''

−

Sets double indexing for cross section energy grid look-up on or off:

+

Sets double indexing for cross section energy grid look-up on or off. Input values:

{|

Line 2,659:

Line 4,863:

Notes:

−

*Double indexing<ref name="dix">Leppänen, J.

+

*Double indexing is a method to speed-up the cross section look-up when energy grid unionization is not used for microscopic data.

−

''"Two practical methods for unionized energy grid construction in continuous-energy Monte Carlo neutron transport calculation."'' Ann. Nucl. Energy [https://www.sciencedirect.com/science/article/pii/S0306454909001108 '''36''' (2009) 878-885].</ref> ~~is a method to speed-up the cross section look-up when energy grid unionization is not used for microscopic data.~~

+

*The method can be used only in optimization modes 1 and 3 (modes 2 and 4 are based on energy grid unionization), see [[#set_opti|set opti]] option.

−

*The method can be used only in [[#set_opti|optimization modes]] 1 and 3 (modes 2 and 4 are based on energy grid unionization).

+

* The methodology is described in related paper<ref name="dix">Leppänen, J.

+

''"Two practical methods for unionized energy grid construction in continuous-energy Monte Carlo neutron transport calculation."'' Ann. Nucl. Energy [https://www.sciencedirect.com/science/article/pii/S0306454909001108 '''36''' (2009) 878-885].</ref>

−

=== set ~~dynsrc~~ ===

+

=== set dspec ===

−

'''set ~~dynsrc~~''' ''~~PATH~~'' [ ''~~MODE~~'' ]

+

'''set dspec''' ''EGRIDp'' ''EGRIDn'

@@ Line 12: / Line 12: @@
 ''"Serpent – a Continuous-energy Monte Carlo Reactor Physics Burnup Calculation Code."'' [http://montecarlo.vtt.fi/download/Serpent_manual.pdf User manual], June 18, 2015.</ref>.
-== Input cards ==
+== Input cards<span id="input cards"></span> ==
 NOTE: Serpent command words are in <tt>'''boldface'''</tt> and input parameters entered by the user in <tt>''CAPITAL ITALIC''</tt>. Optional input parameters are enclosed in [ square brackets ], and when the number of values is not fixed, the remaining values are marked with three dots (...).
@@ Line 18: / Line 18: @@
 === branch (branch definition)<span id="branch"></span> ===
-  '''branch''' ''NAME'' [ '''repm''' ''MAT<sub>1</sub>'' ''MAT<sub>2</sub>'' ]
+  '''branch''' ''NAME'' [ [[#branch_repm|'''repm''']] ''MAT<sub>1</sub>'' ''MAT<sub>2</sub>'' ]
-              [ '''repu''' ''UNI<sub>1</sub>'' ''UNI<sub>2</sub>'' ]
+              [ [[#branch_repu|'''repu''']] ''UNI<sub>1</sub>'' ''UNI<sub>2</sub>'' ]
-              [ '''stp''' ''MAT DENS TEMP THERM<sub>1</sub> SABL<sub>1</sub> SABH<sub>1</sub> THERM<sub>2</sub> SABL<sub>2</sub> SABH<sub>2</sub> ...'' ]
+              [ [[#branch_stp|'''stp''']] ''MAT DENS TEMP THERM<sub>1</sub> SABL<sub>1</sub> SABH<sub>1</sub> THERM<sub>2</sub> SABL<sub>2</sub> SABH<sub>2</sub> ...'' ]
-              [ '''tra''' ''TGT TRANS'' ]
+              [ [[#branch_tra|'''tra''']] ''TGT TRANS'' ]
-              [ '''xenon''' ''OPT'' ]
+              [ [[#branch_xenon|'''xenon''']] ''OPT'' ]
-              [ '''samarium''' ''OPT'' ]
+              [ [[#branch_samarium|'''samarium''']] ''OPT'' ]
-              [ '''var''' ''VNAME VAL'' ]
+              [ [[#branch_norm|'''norm''']] ''NSF'' ]
-Defines the variations invoked for a branch in the automated burnup sequence. Input values:
+             [ [[#branch_gcu|'''gcu''']] ''UNI<sub>2</sub>'' ]
+             [ [[#branch_reptrc|'''reptrc''']] ''FILE<sub>1</sub>'' ''FILE<sub>2</sub>'' ]
+             [ [[#branch_var|'''var''']] ''VNAME VAL'' ]
+             [ [[#branch_incl|'''incl''']] ''MODFILE'' ]
+Defines the variations invoked for a branch in the automated burnup sequence. The first parameter:
 {|
 | <tt>''NAME''</tt>
 | : branch name
-|-
+|}
+The remaining parameters are defined by separate key words followed by the input values.
+<u>Notes:</u>
+*The branch card can be combined with the [[#coef (coefficient matrix definition)|coef card]], [[#hisv (history variation matrix definition)|hisv card]], and [[#casematrix (casematrix definition)| casematrix card]].
+*The branch name identifies the branch <tt>''BR<sub>m,i</sub>''</tt> in the variation matrix defined by the [[#coef (coefficient matrix definition)|coef card]], [[#hisv (history variation matrix definition)|hisv card]], and [[#casematrix (casematrix definition)| casematrix card]].
+*The input parameters consist of a number variations, which are invoked when the branch is applied.
+*A single branch card may include one or several variations.
+*For more information, see detailed description on the [[automated burnup sequence]].
+<u>Variation types:</u>
+Branch material variation (<tt>'''repm'''</tt>):<span id="branch_repm"></span>
+{|
 | <tt>''MAT<sub>1</sub>''</tt>
 | : name of the replaced material
@@ Line 36: / Line 57: @@
 | <tt>''MAT<sub>2</sub>''</tt>
 | : name of the replacing material
-|-
+|}
+<u>Notes:</u>
+*The material variation can be used to replace one material with another, for example, to change coolant boron concentration.
+*The material replacement works as if <tt>''MAT<sub>1</sub>''</tt> were created using the [[#mat_.28material_definition.29|mat]] or [[#mix_.28mixture_definition.29|mix]] card of <tt>''MAT<sub>2</sub>''</tt>.
+*The name of the material present in the geometry will still be <tt>''MAT<sub>1</sub>''</tt> after the replacement, but the material specification (composition, density, tmp, moder, rgb, etc.) will correspond to <tt>''MAT<sub>2</sub>''</tt>.
+**This means that all other input-cards that are linked to a specific material name such as '''dm''' entry in the [[#det_dm|det card]], '''sm''' entry in the [[#src_sm|src card]], [[#set_trc|set trc]] option and/or [[#set_iter_nuc|set iter nuc]] option can be linked to the original material (<tt>''MAT<sub>1</sub>''</tt>) and they will automatically apply to whatever material <tt>''MAT<sub>2</sub>''</tt> replaces <tt>''MAT<sub>1</sub>''</tt> for the branch calculation.
+*The replaced material ''MAT<sub>1</sub>'' is also replaced inside mixtures.
+**This means one can not replace a material with a mixture defined with [[#mix (mixture_definition)|mix card]] containing the replaced material (for example replacing pure water defined with [[#mat (material definition)|mat card]] by a mixture of boron and water defined with a [[#mix (mixture definition)|mix card]] containing the same pure water material).
+*The replacing material ''MAT<sub>2</sub>'' can not be included in the geometry using other cards than the branch card, from version 2.1.30 and on.
+Branch universe variation (<tt>'''repu'''</tt>):<span id="branch_repu"></span>
+{|
 | <tt>''UNI<sub>1</sub>''</tt>
 | : name of the replaced universe
@@ Line 42: / Line 77: @@
 | <tt>''UNI<sub>2</sub>''</tt>
 | : name of the replacing universe
-|-
+|}
+<u>Notes:</u>
+*The universe variation can be used to replace one universe with another, for example, to replace empty control rod guide tubes with rodded tubes for control rod insertion in 2D geometries.
+*The name of the universe present in the geometry will still be <tt>''UNI<sub>1</sub>''</tt> after the replacement, but the universe contents will correspond to <tt>''UNI<sub>2</sub>''</tt>.
+*This means that all other input-cards that are linked to a specific universe name such as '''du''' entry in the [[#det_du|det card]] and/or '''su''' entry in the [[#src_su|src card]] can be linked to the original universe (<tt>''UNI<sub>1</sub>''</tt>) and they will automatically apply to whatever universe <tt>''UNI<sub>2</sub>''</tt> replaces <tt>''UNI<sub>1</sub>''</tt> for the branch calculation.
+Branch state variation, density/temperature (<tt>'''stp'''</tt>):<span id="branch_stp"></span>
+{|
 | <tt>''MAT''</tt>
 | : name of the material for which density and temperature are adjusted
 |-
 | <tt>''DENS''</tt>
-| : material density after adjustment (positive entries for atomic, negative entries for mass densities, or "sum" to use the sum of the constituent nuclide densities)
+| : material density after adjustment (positive value = atomic density [in b<sup>-1</sup>cm<sup>-1</sup>], negative value = mass density [in g/cm<sup>3</sup>])
 |-
 | <tt>''TEMP''</tt>
-| : material temperature after adjustment, or -1 if no adjustment in temperature
+| : material temperature after adjustment [in K]
 |-
 | <tt>''THERM<sub>n</sub>''</tt>
-| : ''n:th'' thermal scattering data associated with the material
+| : ''n''-th thermal scattering data associated with the material
 |-
 | <tt>''SABL<sub>n</sub>''</tt>
-| : name of the ''n'':th S(<math>\alpha,\beta</math>) library for temperature below the given value
+| : name of the ''n''-th S(&alpha;, &beta;) library for temperature below the given value
 |-
 | <tt>''SABH<sub>n</sub>''</tt>
-| : name of the ''n'':th S(<math>\alpha,\beta</math>) library for temperature above the given value
+| : name of the ''n''-th S(&alpha;, &beta;) library for temperature above the given value
-|-
+|}
+<u>Notes:</u>
+*The state variation can be used to change material density and temperature.
+*There is a special entry for the <tt>''TEMP''</tt> parameter:
+**"<tt>-1</tt>": to not adjust temperature
+*There are two special entries for the <tt>''DENS''</tt> parameter:
+** "<tt>sum</tt>": to define the material density as the sum of the constituent nuclides densities (not supported from version 2.2.0 and on)
+** "<tt>original</tt>": to keep unmodified the material density (introduced in version 2.2.1).
+*The adjustment is made using the built-in [[Doppler-broadening preprocessor routine]] and tabular interpolation for S(&alpha;, &beta;) thermal scattering data.
+*The last three parameters of the card are provided only if the material has thermal scattering libraries attached to it (see the [[#therm (thermal scattering library definition)|therm card]]).
+Branch transformation variation (<tt>'''tra'''</tt>):<span id="branch_tra"></span>
+{|
 | <tt>''TGT''</tt>
 | : target universe, surface or cell
@@ Line 66: / Line 125: @@
 | <tt>''TRANS''</tt>
 | : name of the applied transformation
-|-
+|}
+<u>Notes:</u>
+*The transformation variation can be used to move or rotate different parts of the geometry, for example, to adjust the position of control rods in 3D geometries.
+*The name of the transformation <tt>''TRANS''</tt> refers to the unit (universe, cell or surface) entry in the [[#trans (transformations)|trans card]].
+Branch xenon variation (<tt>'''xenon'''</tt>):<span id="branch_xenon"></span>
+{|
 | <tt>''OPT''</tt>
-| : option for setting poison concentrations (0 = set to zero, 1 = use values from restart file)
+| : option for setting xenon poison concentrations (0 = set to zero, 1 = use values from restart file)
+|}
+<u>Notes:</u>
+*The xenon variation can be set to enforced the Xe-135 and Xe-135m concentrations and optionally I-135 concentration to zero.
+**By default the concentrations are read from the restart file.
+*Equilibrium xenon ([[#set_xenon|set xenon]] option).
+**If the calculation is "<tt>on</tt>", then the option "<tt>0</tt>" sets I-135, Xe-135 and Xe-135m concentrations to zero.
+**If the calculation is "<tt>off</tt>", then the option "<tt>0</tt>" sets only Xe-135 and Xe-135m concentrations to zero.
+Branch samarium variation (<tt>'''samarium'''</tt>):<span id="branch_samarium"></span>
+{|
+| <tt>''OPT''</tt>
+| : option for setting samarium poison concentrations (0 = set to zero, 1 = use values from restart file)
+|}
+<u>Notes:</u>
+*The samarium variation can be set to enforce the Sm-149 concentration and possibly Pm-149 concentration to zero.
+**By default the concentrations are read from the restart file.
+*Equilibrium samarium ([[#set_samarium|set samarium]] option):
+**If the calculation is "<tt>on</tt>", then the option "<tt>0</tt>" sets both Pm-149 and Sm-149 concentrations to zero.
+**If the calculation is "<tt>off</tt>", then the option "<tt>0</tt>" sets only Sm-149 concentration to zero.
+Branch normalization variation (<tt>'''nsf'''</tt>):<span id="branch_nsf"></span>
+{|
+| <tt>''NSF''</tt>
+| : normalization scaling factor
+|}
+<u>Notes:</u>
+*The normalization variation can be used to change the normalization.
+*The adjustment is made applying the parameter ''NSF'' as a multiplicative scaling factor to the given normalization.
+Branch group constant variation (<tt>'''gcu'''</tt>):<span id="branch_gcu"></span>
+{|
+| <tt>''UNI<sub>2</sub>''</tt>
+|: name of the replacing universe
+|}
+<u>Notes:</u>
+*The group constant variation can be used to replace the universe for group constant generation.
+*The variation is limited to a single-valued GCU-list (see [[#set gcu|set gcu]] option).
+Branch transport-correction variation (<tt>'''reptrc'''</tt>):<span id="branch_reptrc"></span>
+{|
+| <tt>''FILE<sub>1</sub>''</tt>
+| : file path of the replaced transport correction curve data
 |-
+| <tt>''FILE<sub>2</sub>''</tt>
+| : file path of the replacing transport correction curve data
+|}
+<u>Notes:</u>
+*The transport-correction variation can be used to replace a transport correction file with another (see [[#set trc|set trc]] option).
+Branch variable variation (<tt>'''var'''</tt>):<span id="branch_var"></span>
+{|
 | <tt>''VNAME''</tt>
 | : variable name
@@ Line 78: / Line 211: @@
 <u>Notes:</u>
+*The variable variation can be used to pass information into the output file, which may be convenient for the post-processing of the data.
-*The branch name identifies the branch in the coefficient matrix of the [[#coef (coefficient matrix definition)|coef card]]
-*The input parameters consist of a number variations, which are invoked when the branch is applied. A single branch card may inclued one or several variations.
-*The '''repm''' variation can be used to replace one material with another, for example, to change coolant boron concentration.
-*The '''repu''' variation can be used to replace one universe with another, for example, to replace empty control rod guide tubes with rodded tubes for control rod insertion in 2D geometries.
-*The '''stp''' variation can be used to change material density and temperature. The adjustment is made using the built-in [[Doppler-broadening preprocessor routine]] and tabular interpolation for S(<math>\alpha,\beta</math>) thermal scattering data.
-*The last three parameters of the '''stp''' entry are provided only if the material has thermal scattering libraries attached to it (see the [[#therm (thermal scattering library definition)|therm card]]).
-*The '''tra''' variation can be used to move or rotate different parts of the geometry, for example, to adjust the position of control rods in 3D geometries. The name of the transformation refers to the unit (universe, cell or surface) entry in the [[#trans (transformations)|trans card]].
-*The '''xenon''' and '''samarium''' options can be set to enforce the concentrations of fission product poisons Xe-135 and Sm-149 to zero. By default the concentrations are read from the restart file.
-*Variables can be used to pass information into output file, which may be convenient for the post-processing of the data.
-*The branch card is used together with the [[#coef (coefficient matrix definition)|coef card]].
-*For more information, see detailed description on the [[automated burnup sequence]].
-*The replaced material MAT<sub>1</sub> of repm variation is also replaced inside mixtures. This means one can not replace a material with a mixture defined with [[#mix (mixture_definition)|mix card]] containing the replaced material (for example replacing pure water defined with mat card by a mixture of boron and water defined with a mix card containing the same pure water material).
-*Currently (version 2.1.30) the replacing material MAT<sub>2</sub> of repm variation can not be included in geometry using other cards than the branch card with the repm variation.
-=== cell (cell definition)<span id="cell"></span> ===
+Branch user-defined variation (<tt>'''incl'''</tt>):<span id="branch_incl"></span>
+{|
+| <tt>''MODFILE''</tt>
+|: file path to an additional/modified input file
+|}
- '''cell''' ''NAME UNI<sub>0</sub> MAT'' [ ''SURF<sub>1</sub>'' ''SURF<sub>2</sub>'' ... ]
+<u>Notes:</u>
+*The user-defined variation can be used as a multi-purpose option to modify the base-input via the additional input file <tt>''MODFILE''</tt>.
-Defines a material cell. Input values:
+=== casematrix (casematrix definition)<span id="casematrix"></span> ===
+ '''casematrix''' ''CASE_NAME''
+            ''NHIS'' [ ''HIS_BR<sub>1</sub>'' ''HIS_BR<sub>2</sub>'' ... ''HIS_BR<sub>NHIS</sub>'' ]
+            ''NBU''  [ ''BU<sub>1</sub>'' ''BU<sub>2</sub>'' ... ''BU<sub>NBU</sub>'' ]
+            ''NBR<sub>1</sub>'' [ ''BR<sub>1,1</sub>'' ''BR<sub>1,2</sub>'' ... ''BR<sub>1,NBR<sub>1</sub></sub>'' ]
+            ''NBR<sub>2</sub>'' [ ''BR<sub>2,1</sub>'' ''BR<sub>2,2</sub>'' ... ''BR<sub>1,NBR<sub>2</sub></sub>'' ]
+            ...
+Defines the casematrix for the automated burnup sequence. Input values:
 {|
-| <tt>''NAME''</tt>
+| <tt>''CASE_NAME''</tt>
-| : cell name
+| : name of the casematrix
 |-
-| <tt>''UNI<sub>0</sub>''</tt>
+| <tt>''NHIS''</tt>
-| : universe where the cell belongs to
+| : number of history variations
 |-
-| <tt>''MAT''</tt>
+| <tt>''HIS_BR<sub>k</sub>''</tt>
-| : material that fills the cell
+| : name of the ''k''-th history variation branch
 |-
-| <tt>''SURF<sub>n</sub>''</tt>
+| <tt>''NBU''</tt>
-| : surface list
+| : number of burnup points
-|}
- '''cell''' ''NAME UNI<sub>0</sub>'' '''fill''' ''UNI<sub>1</sub>'' [ ''SURF<sub>1</sub>'' ''SURF<sub>2</sub>'' ... ]
-Defines a filled cell. Input values:
-{|
-| <tt>''NAME''</tt>
-| : cell name
 |-
-| <tt>''UNI<sub>0</sub>''</tt>
+| <tt>''BU<sub>n</sub>''</tt>
-| : universe where the cell belongs to
+| : burnup steps at which the momentary variation branches are invoked (positive value = burnup [in MWd/kg], negative value = time [in d])
 |-
-| <tt>''UNI<sub>1</sub>''</tt>
+| <tt>''NBR<sub>m</sub>''</tt>
-| : universe that fills the cell
+| : number branches in the ''m''-th dimension of the burnup matrix
 |-
-| <tt>''SURF<sub>n</sub>''</tt>
+| <tt>''BR<sub>m,i</sub>''</tt>
-| : surface list
+| : name of the ''i''-th branch in the ''m''-th dimension
 |}
- '''cell''' ''NAME UNI<sub>0</sub>'' '''outside''' [ ''SURF<sub>1</sub>'' ''SURF<sub>2</sub>'' ... ]
+<u>Notes:</u>
+*The casematrix card performs multiple depletions with <tt>''NHIS''</tt> (different) historical variations and performs restarts similar as the [[#coef|coef]] input card.
+*The casematrix card creates a multi-dimensional coefficient matrix (of size <tt>''NBR<sub>1</sub>''</tt> &times; <tt>''NBR<sub>2</sub>''</tt> &times; <tt>''NBR<sub>3</sub>''</tt> &times; ... ).
+**The automated burnup sequence performs a restart for each of the listed burnup points, and loops over the branch combinations defined by the coefficient matrix.
+**This is repeated for each different depletion history.
+*The casematrix card is used together with the [[#branch (branch definition)|branch card]] and [[Installing_and_running_Serpent#Running_casematrix_calculations|<tt>''-casematrix''</tt>]] command line option.
+*Multiple casematrix cards can be given in a single input file.
+*For more information, see detailed description on [[automated burnup sequence]].
+=== cell (cell definition)<span id="cell"></span> ===
+ '''cell''' ''NAME UNI<sub>0</sub> MAT'' [ ''SURF<sub>1</sub>'' ''SURF<sub>2</sub>'' ... ]
-Defines an outside cell. Input values:
+Defines a cell. Input values:
 {|
@@ Line 142: / Line 280: @@
 | <tt>''UNI<sub>0</sub>''</tt>
 | : universe where the cell belongs to
+|-
+| <tt>''MAT''</tt>
+| : material that fills the cell
 |-
 | <tt>''SURF<sub>n</sub>''</tt>
@@ Line 148: / Line 289: @@
 <u>Notes:</u>
+*The cell definition is based on the universe-based geometry type in Serpent.
-*There are three types of cells: material cells, filled cells and outside cells. Filled cells are identified by providing the key word <tt>'''fill'''</tt>, followed by the universe filling the cell. If the key word is missing, the third entry is interpreted as the material filling the cell. Outside cells are identified by replacing the material name with key word <tt>'''outside'''</tt>.
+*Universes are implicitly declared, e.g., by using the <tt>''UNI<sub>0</sub>''</tt> key word on cell cards, as there is no explicit universe input card.
-*Void cells can be defined by setting the material name to "void"
+*The surface list defines the boundaries of the cell by listing the surface names (as provided in the surface definition, [[#surf (surface definition)|surf card]]), together with the operator identifiers (nothing for intersection, ":" for union, "-" for complement and "#" for cell complement).
+*The general cell definition (so-called "material cell") have tailored types, defined by special material entries (replacing <tt>''MAT''</tt>):
+::{| class="wikitable" style="text-align: left;"
+! Type
+! Description
+|-
+| <tt>void</tt>
+| region is defined as zero-collision
+|-
+| <tt>fill ''UNI<sub>1</sub>''</tt>
+| region is filled by another universe, <tt>''UNI<sub>1</sub>''</tt>
+|-
+| <tt>outside</tt>
+| region is not part of the actual geometry ("outside world")
+|-
+|}
+::Outside cells:
+::*When the particle enters an outside cell, the boundary conditions are applied (see [[#set bc|set bc]] option). It is important that the geometry model is non-re-entrant (convex) when vacuum boundary conditions are used. Delta-tracking might miss the boundary conditions in a re-entrant (concave) outer surface.
+::*Outside cells are allowed only in the root universe. It is important that all space outside the model is defined.
+*Cells defined without surfaces are treated as infinite, from version 2.1.32 on.
 *When the geometry is set up, the root universe must always be defined. By default the root universe is named "0", and it can be changed with the [[#set root|set root]] option.
-*Outside cells are used to define the part of the geometry that does not belong to the model. When the particle enters an outside cell, [[#set bc|boundary conditions]] are applied. It is important that the geometry model is non-re-entrant when vacuum boundary conditions are used.
-*Outside cells are allowed only in the root universe. It is important that all space outside the model is defined.
-*The surface list defines the boundaries of the cell by listing the surface names (as provided in the [[#surf (surface definition)|surface card]]), together with the operator identifiers (nothing for intersection, ":" for union, "-" for complement and "#" for cell complement).
-*Universes are implicitly declared for example by using the <tt>''UNI<sub>0</sub>''</tt> key words on cell cards as there is no explicit universe input card.
 *For more information, see detailed description on the [[universe-based geometry type in Serpent]].
@@ Line 171: / Line 327: @@
 |-
 | <tt>''BU<sub>n</sub>''</tt>
-| : burnup steps at which the branches are invoked
+| : burnup steps at which the branches are invoked (positive value = burnup [in MWd/kg], negative value = time [in d])
 |-
 | <tt>''NBR<sub>m</sub>''</tt>
-| : number branches in the ''m'':th dimension of the burnup matrix
+| : number branches in the ''m''-th dimension of the burnup matrix
 |-
 | <tt>''BR<sub>m,i</sub>''</tt>
-| : name of the ''i'':th branch in the ''m'':th dimension
+| : name of the ''i''-th branch in the ''m''-th dimension
 |}
 <u>Notes:</u>
-*The coef card creates a multi-dimensional coefficient matrix (of size <tt>''NBR<sub>1</sub>''</tt> <math>\times</math> <tt>''NBR<sub>2</sub>''</tt> <math>\times</math> <tt>''NBR<sub>3</sub>''</tt> <math>\times</math> ... ). The automated burnup sequence performs a restart for each of the listed burnup points, and loops over the branch combinations defined by the coefficient matrix.
+*The coef card creates a multi-dimensional coefficient matrix (of size <tt>''NBR<sub>1</sub>''</tt> &times; <tt>''NBR<sub>2</sub>''</tt> &times; <tt>''NBR<sub>3</sub>''</tt> &times; ... ).
-*Positive values in the burnup vector are interpreted as (MWd/kgU), negative values are interpreted as time steps in days.
+**The automated burnup sequence performs a restart for each of the listed burnup points, and loops over the branch combinations defined by the coefficient matrix.
-*The coef card is used together with the [[#branch (branch definition)|branch card]]
+*The coef card is used together with the [[#branch (branch definition)|branch]] card.
+*For multiple historical variations or historical conditions defined using a [[#branch (branch definition)|branch]] card, see the [[#casematrix (casematrix definition)|casematrix]] card.
 *For more information, see detailed description on [[automated burnup sequence]].
+=== datamesh (general data mesh definition)<span id="datamesh"></span> ===
+ '''datamesh''' ''NAME'' ''TYPE'' ''USE<sub>LC</sub>'' [ ... ]
+Defines a general data mesh to be used for spacial discretisation. Input values:
+{|
+| <tt>''NAME''</tt>
+| : mesh name
+|-
+| <tt>''TYPE''</tt>
+| : mesh type
+|-
+| <tt>''USE<sub>LC</sub>''</tt>
+| : use lowest level coordinates (1/yes) instead of global coordinates (0/no) for the mesh search
+|-
+|}
+The remaining parameters are type-dependent.
+<u>Notes:</u>
+*The general data mesh can be used, e.g.,  with detectors ('''dmesh''' entry in the [[#det|det card]]), interfaces ([[#ifc|ifc card]]), sensitivities ('''opt dmesh''' entry in the [[#sens|sens card]]), etc.
+*When Serpent makes the mesh search for a specific collision point, it will save the collision mesh cell temporarily so that the cell search is conducted at most once even when scoring multiple estimators using the same mesh.
+*The nested data meshes (type 9) take the coordinates' level from the <tt>''USE<sub>LC</sub>''</tt> parameter defined in the nested mesh itself and use it in the subsequent sub-meshes, overriding the <tt>''USE<sub>LC</sub>''</tt> parameter defined on those.
+The available <u>general data mesh types</u> are:
+::{| class="wikitable" style="text-align: left;"
+! Type
+! Description
+|-
+| [[#datamesh_1|<tt>1</tt>]]
+| regular 3D Cartesian mesh
+|-
+| [[#datamesh_2|<tt>2</tt>]]
+| regular 2D cylindrical mesh
+|-
+| [[#datamesh_4|<tt>4</tt>]]
+| regular 3D X-type hexagonal mesh
+|-
+| [[#datamesh_5|<tt>5</tt>]]
+| regular 3D Y-type hexagonal mesh
+|-
+| [[#datamesh_6|<tt>6</tt>]]
+| irregular 3D Cartesian mesh
+|-
+| [[#datamesh_8|<tt>8</tt>]]
+| radially irregular 2D cylindrical mesh
+|-
+| [[#datamesh_9|<tt>9</tt>]]
+| regular nested mesh
+|-
+|}
+The syntax of the available types is as follows:
+ '''datamesh''' ''NAME'' '''1''' ''USE<sub>LC</sub>'' ''N<sub>X</sub>'' ''X<sub>MIN</sub>'' ''X<sub>MAX</sub>'' ''N<sub>Y</sub>'' ''Y<sub>MIN</sub>'' ''Y<sub>MAX</sub>'' ''N<sub>Z</sub>'' ''Z<sub>MIN</sub>'' ''Z<sub>MAX</sub>'' <span id="datamesh_1"></span>
+{|
+| <tt>''N<sub>X</sub>''</tt>
+| : number of cells in the x-direction
+|-
+| <tt>''X<sub>MIN</sub>''</tt>
+| : mesh lower x-boundary [in cm]
+|-
+| <tt>''X<sub>MAX</sub>''</tt>
+| : mesh higher x-boundary [in cm]
+|-
+| <tt>''N<sub>Y</sub>''</tt>
+| : number of cells in the y-direction
+|-
+| <tt>''Y<sub>MIN</sub>''</tt>
+| : mesh lower y-boundary [in cm]
+|-
+| <tt>''Y<sub>MAX</sub>''</tt>
+| : mesh higher y-boundary [in cm]
+|-
+| <tt>''N<sub>Z</sub>''</tt>
+| : number of cells in the z-direction
+|-
+| <tt>''Z<sub>MIN</sub>''</tt>
+| : mesh lower z-boundary [in cm]
+|-
+| <tt>''Z<sub>MAX</sub>''</tt>
+| : mesh higher z-boundary [in cm]
+|}
+ '''datamesh''' ''NAME'' '''2''' ''USE<sub>LC</sub>'' ''N<sub>R</sub>'' ''R<sub>MIN</sub>'' ''R<sub>MAX</sub>'' ''N<sub>PHI</sub>'' <span id="datamesh_2"></span>
+{|
+| <tt>''N<sub>R</sub>''</tt>
+| : number of cells in the radial direction
+|-
+| <tt>''R<sub>MIN</sub>''</tt>
+| : mesh inner radial boundary [in cm]
+|-
+| <tt>''R<sub>MAX</sub>''</tt>
+| : mesh outer radial boundary [in cm]
+|-
+| <tt>''N<sub>PHI</sub>''</tt>
+| : number of cells in the polar angle direction
+|}
+[[File:Hex lattice x index.png|frame|X-type hexagonal mesh horizontal indexing example for N<sub>X</sub> = N<sub>Y</sub> = 3.]]
+ '''datamesh''' ''NAME'' '''4''' ''USE<sub>LC</sub>'' ''X<sub>0</sub>'' ''Y<sub>0</sub>'' ''PITCH'' ''Z<sub>MIN</sub>'' ''Z<sub>MAX</sub>'' ''N<sub>X</sub>'' ''N<sub>Y</sub>'' ''N<sub>Z</sub>'' <span id="datamesh_4"></span>
+{|
+| <tt>''X<sub>0</sub>''</tt>
+| : mesh horizontal origin x-coordinate [in cm]
+|-
+| <tt>''Y<sub>0</sub>''</tt>
+| : mesh horizontal origin y-coordinate [in cm]
+|-
+| <tt>''PITCH''</tt>
+| : mesh horizontal pitch (equal to cell flat-to-flat width) [in cm]
+|-
+| <tt>''Z<sub>MIN</sub>''</tt>
+| : mesh lower z-boundary [in cm]
+|-
+| <tt>''Z<sub>MAX</sub>''</tt>
+| : mesh higher z-boundary [in cm]
+|-
+| <tt>''N<sub>X</sub>''</tt>
+| : number of cells in the x-direction
+|-
+| <tt>''N<sub>Y</sub>''</tt>
+| : number of cells in the y-direction
+|-
+| <tt>''N<sub>Z</sub>''</tt>
+| : number of cells in the z-direction
+|}
+[[File:Hex lattice y index.png|frame|Y-type hexagonal mesh horizontal indexing example for N<sub>X</sub> = N<sub>Y</sub> = 3.]]
+ '''datamesh''' ''NAME'' '''5''' ''USE<sub>LC</sub>'' ''X<sub>0</sub>'' ''Y<sub>0</sub>'' ''PITCH'' ''Z<sub>MIN</sub>'' ''Z<sub>MAX</sub>'' ''N<sub>X</sub>'' ''N<sub>Y</sub>'' ''N<sub>Z</sub>'' <span id="datamesh_5"></span>
+{|
+| <tt>''X<sub>0</sub>''</tt>
+| : mesh horizontal origin x-coordinate [in cm]
+|-
+| <tt>''Y<sub>0</sub>''</tt>
+| : mesh horizontal origin y-coordinate [in cm]
+|-
+| <tt>''PITCH''</tt>
+| : mesh horizontal pitch (equal to cell flat-to-flat width) [in cm]
+|-
+| <tt>''Z<sub>MIN</sub>''</tt>
+| : mesh lower z-boundary [in cm]
+|-
+| <tt>''Z<sub>MAX</sub>''</tt>
+| : mesh higher z-boundary [in cm]
+|-
+| <tt>''N<sub>X</sub>''</tt>
+| : number of cells in the x-direction
+|-
+| <tt>''N<sub>Y</sub>''</tt>
+| : number of cells in the y-direction
+|-
+| <tt>''N<sub>Z</sub>''</tt>
+| : number of cells in the z-direction
+|}
+ '''datamesh''' ''NAME'' '''6''' ''USE<sub>LC</sub>'' ''N<sub>X</sub>'' ''N<sub>Y</sub>'' ''N<sub>Z</sub>''  ''X<sub>1</sub>'' ... ''X<sub>N<sub>X</sub>+1</sub>''  ''Y<sub>1</sub>'' ... ''Y<sub>N<sub>Y</sub>+1</sub>''  ''Z<sub>1</sub>'' ... ''Z<sub>N<sub>Z</sub>+1</sub>'' <span id="datamesh_6"></span>
+{|
+| <tt>''N<sub>X</sub>''</tt>
+| : number of cells in the x-direction
+|-
+| <tt>''N<sub>Y</sub>''</tt>
+| : number of cells in the y-direction
+|-
+| <tt>''N<sub>Z</sub>''</tt>
+| : number of cells in the z-direction
+|-
+| <tt>''X<sub>i</sub>''</tt>
+| : <tt>''N<sub>X</sub>'' + 1</tt> mesh boundaries in the x-direction [in cm]
+|-
+| <tt>''Y<sub>i</sub>''</tt>
+| : <tt>''N<sub>Y</sub>'' + 1</tt> mesh boundaries in the y-direction [in cm]
+|-
+| <tt>''Z<sub>i</sub>''</tt>
+| : <tt>''N<sub>Z</sub>'' + 1</tt> mesh boundaries in the z-direction [in cm]
+|}
+ '''datamesh''' ''NAME'' '''8''' ''USE<sub>LC</sub>'' ''N<sub>R</sub>'' ''N<sub>PHI</sub>''  ''R<sub>1</sub>'' ... ''R<sub>N<sub>R</sub>+1</sub>'' <span id="datamesh_8"></span>
+{|
+| <tt>''N<sub>R</sub>''</tt>
+| : number of cells in the radial direction
+|-
+| <tt>''N<sub>PHI</sub>''</tt>
+| : number of cells in the polar angle direction
+|-
+| <tt>''R<sub>i</sub>''</tt>
+| : <tt>''N<sub>R</sub>'' + 1</tt> mesh boundaries in the radial direction [in cm]
+|}
+ '''datamesh''' ''NAME'' '''9''' ''USE<sub>LC</sub>'' ''N<sub>LEVEL</sub>''  ''MESH<sub>1</sub>'' ... ''MESH<sub>N<sub>LEVEL</sub></sub>'' <span id="datamesh_9"></span>
+{|
+| <tt>''N<sub>LEVEL</sub>''</tt>
+| : number of nested levels in this mesh
+|-
+| <tt>''MESH<sub>i</sub>''</tt>
+| : sub mesh to use at level ''i''
+|}
 === dep (depletion history)<span id="dep"></span> ===
@@ Line 202: / Line 566: @@
 The possible step types are:
-{| class="wikitable" style="text-align: left;"
+::{| class="wikitable" style="text-align: left;"
 ! Type
 ! Description
@@ Line 250: / Line 614: @@
 <u>Notes:</u>
-*Transport cycle is omitted with the <tt>decstep</tt> and <tt>dectot</tt> options.
+*Depletion calculations (burnup/activation steps) require normalization.
-*Transport cycle is run only once with the <tt>actstep</tt> and <tt>acttot</tt> options.
+**See: [[#set power|set power]], [[#set powdens|set powdens]], [[#set flux|set flux]], [[#set genrate|set genrate]], [[#set fissrate|set fissrate]], [[#set absrate|set absrate]], [[#set lossrate|set lossrate]], [[#set srcrate|set srcrate]], [[#set sfrate|set sfrate]].
+**If the normalization is set to zero, physical estimates, e.g., detectors will be printed as zero.
+***Alternatively, use a very small value to enforce a non-zero normalization.
+**Except:
+***Radioactive decay source: source rate normalization is carried out automatically based on the total emission rate.
+***Decay steps: equivalent, e.g., zero power.
+*Activation step, "<tt>actstep</tt>" and "<tt>acttot</tt>":
+**Transport cycle is run only once and transmutation cross sections are not updated.
+**Limitations:
+***It must be preceeded by a burnup step.
+***It cannot be used with a burnable material radioactive source.
+***Burnup is not calculated correctly
+*Decay step, "<tt>decstep</tt>" and "<tt>dectot</tt>":
+**Transport cycle is omitted and transmutation cross sections are not calculated.
+**Limitations:
+***It cannot preceed activation steps.
+***Physical estimates, e.g., detectors will not be printed for the given step (value zero) due to normalization
-  '''dep''' '''pro''' ''PTR_REPROC''
+  '''dep''' '''pro''' ''REP_NAME'' ''STYPE'' [ ''STEP<sub>1</sub> STEP<sub>2</sub> ...'' ]
+Links a reprocessor to the depletion calculation. Input values:
+{|
+| <tt>''REP_NAME''</tt>
+| : reprocessor name
+|-
+| <tt>''STYPE''</tt>
+| : step type
+|-
+| <tt>''STEP<sub>n</sub>''</tt>
+| : depletion step list
+|}
+<u>Notes:</u>
+*The reprocessing system or reprocessor controller is defined using the [[#rep|rep card]].
   '''dep''' '''bra''' ''PTR_BRANCH''
@@ Line 269: / Line 665: @@
            [ [[#det_dy|'''dy''']] ''Y<sub>MIN</sub>'' ''Y<sub>MAX</sub>'' ''N<sub>Y</sub>'' ]
            [ [[#det_dz|'''dz''']] ''Z<sub>MIN</sub>'' ''Z<sub>MAX</sub>'' ''N<sub>Z</sub>'' ]
-           [ [[#det_dn|'''dn''']] ''TYPE'' ''MIN<sub>1</sub>'' ''MAX<sub>1</sub>'' ''N<sub>1</sub>'' ''MIN<sub>2</sub>'' ''MAX<sub>2</sub>'' ''N<sub>2</sub>'' ''MIN<sub>3</sub>'' ''MAX<sub>3</sub>'' ''N<sub>3</sub>'' ]
+           [ [[#det_dn1|'''dn''']] ''TYPE'' ''MIN<sub>1</sub>'' ''MAX<sub>1</sub>'' ''N<sub>1</sub>'' ''MIN<sub>2</sub>'' ''MAX<sub>2</sub>'' ''N<sub>2</sub>'' ''MIN<sub>3</sub>'' ''MAX<sub>3</sub>'' ''N<sub>3</sub>'' ]
+          [ [[#det_dn2|'''dn''']] ''TYPE'' ''N<sub>1</sub>'' ''N<sub>2</sub>'' ''N<sub>3</sub>'' ''LIM<sub>11</sub>''...''LIM<sub>1N+1</sub>'' ''LIM<sub>21</sub>''...''LIM<sub>2N+1</sub>'' ''LIM<sub>31</sub>''...''LIM<sub>3N+1</sub>'' ]
            [ [[#det_dh|'''dh''']] ''TYPE'' ''X<sub>0</sub>'' ''Y<sub>0</sub>'' ''PITCH'' ''N<sub>1</sub>'' ''N<sub>2</sub>'' ''Z<sub>MIN</sub>'' ''Z<sub>MAX</sub>'' ''N<sub>Z</sub>'' ]
            [ [[#det_dumsh|'''dumsh''']] ''UNI'' ''N<sub>C</sub>'' ''CELL<sub>0</sub>'' ''BIN<sub>0</sub>'' ''CELL<sub>1</sub>'' ''BIN<sub>1</sub>'' ... ]
@@ Line 283: / Line 680: @@
            [ [[#det_da|'''da''']] ''MAT'' ''FLX'' ]
            [ [[#det_dfet|'''dfet''']] ''TYPE'' ''PARAMS'' ]
-Detector definition. The first parameter:
+          [ [[#det_dphb|'''dphb''']] ''PHB'' ]
+          [ [[#det_dmesh|'''dmesh''']] ''MESH'' ]
+Detector definition. The two first parameters:
 {|
+| <tt>''NAME''</tt>
+| : detector name
+|-
 | <tt>''PART''</tt>
 | : particle type (n = neutron, p = photon)
 |}
-is optional in single particle simulations. The remaining parameters are defined by separate key words followed by the input values.
+The remaining parameters are defined by separate key words followed by the input values.
+<u>Notes:</u>
+*The particle type <tt>''PART''</tt> is optional in single particle simulations.
+*The detectors estimates are integrated values over the space, angle, energy and time domains.
+*A detector with an associated discretization in space, angle, energy and/or time turns into multiple bins. Each bin results are correspondingly integrated over the discretization domain.
+*A single detector card may include one or several detector types. If multiple detectors are defined, the results are correspondingly divided into multiple bins.
+<u>Detector types:</u>
 Detector response (<tt>'''dr'''</tt>):<span id="det_dr"></span>
@@ Line 300: / Line 710: @@
 |-
 | <tt>''MAT''</tt>
-| : material name or "<tt>VOID</tt>" if the material at the collision point is used
+| : response associated material name
 |}
@@ Line 306: / Line 716: @@
 *If the detector is assigned with multiple responses, the results are divided correspondingly into separate bins.
 *The response numbers are [[ENDF reaction MT's and macroscopic reaction numbers|ENDF reaction MT's and special reaction types]].
-*Positive response numbers are associated with microscopic cross sections and the result is independent of material density. Materials for microscopic cross sections must consist of a single nuclide.
+**Positive response numbers:
-*Microscopic reactions to ground and isomeric states can be calculated by adding "g" or "m" at the end of the reaction number (e.g. 102g and 102m refer to radiative capture to ground and isomeric states, respectively). This option is available only for nuclides with [[#set_bralib|branching ratios]].
+*** They are associated with microscopic cross sections
-*Negative response numbers are associated with macroscopic cross sections and special types, and the result is multiplied by material density.
+*** The detector result is independent of the material density.
-*The response material in the <tt>'''dr'''</tt> entry must not be confused with the material in the <tt>'''dm'''</tt> entry. The former defines the material for the response function, while the latter determines the volume of integration.
+*** Materials associated to microscopic cross sections must consist of a single nuclide.
+***Microscopic reactions to ground and isomeric states can be calculated by adding "<tt>g</tt>" or "<tt>m</tt>" at the end of the reaction number.
+****E.g. 102g and 102m refer to radiative capture to ground and isomeric states, respectively.
+****This option is available only for nuclides with [[#set_bralib|branching ratios]].
+**Negative response numbers:
+*** They are associated with macroscopic cross sections and special types
+*** The detector result is multiplied by material density
+*The response material in the <tt>'''dr'''</tt> entry must not be confused with the material in the <tt>'''dm'''</tt> entry.
+** The former defines the material for the response function, while the latter determines the volume of integration.
+**There is a special entry for the response associated material:
+*** "<tt>void</tt>": to allow the response not to be pre-assigned with a specific material.
+**** When the detector scores in a collision, the cross-section is taken from the material at the collision point.
+**** Use, e.g., to calculate  integral reaction rates over regions composed of multiple materials.
+**** It only can be used with negative response numbers.
 *By default, Serpent allows a detector to have at most 10,000,000 bins.
@@ Line 317: / Line 740: @@
 {|
 | <tt>''VOL''</tt>
-| : volume in cm<sup>3</sup> (3D geometry) or cross-sectional area in cm<sup>2</sup> (2D geometry)
+| : volume [in cm<sup>3</sup>] (3D geometry) or cross-sectional area [in cm<sup>2</sup>] (2D geometry)
 |}
 <u>Notes:</u>
-*The results are divided by detector volume, which is by default set to 1.
+*The results are divided by detector bin-volume (default value: 1.0)
+*In the case of surface detectors, ''VOL'' represents the surface area [in cm<sup>2</sup>] (3D geometry) or the surface length [in cm] (2D geometry).
@@ Line 354: / Line 778: @@
 <u>Notes:</u>
+*There is a special entry for the material name:
+**"<tt>fiss</tt>": to score only in fissile region(s)
 *If multiple detector materials are defined, the results are correspondingly divided into multiple bins.
 *The material entry defines the volume of integration, which must not be confused with the response material in the <tt>'''dr'''</tt> entry.
@@ Line 369: / Line 795: @@
-Cartesian mesh detector (<tt>'''dx'''</tt>, <tt>'''dy'''</tt> and <tt>'''dz'''</tt>):<span id="det_dx"></span><span id="det_dy"></span><span id="det_dz"></span>
+Detector evenly-spaced Cartesian mesh (<tt>'''dx'''</tt>, <tt>'''dy'''</tt> and <tt>'''dz'''</tt>):<span id="det_dx"></span><span id="det_dy"></span><span id="det_dz"></span>
 {|
 | <tt>''X<sub>MIN</sub>''</tt>
-| : minimum x-coordinate of the detector mesh
+| : minimum x-coordinate of the detector mesh [in cm]
 |-
 | <tt>''X<sub>MAX</sub>''</tt>
-| : maximum x-coordinate of the detector mesh
+| : maximum x-coordinate of the detector mesh [in cm]
 |-
 | <tt>''N<sub>X</sub>''</tt>
@@ Line 382: / Line 808: @@
 |-
 | <tt>''Y<sub>MIN</sub>''</tt>
-| : minimum y-coordinate of the detector mesh
+| : minimum y-coordinate of the detector mesh [in cm]
 |-
 | <tt>''Y<sub>MAX</sub>''</tt>
-| : maximum y-coordinate of the detector mesh
+| : maximum y-coordinate of the detector mesh [in cm]
 |-
 | <tt>''N<sub>Y</sub>''</tt>
@@ Line 391: / Line 817: @@
 |-
 | <tt>''Z<sub>MIN</sub>''</tt>
-| : minimum z-coordinate of the detector mesh
+| : minimum z-coordinate of the detector mesh [in cm]
 |-
 | <tt>''Z<sub>MAX</sub>''</tt>
-| : maximum z-coordinate of the detector mesh
+| : maximum z-coordinate of the detector mesh [in cm]
 |-
 | <tt>''N<sub>Z</sub>''</tt>
@@ Line 401: / Line 827: @@
 <u>Notes:</u>
-*The mesh detectors can be used to sub-divide the results into multiple spatial bins. For a Cartesian mesh the division is provided with separate entries in x-, y- and z- locations.
+*The mesh detectors can be used to sub-divide the results into multiple evenly-spaced bins.
+*For a Cartesian mesh the division is provided with separate entries in x-, y- and z- locations (<tt>'''dx'''</tt>, <tt>'''dy'''</tt> and <tt>'''dz'''</tt>, respectively).
-Curvilinear mesh detector (<tt>'''dn'''</tt>):<span id="det_dn"></span>
+Detector evenly-spaced curvilinear mesh (<tt>'''dn'''</tt>):<span id="det_dn1"></span>
 {|
 | <tt>''TYPE''</tt>
-| : Type of curvilinear mesh - 1 = cylindrical (dimensions ''r'', ''&theta;'', ''z''), 2 = spherical (dimensions ''r'', ''&theta;'', ''&phi;'')
+| : type of curvilinear mesh - 1 = cylindrical (dimensions ''r'', ''&theta;'', ''z''), 2 = spherical (dimensions ''r'', ''&theta;'', ''&phi;'')
 |-
 | <tt>''MIN<sub>n</sub>''</tt>
-| : Minimum value of coordinate ''n'' for the mesh division.
+| : minimum value of ''n''-coordinate for the mesh division [in cm (''r'', ''z''), in degrees (''&theta;'', ''&phi;'')].
 |-
 | <tt>''MAX<sub>n</sub>''</tt>
-| : Maximum value of coordinate ''n'' for the mesh division.
+| : maximum value of ''n''-coordinate for the mesh division [in cm (''r'', ''z''), in degrees (''&theta;'', ''&phi;'')].
 |-
 | <tt>''N<sub>n</sub>''</tt>
-| : Number of bins in the ''n'' coordinate direction (the division will be equal ''r'', not equal volume).
+| : number of bins in the ''n''-coordinate direction (the radial division will be equal ''r'', not equal volume).
 |}
 <u>Notes:</u>
 *All parameters must be provided, even for one- or two-dimensional curvilinear meshes.
-*The results are not divided by cell volume (difference to MCNP mesh tally).
+*By default, the curvilinear mesh detectors use the global (universe 0) coordinate system for scoring.
-*By default, the curvilinear mesh detectors use the global (universe 0) coordinate system for scoring. If the <tt>''TYPE''</tt> parameter is given as a negative value (e.g. -1) the lowest level coordinates are used instead.
+**If the <tt>''TYPE''</tt> parameter is given as a negative value (e.g. -1) the lowest level coordinates are used instead.
+Detector unevenly-spaced mesh (<tt>'''dn'''</tt>):<span id="det_dn2"></span>
+{|
+| <tt>''TYPE''</tt>
+| : type of curvilinear mesh - 3 = unevenly-spaced orthogonal (dimensions ''x'', ''y'', ''z''), 4 = unevenly-spaced cylindrical (dimensions ''r'', ''&theta;'', ''z'')
+|-
+| <tt>''N<sub>n</sub>''</tt>
+| : number of bins in the ''n''-coordinate direction
+|-
+| <tt>''LIM<sub>nm</sub>''</tt>
+| : mesh ''m''-boundary in the ''n''-coordinate direction [in cm (''r'', ''z''), in degrees (''&theta;'', ''&phi;'')].
+|}
+<u>Notes:</u>
+*All parameters must be provided, even for one- or two-dimensional meshes.
+*By default, the unevenly-spaced mesh detectors use the global (universe 0) coordinate system for scoring.
+**If the <tt>''TYPE''</tt> parameter is given as a negative value (e.g. -1) the lowest level coordinates are used instead.
-Hexagonal mesh detector (<tt>'''dh'''</tt>):<span id="det_dh"></span>
+Detector hexagonal mesh (<tt>'''dh'''</tt>):<span id="det_dh"></span>
 {|
 | <tt>''TYPE''</tt>
-| : Type of hexagonal mesh (2 = flat face perpendicular to x-axis, 3 = flat face perpendicular to y-axis)
+| : type of hexagonal mesh (2 = flat face perpendicular to x-axis, 3 = flat face perpendicular to y-axis)
 |-
 | <tt>''X<sub>0</sub>''</tt>, <tt>''Y<sub>0</sub>''</tt>
-| : coordinates of mesh center
+| : coordinates of mesh center [in cm]
 |-
 | <tt>''PITCH''</tt>
-| : mesh pitch
+| : mesh pitch [in cm]
 |-
-| <tt>''N<sub>1</sub>''</tt>, <tt>''N<sub>1</sub>''</tt>
+| <tt>''N<sub>1</sub>''</tt>, <tt>''N<sub>2</sub>''</tt>
 | : mesh size
 |-
 | <tt>''Z<sub>MIN</sub>''</tt>
-| : minimum z-coordinate of the detector mesh
+| : minimum z-coordinate of the detector mesh [in cm]
 |-
 | <tt>''Z<sub>MAX</sub>''</tt>
-| : maximum z-coordinate of the detector mesh
+| : maximum z-coordinate of the detector mesh [in cm]
 |-
 | <tt>''N<sub>Z</sub>''</tt>
@@ Line 454: / Line 901: @@
-Unstructured mesh detector (<tt>'''dumsh'''</tt>):<span id="det_dumsh"></span>
+Detector unstructured mesh (<tt>'''dumsh'''</tt>):<span id="det_dumsh"></span>
 {|
@@ Line 469: / Line 916: @@
 <u>Notes:</u>
 *The polyhedral cells in [[Unstructured mesh-based geometry type|unstructured mesh based geometries]] are indexed.
-*This detector option allows collecting results from the cells into an arbitrary number of bins. One or multiple cells can be mapped into a single bin.
+*This detector option allows collecting results from the cells into an arbitrary number of bins.
+*One or multiple cells can be mapped into a single bin.
@@ Line 481: / Line 929: @@
 <u>Notes:</u>
 *The results are divided into multiple energy bins based on the grid structure.
 *Energy grid structures are defined using the [[#ene (energy grid definition)|ene card]].
+**[[Pre-defined energy group structures]] can not be directly used in detectors, they have to be redefined using for example the type "<tt>4</tt>" of [[#ene|ene card]].
+*The energy boundaries of photon photon pulse-height and photon heat analog detectors are solely defined by the associated energy grid and not limited by the unionized energy grid defining the model.
+**That means that analog detectors might collect scores below the physics model minimum energy bound, without a cut-off, if the energy grid sets it.
@@ Line 497: / Line 948: @@
-Surface current / flux detector (<tt>'''ds'''</tt>):<span id="det_ds"></span>
+Detector current / flux surface (<tt>'''ds'''</tt>):<span id="det_ds"></span>
 {|
@@ Line 509: / Line 960: @@
 <u>Notes:</u>
 *With this option the detector calculates the particle flux over or current through a given surface.
-*The surface flux mode is invoked by setting the direction parameter to -2, otherwise this parameter defines the current direction with respect to surface normal.
+*Flux mode:
-*Responses are not allowed with current detectors.
+**The surface flux mode is invoked by setting the direction parameter to "<tt>-2</tt>", otherwise this parameter defines the current direction with respect to surface normal.
-*The surface is treated separate from the geometry, and its position is always relative to the origin of the root universe. This is the case even if the surface is part of the geometry in another universe.
+*Current mode:
+**Responses are not allowed with current detectors, and with flux detectors, the material name at the collision point has to be specified (<tt>"void"</tt> is not allowed).
+*The use of single-bin mesh and cell detectors is allowed to further define the surface and integration domain of the detector, from version 2.1.32 on.
+*The surface is treated separate from the geometry, and its position is always relative to the origin of the root universe.
+**This is the case even if the surface is part of the geometry in another universe.
 *The results are integrated over the surface area (other detectors integrate over volume).
@@ Line 518: / Line 973: @@
 {|
-| <tt>''COS<sub>Y</sub>''</tt>
+| <tt>''COS<sub>X</sub>''</tt>
 | : component of the direction vector parallel to x-axis
 |-
@@ Line 532: / Line 987: @@
-Super-imposed track-length detector (<tt>'''dtl'''</tt>):<span id="det_dtl"></span>
+Detector super-imposed track-length (<tt>'''dtl'''</tt>):<span id="det_dtl"></span>
 {|
@@ Line 541: / Line 996: @@
 <u>Notes:</u>
 *This option can be used to apply the track-length estimator for calculating reaction rates inside regions defined by a single surface (sphere, cylinder, cuboid, etc.)
+*The surface is treated separate from the geometry, and its position is always relative to the origin of the root universe.
+**This is the case even if the surface is part of the geometry in another universe.
 *The purpose of the track-length detector is to provide better statistics for special applications (activation wire measurements, etc.).
-*The surface is treated separate from the geometry, and its position is always relative to the origin of the root universe. This is the case even if the surface is part of the geometry in another universe.
+*For more information see the detailed description on [[delta- and surface-tracking]] and [[Result estimators#Implicit estimators|result estimators]].
@@ Line 552: / Line 1,009: @@
 |-
 | <tt>''FRAC''</tt>
-| : fraction of recorded scores and ascii/binary option (positive value = ascii, negative value = binary)
+| : fraction of recorded scores and ASCII/binary option (positive value = ASCII, negative value = binary)
 |}
 <u>Notes:</u>
 *This option can be used to write the scored points in a file.
-*When used with the surface current detector this option can provide surface source distributions for other calculations.
 *The fraction parameters gives the probability that the score is written in the file and it can be used to reduce the file size in long simulations.
-*Source files can be read using the <tt>'''sf'''</tt> entry of [[#src_sf|source cards]].
+*When used with the surface current detector this option can provide surface source distributions for other calculations.
+*Source files can be read using the <tt>'''sf'''</tt> entry of the [[#src_sf|src card]].
-Special types (<tt>'''dt'''</tt>):<span id="det_dt"></span>
+Detector special types (<tt>'''dt'''</tt>):<span id="det_dt"></span>
 {|
@@ Line 572: / Line 1,029: @@
 |}
-The types are:
+The possible special types are:
-{|
+::{| class="wikitable" style="text-align: left;"
+! Type
+! Description
+! Notes
+|-
 | -1
-| = cumulative spectrum
+| cumulative spectrum
+| use with energy binning ('''de''')
 |-
 | -2
-| = division by energy width
+| division by energy width
+| use with energy binning ('''de''')
 |-
 | -3
-| = division by lethargy width
+| division by lethargy width
+| use with energy binning ('''de''')
 |-
 | -4
-| = sum over cell or material bins
+| sum over cell or material bins
+| use with cell and/or material binning ('''dc''', '''dm''')
+|-
+| -5
+| importance weighting
+| -
+|-
+| -6
+| sum over number of scores
+| -
 |-
 | 2
-| = multiply result with another detector defined by <tt>''PARAM''</tt>
+| multiply result with another detector defined by <tt>''PARAM''</tt>
+| bin-compatibility
 |-
 | 3
-| = divide result with another detector defined by <tt>''PARAM''</tt>
+| divide result with another detector defined by <tt>''PARAM''</tt>
+| bin-compatibility
+|-
+| 4
+| multiply response function by (local) temperature
+| -
+|-
 |}
 <u>Notes:</u>
-*Types -1, -2 and -3 are used with energy binning.
+*Type "<tt>3</tt> can be used to calculate flux-weighted averages (microscopic and macroscopic cross sections, etc.).
-*Type -4 can be used to calculate sum over multiple cell or material bins defined using the <tt>'''dc'''</tt> and <tt>'''dm'''</tt> options. By default separate bins are used for each entry.
-*Type 3 can be used to calculate flux-weighted averages (microscopic and macroscopic cross sections, etc.).
-*When the results are multiplied or divided by another detector, the number of bins must be compatible (single value or matching number of bins).
-History collection option (<tt>'''dhis'''</tt>):<span id="det_dhis"></span>
+Detector history collection flag (<tt>'''dhis'''</tt>):<span id="det_dhis"></span>
 {|
 | <tt>''OPT''</tt>
-| : option to collect histories (0 = no, 1 = yes)
+| : option to switch on (1/yes) or off (0/no) the collection of histories, batch-wise results
 |}
 <u>Notes:</u>
-*When this option is set, the batch-wise results are kept and printed in the [[history output file]].
+*When this option is set, the batch-wise results are printed in the history output file, <tt>[input]_stats.m</tt>.
+*The statistical tests are described in a related report<ref name="stat_tests">Kaltiaisenaho, T. ''"Statistical tests and the underestimation of variance in Serpent 2."'' VTT-R-00371-14, VTT Technical Research Centre of Finland, [https://serpent.vtt.fi/serpent/download/VTT-R-00371-14.pdf 2014]</ref>.
 *''Note to developers: statistical tests should be documented''
-Detector flagging (<tt>'''dfl'''</tt>):<span id="det_dfl"></span>
+Detector score flagging (<tt>'''dfl'''</tt>):<span id="det_dfl"></span>
 {|
@@ Line 620: / Line 1,099: @@
 | <tt>''OPT''</tt>
 | : flagging option (0 = reset if scored, 1 = set if scored, -2/2 score if set -3/3 score if not set)
+|}
+The possible flagging options are:
+::{| class="wikitable" style="text-align: left;"
+! Flag
+! Description
+! Notes
+|-
+| <tt>0</tt>
+| reset if scored
+| -
+|-
+| <tt>1</tt>
+| set if scored
+| -
+|-
+| <tt>-2/2</tt>
+| score if set
+| 2 (apply OR-type logic), -2 (apply AND-type logic)
+|-
+| <tt>-3/3</tt>
+| score if not set
+| 3 (apply OR-type logic), -3 (apply AND-type logic)
+|-
 |}
 <u>Notes:</u>
 *Detector flagging allows limiting detector scores to histories which have already contributed to another score.
-*The first two options reset or set the flag if the detector is scored, respectively. The remaining options test if the flag is set and score the detector accordingly. Positive values apply OR-type logic (detector is scored if any of the associated flags is set/unset) and negative values AND-type logic (detector is scored if all the associated flags are set/unset).
+*Scoring logic:
+** OR-type logic: detector is scored if any of the associated flags is set/unset
+** AND-type logic:  detector is scored if all the associated flags are set/unset
-Activation detector (<tt>'''da'''</tt>):<span id="det_da"></span>
+Detector activation (<tt>'''da'''</tt>):<span id="det_da"></span>
 {|
@@ Line 634: / Line 1,140: @@
 |-
 | <tt>''FLX''</tt>
-| : flux applied to activation
+| : flux applied to activation [in 1/cm<sup>2</sup>s]
 |}
 <u>Notes:</u>
-*Activation detector allows performing activation calculation for materials that are not part of the geometry. The flux spectrum applied to neutron irradiation is taken from the detector scores. The absolute flux level can be set using the <tt>''FLX''</tt> parameter. If this parameter is set to -1, also the flux magnitude is taken from the detector scores.
+*Activation detector allows performing activation calculation for materials that are not part of the geometry.
-*Requires neutron transport simulation and burnup mode. The material provided with the entry must be burnable, and cannot part of the actual geometry. Volume of the material must be defined using the <tt>'''dv'''</tt> parameter.
+*Flux applied to activation:
+**The flux spectrum applied to neutron irradiation is taken from the detector scores.
+**The absolute flux level can be set using the <tt>''FLX''</tt> parameter.
+***There is a special entry for the <tt>''FLX''</tt> parameter:
+**** "<tt>-1</tt>": in this case, the flux magnitude is also taken from the detector scores.
+*Requires neutron transport simulation and burnup mode.
+*The detector associated material must be burnable, and cannot part of the actual geometry.
+*The volume of the material, aka detector, must be defined using the <tt>'''dv'''</tt> parameter.
 *Since the activated material is not part of the physical geometry, this option should be applied only to small samples and other activation calculations in which the isotopic changes do not significantly affect the neutronics.
-Functional Expansion Tally detector (<tt>'''dfet'''</tt>):<span id="det_dfet"></span>
+Detector Functional Expansion Tally, FET (<tt>'''dfet'''</tt>):<span id="det_dfet"></span>
 {|
@@ Line 652: / Line 1,166: @@
   |}
-{| class="wikitable" style="text-align: left;"
+::{| class="wikitable" style="text-align: left;"
   ! Geometry
   ! <tt>PARAMS</tt>
@@ Line 661: / Line 1,175: @@
   |-
   | rowspan="1"|Cartesian
-  | rowspan="1"|<tt>''X<sub>MIN</sub>'' ''X<sub>MAX</sub>'' ''X<sub>ORDER</sub>'' ''Y<sub>MIN</sub>'' ''Y<sub>MAX</sub>'' ''Y<sub>ORDER</sub>'' ''Z<sub>MIN</sub>'' '' Z<sub>MAX</sub>'' ''Z<sub>ORDER</sub>''</tt>
+  | rowspan="1"|<tt>''X<sub>MIN</sub>'' ''X<sub>MAX</sub>'' ''X<sub>ORDER</sub>'' ''Y<sub>MIN</sub>'' ''Y<sub>MAX</sub>'' ''Y<sub>ORDER</sub>'' ''Z<sub>MIN</sub>'' ''Z<sub>MAX</sub>'' ''Z<sub>ORDER</sub>''</tt>
   | <tt>1</tt>
   | Legendre only
   | <math>\psi(\xi)_n = P_i(\xi_x) P_j(\xi_y) P_k(\xi_z) </math>
   | <math>n = k + J * \left( i * I + j\right)</math>
+ |-
+ | rowspan="1"|Cylindrical
+ | rowspan="1"|<tt> ''R<sub>MAX</sub>'' ''R<sub>ORDER</sub>'' ''H<sub>MIN</sub>'' ''H<sub>MAX</sub>'' ''H<sub>ORDER</sub>'' ''H<sub>ORIENTATION</sub>''</tt>
+ | <tt>2</tt>
+ | ..
+ | ..
+ | ..
   |}
 <u>Notes:</u>
-*<tt>-1</tt> can be supplied as an <tt>''ORDER''</tt> <tt>PARAM</tt> to use the built-in default values
+*"<tt>-1</tt>" can be supplied as an <tt>''ORDER''</tt> <tt>PARAM</tt> to use the built-in default values
 *It is not recommended to configure a single FET detector to span multiple different material regions—use individual detectors for each region instead
 *Specifics of this implementation:
@@ Line 678: / Line 1,199: @@
 ***The generated FET coefficients <math>a_n</math> already have all contributions from the orthonormalization constant pre-included, i.e. <math>c_n</math> from <math>\frac{1}{c_n} = \lVert \psi_n \rVert^2 = \int_\Gamma \psi_n^2 \omega_n </math>
 ***Thus, an FET can be simply reconstructed/sampled from the standard functional series as: <math>F(\xi) = \sum a_n \psi_n(\xi) \omega_n(\xi)</math>
+*From version 2.2.0  and on, FET-based detectors follow the standard normalization set in the calculation. The volume standards for detectors are set as default value for FET-based detectors, meaning detectors are not divided by the physical volume (allowing the use of volume detector '''dv''').
+*In version 2.2.0, the relative error evaluation associated with FET-based detectors has been revisited.
+Detector pulse-height energy broadening (<tt>'''dphb'''</tt>):<span id="det_dphb"></span>
+{|
+| <tt>''PHB''</tt>
+| : user-defined (Gaussian) energy broadening for pulse-height detector function name
+|}
+<u>Notes:</u>
+* User-defined Gaussian energy broadening functions for pulse height detector are defined using the [[#phb|phb card]].
+Detector spatial integration domain and binning based on a generic data mesh (<tt>'''dmesh'''</tt>):<span id="det_dmesh"></span>
+{|
+| <tt>''MESH''</tt>
+| : name of the [[#datamesh|datamesh]] to use for defining the spatial integration domain and binning for the detector scores
+|}
+<u>Notes:</u>
+* Output mesh index will be flattened (one dimensional).
 === div (divisor definition)<span id="div"></span> ===
-  '''div''' ''MAT'' [ '''sep''' ''LVL'' ]
+  '''div''' ''MAT'' [ [[#div_sep|'''sep''']] ''LVL'' ]
-          [ '''subx''' ''N<sub>X</sub>'' ''X<sub>MIN</sub>'' ''X<sub>MAX</sub>'' ]
+          [ [[#div_subx1|'''subx''']] ''N<sub>X</sub>'' ''X<sub>MIN</sub>'' ''X<sub>MAX</sub>'' ]
-          [ '''suby''' ''N<sub>Y</sub>'' ''Y<sub>MIN</sub>'' ''Y<sub>MAX</sub>'' ]
+          [ [[#div_subx2|'''subx''']] ''N<sub>X</sub>'' ''X<sub>1</sub>'' ''X<sub>2</sub>'' ... ''X<sub>N+1</sub>'' ]
-          [ '''subz''' ''N<sub>Z</sub>'' ''Z<sub>MIN</sub>'' ''Z<sub>MAX</sub>'' ]
+         [ [[#div_suby1|'''suby''']] ''N<sub>Y</sub>'' ''Y<sub>MIN</sub>'' ''Y<sub>MAX</sub>'' ]
-          [ '''subr''' ''N<sub>R</sub>'' ''R<sub>MIN</sub>'' ''R<sub>MAX</sub>'' ]
+          [ [[#div_suby2|'''suby''']] ''N<sub>Y</sub>'' ''Y<sub>1</sub>'' ''Y<sub>2</sub>'' ... ''Y<sub>N+1</sub>'' ]
-          [ '''subs''' ''N<sub>S</sub>'' ''S<sub>0</sub>'' ]
+         [ [[#div_subz1|'''subz''']] ''N<sub>Z</sub>'' ''Z<sub>MIN</sub>'' ''Z<sub>MAX</sub>'' ]
-Divides a material into a number of sub-zones. Input values:
+          [ [[#div_subz2|'''subz''']] ''N<sub>Z</sub>'' ''Z<sub>1</sub>'' ''Z<sub>2</sub>'' ... ''Z<sub>N+1</sub>'' ]
+         [ [[#div_subr1|'''subr''']] ''N<sub>R</sub>'' ''R<sub>MIN</sub>'' ''R<sub>MAX</sub>'' ]
+          [ [[#div_subr2|'''subr''']] ''N<sub>R</sub>'' ''R<sub>1</sub>'' ''R<sub>2</sub>'' ... ''R<sub>N+1</sub>'' ]
+         [ [[#div_subs1|'''subs''']] ''N<sub>S</sub>'' ''S<sub>0</sub>'' ]
+         [ [[#div_subs2|'''subs''']] ''N<sub>S</sub>'' ''S<sub>1</sub>'' ''S<sub>2</sub>'' ... ''S<sub>N+1</sub>'' ]
+         [ [[#div_peb|'''peb''']] ''PBED'' ''N<sub>UNI</sub>'' [ ''UNI<sub>1</sub>'' ... ''UNI<sub>N</sub>'' ]  ]
+         [ [[#div_lims|'''lims''']] ''FLAG'' ]
+Divides a material into a number of sub-zones. The first parameter:
 {|
 | <tt>''MAT''</tt>
 | : name of the divided material
-|-
+|}
+The remaining parameters are defined by separate key words followed by the input values.
+<u>Notes:</u>
+*A single div card may include one or several sub-divisions.
+*As general rule:
+** if the number of zones associated with a sub-division is <u>positive</u>, the sub-division is <u>equal volume</u> (see below)
+** if the number of zones associated with a sub-division is <u>negative</u>, the subdivision is <u>user-defined volume</u> (see below)
+*If a material is not divided, all occurrences of it are treated as a single depletion zone (except for depleted materials defined in pin structures: pin-type division).
+*The use of automated instead of manual depletion zone division saves memory, which may become significant in very large burnup calculation problems (see [[#set opti|set opti]]).
+*The volumes of the divided materials must be set manually (see [[#set mvol|set mvol]] option) or automatically, via the Monte Carlo checker-routine (see [[#set mcvol|set mcvol]] option or [[Installing and running Serpent#Running Serpent|''-checkvolumes'']] command line option).
+**For a more detailed description, check [[Defining material volumes|Defining material volumes]]).
+*For more information, see detailed description on [[automated depletion zone division]].
+<u>Sub-division types:</u>
+Sub-division geometry level (<tt>'''sep'''</tt>): <span id="div_sep"></span>
+{|
 | <tt>''LVL''</tt>
-| : geometry level at which the cell-wise division takes place (0 = no division, 1 = last level, 2 = 2nd last level, etc.)
+| : geometry level at which the material-wise division takes place (0 = no division, 1 = last level, 2 = 2nd last level, etc.)
 |-
+|}
+<u>Notes:</u>
+*The sub-division criterion is the geometry level.
+*The level number is counted backwards from the last one, i.e. level "<tt>1</tt>" is the last level.
+*Use examples:
+**to sub-divide the fuel in large LWR core into separate depletion zones on assembly-, instead of pin-basis.
+**to sub-divide HTGR fuel kernels into depletion zones on compact- or pebble-basis.
+Sub-division Cartesian mesh, <u>equal volume</u> (<tt>'''subx'''</tt>, <tt>'''suby'''</tt> and <tt>'''subz'''</tt>):<span id="div_subx1"></span><span id="div_suby1"></span><span id="div_subz1"></span>
+{|
 | <tt>''N<sub>X</sub>''</tt>
-| : number of x-zones
+| : number of x-zones (positive value)
 |-
 | <tt>''X<sub>MIN</sub>''</tt>
-| : minimum x-coordinate (cm)
+| : minimum x-coordinate [in cm]
 |-
 | <tt>''X<sub>MAX</sub>''</tt>
-| : maximum x-coordinate (cm)
+| : maximum x-coordinate [in cm]
 |-
 | <tt>''N<sub>Y</sub>''</tt>
-| : number of y-zones
+| : number of y-zones (positive value)
 |-
 | <tt>''Y<sub>MIN</sub>''</tt>
-| : minimum y-coordinate (cm)
+| : minimum y-coordinate [in cm]
 |-
 | <tt>''Y<sub>MAX</sub>''</tt>
-| : maximum y-coordinate (cm)
+| : maximum y-coordinate [in cm]
 |-
 | <tt>''N<sub>Z</sub>''</tt>
-| : number of z-zones
+| : number of z-zones (positive value)
 |-
 | <tt>''Z<sub>MIN</sub>''</tt>
-| : minimum z-coordinate (cm)
+| : minimum z-coordinate [in cm]
 |-
 | <tt>''Z<sub>MAX</sub>''</tt>
-| : maximum z-coordinate (cm)
+| : maximum z-coordinate [in cm]
 |-
+|}
+<u>Notes:</u>
+* An equal volume sub-division is performed in the given dimension.
+* The value of the parameter <tt>''N<sub>n</sub>''</tt> which defines the number of zones in the given dimension must be positive.
+* For a Cartesian mesh sub-division, a separate entry in x-, y-, z- directions is provided (<tt>'''subx'''</tt>, <tt>'''suby'''</tt> and <tt>'''subz'''</tt>, respectively).
+Sub-division Cartesian mesh, <u>user-defined volume</u> (<tt>'''subx'''</tt>, <tt>'''suby'''</tt> and <tt>'''subz'''</tt>):<span id="div_subx2"></span><span id="div_suby2"></span><span id="div_subz2"></span>
+{|
+| <tt>''N<sub>X</sub>''</tt>
+| : number of x-zones (negative value)
+|-
+| <tt>''X<sub>n</sub>''</tt>
+| : x-coordinate boundaries [in cm]
+|-
+| <tt>''N<sub>Y</sub>''</tt>
+| : number of y-zones (negative value)
+|-
+| <tt>''Y<sub>n</sub>''</tt>
+| : y-coordinate boundaries [in cm]
+|-
+| <tt>''N<sub>Z</sub>''</tt>
+| : number of z-zones (negative value)
+|-
+| <tt>''Z<sub>n</sub>''</tt>
+| : z-coordinate boundaries [in cm]
+|-
+|}
+<u>Notes:</u>
+* An user-defined volume sub-division is performed in the given dimension.
+* The value of the parameter <tt>''N<sub>n</sub>''</tt> which defines the number of zones in the given dimension must be negative.
+* For a Cartesian mesh sub-division, a separate entry in x-, y-, z- directions is provided (<tt>'''subx'''</tt>, <tt>'''suby'''</tt> and <tt>'''subz'''</tt>, respectively).
+Sub-division cylindrical annular mesh, <u>equal volume</u> (<tt>'''subr'''</tt>):<span id="div_subr1"></span>
+{|
 | <tt>''N<sub>R</sub>''</tt>
-| : number of radial zones
+| : number of radial-zones (positive value)
 |-
 | <tt>''R<sub>MIN</sub>''</tt>
-| : minimum radial coordinate (cm)
+| : minimum radial-coordinate [in cm]
 |-
 | <tt>''R<sub>MAX</sub>''</tt>
-| : maximum radial coordinate (cm)
+| : maximum radial-coordinate [in cm]
 |-
+|}
+<u>Notes:</u>
+* An equal volume radial sub-division is performed (annular-type sub-division)
+* The value of the parameter <tt>''N<sub>R</sub>''</tt> which defines the number of zones in the given dimension must be positive.
+Sub-division cylindrical annular mesh, <u>user-defined volume</u> (<tt>'''subr'''</tt>):<span id="div_subr2"></span>
+{|
+| <tt>''N<sub>R</sub>''</tt>
+| : number of radial-zones (negative value)
+|-
+| <tt>''R<sub>n</sub>''</tt>
+| : radial-coordinate boundaries [in cm]
+|-
+|}
+<u>Notes:</u>
+* An user-defined volume radial sub-division is performed (annular-type sub-division)
+* The value of the parameter <tt>''N<sub>R</sub>''</tt> which defines the number of zones in the given dimension must be negative.
+Sub-division cylindrical sector mesh, <u>equal volume</u> (<tt>'''subs'''</tt>):<span id="div_subs1"></span>
+{|
 | <tt>''N<sub>S</sub>''</tt>
-| : number of angular sectors
+| : number of angular-zones (negative value)
 |-
 | <tt>''S<sub>0</sub>''</tt>
-| : zero position of angular division (degrees)
+| : zero position of angular division [in degrees]
+|-
 |}
 <u>Notes:</u>
+* An equal volume angular sub-division is performed (sector-type sub-division)
+* The value of the parameter <tt>''N<sub>S</sub>''</tt> which defines the number of zones in the angular dimension must be positive.
-*The automated divisor feature can be used to sub-divide burnable materials into depletion zones, but the use is not limited to burnup mode.
-*The spatial sub-division is based on either Cartesian or cylindrical mesh.
-*Volumes of the divided materials must be set manually (see detailed description on [[Defining material volumes|the definition of material volumes]]).
-*Using automated instead of manual depletion zone division saves memory, which may become significant in very large burnup calculation problems (see detailed description on [[memory usage#automated depletion zone division|memory usage]]).
-*For more information see detailed description on [[automated depletion zone division]].
-*The usage of <tt>''LVL''</tt> is explained on page [[automated depletion zone division]].
-=== ene (energy grid definition)<span id="ene"></span> ===
+Sub-division cylindrical sector mesh, <u>user-defined volume</u> (<tt>'''subs'''</tt>):<span id="div_subs2"></span>
- '''ene''' ''NAME'' '''1''' ''E<sub>0</sub>'' ''E<sub>1</sub>'' ...
+{|
+| <tt>''N<sub>S</sub>''</tt>
+| : number of angular-zones
+|-
+| <tt>''S<sub>n</sub>''</tt>
+| : angular-sector boundaries [in degrees]
+|-
+|}
- '''ene''' ''NAME'' '''2''' ''N'' ''E<sub>min</sub>'' ''E<sub>max</sub>''
+<u>Notes:</u>
+* An user-defined volume angular sub-division is performed (sector-type sub-division)
+* The value of the parameter <tt>''N<sub>S</sub>''</tt> which defines the number of zones in the angular dimension must be negative.
+* The manually-spaced angular-sector boundaries <tt>''S<sub>n</sub>''</tt> must cover the full/360 degrees angular space.
- '''ene''' ''NAME'' '''3''' ''N'' ''E<sub>min</sub>'' ''E<sub>max</sub>''
- '''ene''' ''NAME'' '''4''' ''GRID''
+Sub-division pebble-bed structure (<tt>'''peb'''</tt>): <span id="div_peb"></span>
+{|
+| <tt>''PBED''</tt>
+| : stochastic particle / pebble-bed structure
+|-
+| <tt>''N<sub>UNI</sub>''</tt>
+| : number of universes to link related to the <tt>''PBED''</tt> structure (special case: 0 = link to all)
+|-
+| <tt>''UNI<sub>N</sub>''</tt>
+|: list of universes to link (non-zero number of universes)
+|-
+|}
+<u>Notes:</u>
+*The pebble bed-based sub-division divides each item in a pebble bed universe as its own item.
+*It features a speed-up on the depletion zone division indexing process with large number of pebble bed structures.
+Sub-division limit enforcement (<tt>'''lims'''</tt>): <span id="div_lims"></span>
+{|
+| <tt>''FLAG''</tt>
+| : flag for mapping regions outside (material) limits to divide material: on (1/yes) or off (0/no). The default option is "<tt>off</tt>"
+|-
+|}
+=== dtrans (detector mesh transformation)<span id="dtrans"></span> ===
+Defines detector mesh transformations. Shortcut for "trans d".
+<u>Notes:</u>
+*The parameters associated with the transformation follow the standard transformation cards syntax without '''trans''' <tt>''TYPE''</tt> identifier.
+*See [[#trans (transformations)|transformations]].
+=== ene (energy grid definition)<span id="ene"></span> ===
+ '''ene''' ''NAME'' ''TYPE'' [ ... ]
 Defines an energy grid structure. Input values:
@@ Line 763: / Line 1,456: @@
 |<tt>''NAME''</tt>
 |: energy grid name
+|-
+|<tt>''TYPE''</tt>
+|: energy grid type
+|-
+|}
+The remaining parameters are type-dependent.
+The available <u>energy grid structure types</u> are:
+::{| class="wikitable" style="text-align: left;"
+! Type
+! Description
+|-
+| [[#ene_1|<tt>1</tt>]]
+| arbitrary defined grid
+|-
+| [[#ene_2|<tt>2</tt>]]
+| equal energy-width bins
+|-
+| [[#ene_3|<tt>3</tt>]]
+| equal lethargy-width bins
+|-
+| [[#ene_4|<tt>4</tt>]]
+| [[pre-defined energy group structures|pre-defined energy group structure]]
+|-
+|}
+The syntax of the available types is as follows:
+ '''ene''' ''NAME'' '''1''' ''E<sub>0</sub>'' ''E<sub>1</sub>'' ... <span id="ene_1"></span>
+{|
 |-
 |<tt>''E<sub>i</sub>''</tt>
-|: bin boundaries (type 1)
+|: bin boundaries [in MeV]
+|-
+|}
+ '''ene''' ''NAME'' '''2''' ''N'' ''E<sub>min</sub>'' ''E<sub>max</sub>'' <span id="ene_2"></span>
+{|
 |-
 |<tt>''N''</tt>
-|: number of equi-width bins (types 2 ad 3)
+|: number of equi-width bins
 |-
 |<tt>''E<sub>min</sub>''</tt>
-|: minimum energy (types 2 and 3)
+|: minimum energy [in MeV]
 |-
 |<tt>''E<sub>max</sub>''</tt>
-|: maximum energy (types 2 and 3)
+|: maximum energy [in MeV]
+|-
+|}
+ '''ene''' ''NAME'' '''3''' ''N'' ''E<sub>min</sub>'' ''E<sub>max</sub>'' <span id="ene_3"></span>
+{|
+|-
+|<tt>''N''</tt>
+|: number of equi-width bins
+|-
+|<tt>''E<sub>min</sub>''</tt>
+|: minimum energy [in MeV]
+|-
+|<tt>''E<sub>max</sub>''</tt>
+|: maximum energy [in MeV]
+|-
+|}
+ '''ene''' ''NAME'' '''4''' ''GRID'' <span id="ene_4"></span>
+{|
 |-
 |<tt>''GRID''</tt>
-|: name of the pre-defined grid (type 4)
+|: name of the [[pre-defined energy group structures|pre-defined energy group structure]]
 |}
 <u>Notes:</u>
+*Energy grid structures are used for several purposes, e.g. with detectors ('''de''' entry in the [[#det_de|det card]]).
-*The first input parameter gives the type (1 = arbitrarily defined, 2 = equal energy-width bins, 3 = equal lethargy-width bins, 4 = pre-defined energy group structure).
-*Energy grid structures are used for several purposes, most commonly with [[#det_de|detectors]].
-*See separate description of [[pre-defined energy group structures]].
 === ftrans (fill transformation)<span id="ftrans"></span> ===
-See [[#trans (transformations)|transformations]].
+Defines fill transformations. Shortcut for "<tt>trans f</tt>".
+<u>Notes:</u>
+*The parameters associated with the transformation follow the standard transformation cards syntax without '''trans''' <tt>''TYPE''</tt> identifier.
+*See [[#trans (transformations)|transformations]].
 === fun (function definition)<span id="fun"></span> ===
@@ Line 801: / Line 1,554: @@
 |-
 |<tt>''TYPE''</tt>
-|: function type (currently only supported type is 1 = point-wise tabular data)
+|: function type
 |}
-The syntax for type 1 is:
+The remaining input values are type-dependent.
-  '''fun''' ''NAME'' '''1''' ''INTT'' ''X<sub>1</sub>'' ''F<sub>1</sub>'' ''X<sub>2</sub>'' ''F<sub>2</sub>'' ...
+<u>Notes:</u>
+* The defined function is linked to detector response using [[ENDF reaction MT's and macroscopic reaction numbers|MT -100 ]] (syntax: dr -100 ''NAME'').
+* The defined function currently is only supported as a flux-based function, aka, flux multiplier.
+The available function types are:
+::{| class="wikitable" style="text-align: left;"
+! Type
+! Description
+|-
+| [[#fun_1|<tt>1</tt>]]
+| point-wise tabular data
+|-
+|}
+The syntax for the available types is as follows:
+  '''fun''' ''NAME'' '''1''' ''INTT'' ''X<sub>1</sub>'' ''F<sub>1</sub>'' ''X<sub>2</sub>'' ''F<sub>2</sub>'' ... <span id="fun_1"></span>
-where:
 {|
 |<tt>''INTT''</tt>
 |: is the interpolation type (1 = histogram, 2 = lin-lin, 3 = lin-log, 4 = log-lin, 5 = log-log)
 |-
-|<tt>''X<sub>1</sub>'' ''F<sub>1</sub>'' ...</tt>
+|<tt>''X<sub>i</sub>'', ''F<sub>i</sub>''</tt>
 |: are the tabulated variable-value pairs
+|}
+=== hisv (history variation matrix definition)<span id="hisv"></span> ===
+ '''hisv''' [ ''BU<sub>1</sub>'' ''NBR<sub>1</sub>'' ''BR<sub>1,1</sub>'' ''BR<sub>1,2</sub>'' ... ''BR<sub>1,NBR<sub>1</sub></sub>'' ]
+      [ ''BU<sub>2</sub>'' ''NBR<sub>2</sub>'' ''BR<sub>2,1</sub>'' ''BR<sub>2,2</sub>'' ... ''BR<sub>2,NBR<sub>2</sub></sub>'' ]
+       ...
+Defines the history variation matrix for the automated burnup sequence. Input values:
+{|
+| <tt>''BU<sub>n</sub>''</tt>
+| : burnup steps at which the branches are invoked (positive value = burnup [in MWd/kg], negative value = time [in d])
+|-
+| <tt>''NBR<sub>n</sub>''</tt>
+| : number branches in the ''n''-th burnup step
+|-
+| <tt>''BR<sub>n,i</sub>''</tt>
+| : name of the ''i''-th branch in the ''n''-th burnup step
 |}
 <u>Notes:</u>
-* The defined function is linked to detector response using [[ENDF reaction MT's and macroscopic reaction numbers|response number]] -100 (syntax: dr -100 ''NAME'').
+*The automated burnup sequence defined by the hisv card follows the same principle as the [[#coef|coef]] input card.
+*The hisv card performs multiple depletions within a single depletion calculation following the historical variation sequence.
+**It performs a restart at each of the listed burnup points, where it applies the variations defined in the listed branches for the given burnup point.
+*The hisv card is used together with the [[#branch|branch]] card.
 === ifc (interface file)<span id="ifc"></span> ===
-  '''ifc''' ''FILE''
+  '''ifc''' ''FILE'' [ [[#ifc_setinmat|'''setinmat''']] ''N<sub>MAT</sub>'' ''MAT<sub>1</sub>'' ''MAT<sub>2</sub>'' ... ''MAT<sub>N<sub>MAT</sub></sub>'' ]
+          [ [[#ifc_setoutmat|'''setoutmat''']] ''N<sub>MAT</sub>'' ''MAT<sub>1</sub>'' ''MAT<sub>2</sub>'' ... ''MAT<sub>N<sub>MAT</sub></sub>'' ]
-Links a [[Multi-physics interface|multi-physics interface]] file to be used with the current input. Input values:
+Links a [[Multi-physics interface|multi-physics interface]] file to be used with the current input. The first parameter:
 {|
 |<tt>''FILE''</tt>
 |: path to the multi-physics interface file
+|}
+The remaining parameters are defined by separate key words followed by the input values, being optional.
+<u>Notes:</u>
+*See also [[Coupled multi-physics calculations]].
+<u>Optional entries:</u>
+Interface input materials  (<tt>'''setinmat'''</tt>): <span id="mix_setinmat"></span>
+{|
+| <tt>''N<sub>MAT</sub>''</tt>
+| : number of input materials to link to the interface
+|-
+| <tt>''MAT<sub>n</sub>''</tt>
+| : name of the ''n''-th input material linked to the interface
+|}
+<u>Notes:</u>
+*It adds the possibility to link multiple input materials to the same interface, i.e. the same interface gives temperatures and densities (density factors) for multiple materials.
+*If multiple input materials are linked to the interface using the option, the densities in the interface file must be given as density factors, i.e. relative to the material card density (values between 0 and 1).
+*If the interface is not updated, the entry is not eligible.
+*If the regular mesh-based interface is used and power is tallied in pin-type objects, the entry is not eligible.
+*The option '''<tt>setinmat</tt>''' is referred as '''<tt>setmat</tt>''' up to version 2.1.31.
+Interface output materials  (<tt>'''setoutmat'''</tt>): <span id="mix_setoutmat"></span>
+{|
+| <tt>''N<sub>MAT</sub>''</tt>
+| : number of output materials to link to the interface
+|-
+| <tt>''MAT<sub>n</sub>''</tt>
+| : name of the ''n''-th output material linked to the interface
 |}
 <u>Notes:</u>
-* See also [[Coupled multi-physics calculations]].
+*It adds the possibility to link multiple output materials to the same interface, i.e. the same interface gives temperatures and densities (density factors) for multiple materials.
+*If multiple input materials are linked to the interface using the option, the densities in the interface file must be given as density factors, i.e. relative to the material card density (values between 0 and 1).
+* If the interface is not updated, the entry is not eligible.
+*If the regular mesh-based interface is used and if power is not tallied on the same mesh, the entry is not eligible.
 === include (read another input file)<span id="include"></span> ===
@@ Line 847: / Line 1,676: @@
 *The include card can be used to simplify the structure of complicated inputs.
-*The input parser starts reading and processing the new file from the point where the input card is placed. Processing of the original file continues after the new file is completed.
+*The input parser starts reading and processing the new file from the point where the input card is placed.
-*The included file must contain complete input cards and and options, it cannot be used to read the values of another card.
+**Processing of the original file continues after the new file is completed.
+*The included file must contain complete input cards and options, it cannot be used to read the values of another card.
+*Nested included file paths must refer to the original base input file or current working directory.
 === lat (regular lattice definition)<span id="lat"></span> ===
-See also Section 3.6 of [http://montecarlo.vtt.fi/download/Serpent_manual.pdf Serpent 1 User Manual].
+  '''lat''' ''UNI'' ''TYPE'' [ ... ]
+Defines a regular lattice universe. Input values:
-<u>Notes:</u>
-*With 2D lattices the numbering of lattice positions is such that the bottommost row is given first from left to right and the topmost row is given last from left to right.
-  '''lat''' ''UNI TYPE X<sub>0</sub> Y<sub>0</sub> N<sub>X</sub> N<sub>Y</sub> PITCH'' ''UNI<sub>1</sub> UNI<sub>2</sub> ...''
-Defines a finite two-dimensional lattice in xy-plane with square or X- or Y-type hexagonal elements. The lattice is infinite in z-direction. Input values:
 {|
@@ Line 868: / Line 1,693: @@
 | : lattice type
 |-
+|}
+The remaining input values are case/type-dependent.
+<u>Notes:</u>
+* For more information, see also Section 3.6 of [http://montecarlo.vtt.fi/download/Serpent_manual.pdf Serpent 1 User Manual].
+The available <u>lattice definitions and types</u> (condensed in five cases) are:
+::{| class="wikitable" style="text-align: left;
+! Case
+! xy-plane description
+! z-direction description
+! Types
+|-
+| [[#lattice_I|<tt>I</tt>]]
+| finite 2D lattice with square, hexagonal or triangular elements
+| infinite z-direction
+| 1 = square, 2 = X-type hexagonal, 3 = Y-type hexagonal, 14 = X-type triangular
+|-
+| [[#lattice_II|<tt>II</tt>]]
+| infinite 2D lattice with square or hexagonal elements
+| infinite z-direction
+| 6 = square, 7 = X-type hexagonal, 8 = Y-type hexagonal
+|-
+| [[#lattice_III|<tt>III</tt>]]
+| finite 2D lattice circular cluster array
+| infinite z-direction
+| 4 = circular cluster array
+|-
+| [[#lattice_IV|<tt>IV</tt>]]
+| infinite xy-plane
+| finite 1D lattice with vertical stack
+| 9 = vertical stack
+|-
+| [[#lattice_V|<tt>V</tt>]]
+| finite 3D lattice with square or hexagonal elements
+| finite 3D lattice
+| 11 = cuboid, 12 = X-type hexagonal prism, 13 = Y-type hexagonal prism
+|-
+|}
+The syntax of the available cases is as follows:
+<u>Case I</u>:<span id="lattice_I"></span>
+finite 2D lattice in xy-plane with square, X- or Y-type hexagonal, or X-type triangular elements, and infinite in z-direction.
+ '''lat''' ''UNI TYPE X<sub>0</sub> Y<sub>0</sub> N<sub>X</sub> N<sub>Y</sub> PITCH'' ''UNI<sub>1</sub> UNI<sub>2</sub> ...''
+{|
 | <tt>''X<sub>0</sub>''</tt>
-| : x-coordinate of the lattice origin
+| : x-coordinate of the lattice origin (origin is in the center of the lattice) [in cm].
 |-
 | <tt>''Y<sub>0</sub>''</tt>
-| : y-coordinate of the lattice origin
+| : y-coordinate of the lattice origin (origin is in the center of the lattice) [in cm].
 |-
 | <tt>''N<sub>X</sub>''</tt>
@@ Line 881: / Line 1,755: @@
 |-
 | <tt>''PITCH''</tt>
-| : lattice pitch
+| : lattice pitch [in cm]
 |-
 | <tt>''UNI<sub>n</sub>''</tt>
@@ Line 887: / Line 1,761: @@
 |}
-Possible lattice types are:
+Possible lattice definitions are:
-{| class="wikitable" style="text-align: left;"
+::{| class="wikitable" style="text-align: left;"
 ! Type
 ! Description
@@ Line 900: / Line 1,774: @@
 | 3
 | Y-type hexagonal lattice
+|-
+| 14
+| X-type triangular lattice
 |}
+[[File:Rect lattice index.png|frame|Lattice type 1 indexing example for N<sub>X</sub> = N<sub>Y</sub> = 3.]]
+[[File:Hex lattice x index.png|frame|Lattice type 2 indexing example for N<sub>X</sub> = N<sub>Y</sub> = 3.]]
+[[File:Hex lattice y index.png|frame|Lattice type 3 indexing example for N<sub>X</sub> = N<sub>Y</sub> = 3.]]
 <u>Notes:</u>
-*Number of universes in list of universes must be N<sub>X</sub> times N<sub>Y</sub>.
+*Number of listed universes universes must be ''N<sub>X</sub> &times; N<sub>Y</sub>''.
-*For square lattices the x coordinate increases from left to right and the y coordinate increases from top to bottom, so the first N<sub>X</sub> values in the list of universes create the bottommost (minimum y) row from minimum x to maximum x and the last N<sub>X</sub> values in the list of universes create the topmost (maximum y) values.
+*For square lattices the x-coordinate increases from left to right and the y-coordinate increases from top to bottom, so the first ''N<sub>X</sub>'' values in the list of universes create the bottommost (minimum y) row from minimum x to maximum x and the last ''N<sub>X</sub>'' values in the list of universes create the topmost (maximum y) values. Example of the indexing is provided in the attached figure.
-*The line breaks usually given in the list of universes are just for visual help of the user.
+*The line breaks usually present in the list of universes are only used to help visualizing the universe order for the user. Serpent ignores them when processing the list of universes.
-*The input of X and Y type hexagonal lattices is similar to each other, only the directions of the x and y axis change. The axis directions are easily checked by using the [[#plot (geometry plot definition)|geometry plotter]].
+*The input of X- and Y-type hexagonal lattices is similar to each other, only the directions of the x- and y-axis change. The axis directions can be checked by using the [[#plot (geometry plot definition)|geometry plotter]]. Examples of the indexing are provided in the attached figures.
- '''lat''' ''UNI TYPE X<sub>0</sub> Y<sub>0</sub> PITCH UNI<sub>1</sub>''
-Defines an infinite two-dimensional lattice in xy-plane with infinitely repeating square or X- or Y-type hexagonal element. The lattice is infinite in z-direction.
+<u>Case II</u>:<span id="lattice_II"></span>
+infinite 2D lattice in xy-plane with infinitely repeating square or X- or Y-type hexagonal element, and infinite in z-direction.
+ '''lat''' ''UNI TYPE X<sub>0</sub> Y<sub>0</sub> PITCH UNI<sub>1</sub>''
 {|
-| <tt>''UNI''</tt>
-| : universe name of the lattice
-|-
-| <tt>''TYPE''</tt>
-| : lattice type
-|-
 | <tt>''X<sub>0</sub>''</tt>
-| : x-coordinate of the lattice origin
+| : x-coordinate of the lattice origin [in cm]
 |-
 | <tt>''Y<sub>0</sub>''</tt>
-| : y-coordinate of the lattice origin
+| : y-coordinate of the lattice origin [in cm]
 |-
 | <tt>''PITCH''</tt>
-| : lattice pitch
+| : lattice pitch [in cm]
 |-
 | <tt>''UNI<sub>1</sub>''</tt>
@@ Line 933: / Line 1,810: @@
 Possible lattice types are:
-{| class="wikitable" style="text-align: left;"
+::{| class="wikitable" style="text-align: left;"
 ! Type
 ! Description
@@ Line 948: / Line 1,825: @@
 <u>Notes:</u>
-*The order of X- and Y-type hexagonal lattice type numbers is reversed when comparing with finite hexagonal lattices.
+*The order of X- and Y-type hexagonal lattice type numbers is reversed when compared with finite hexagonal lattices.
+<u>Case III</u>:<span id="lattice_III"></span>
+finite 2Dl circular cluster array lattice in xy-plane and infinite in z-direction.
   '''lat''' ''UNI TYPE X<sub>0</sub> Y<sub>0</sub> N<sub>R</sub>'' ''N<sub>S,1</sub> RADIUS<sub>1</sub> THETA<sub>1</sub> UNI<sub>1,1</sub> UNI<sub>2,1</sub> ... N<sub>S,2</sub> RADIUS<sub>2</sub> THETA<sub>2</sub> UNI<sub>1,2</sub> UNI<sub>2,2</sub> ... ...''
-Defines a finite two-dimensional circular cluster array lattice in xy-plane. The lattice is infinite in z-direction.
 {|
-| <tt>''UNI''</tt>
-| : universe name of the lattice
-|-
-| <tt>''TYPE''</tt>
-| : lattice type
-|-
 | <tt>''X<sub>0</sub>''</tt>
-| : x-coordinate of the lattice origin
+| : x-coordinate of the lattice origin [in cm]
 |-
 | <tt>''Y<sub>0</sub>''</tt>
-| : y-coordinate of the lattice origin
+| : y-coordinate of the lattice origin [in cm]
 |-
 | <tt>''N<sub>R</sub>''</tt>
@@ Line 971: / Line 1,844: @@
 |-
 | <tt>''N<sub>S,R</sub>''</tt>
-| : number of sectors in R:th ring
+| : number of sectors in ''R''-th ring
 |-
 | <tt>''RADIUS<sub>R</sub>''</tt>
-| : central radius of R:th ring
+| : central radius of ''R''-th ring [in cm]
 |-
 | <tt>''THETA<sub>R</sub>''</tt>
-| : angle of rotation of R:th ring in degrees
+| : angle of rotation of ''R''-th ring [in degrees]
 |-
 | <tt>''UNI<sub>N,R</sub>''</tt>
-| : list of universes filling the sector positions in R:th ring
+| : list of universes filling the sector positions in ''R''-th ring
 |}
-Possible lattice types are:
+Possible lattice type is:
-{| class="wikitable" style="text-align: left;"
+::{| class="wikitable" style="text-align: left;"
 ! Type
 ! Description
@@ Line 995: / Line 1,868: @@
 *The circular cluster array can be used to define fuel assemblies used for example in AGR, CANDU, MAGNOX and RBMK reactors. It can also be used to define fuel rod layout used for example in TRIGA reactors.
- '''lat''' ''UNI TYPE X<sub>0</sub> Y<sub>0</sub> N<sub>L</sub> Z<sub>1</sub> UNI<sub>1</sub> Z<sub>2</sub> UNI<sub>2</sub> ...''
-Defines a finite one-dimensional vertical stack in z-direction. The stack is infinite in xy-plane.
+<u>Case IV</u>:<span id="lattice_IV"></span>
+infinite lattice in xy-plane, and finite 1D vertical stack in z-direction
+ '''lat''' ''UNI TYPE X<sub>0</sub> Y<sub>0</sub> N<sub>L</sub> Z<sub>1</sub> UNI<sub>1</sub> Z<sub>2</sub> UNI<sub>2</sub> ...''
 {|
-| <tt>''UNI''</tt>
-| : universe name of the lattice
-|-
-| <tt>''TYPE''</tt>
-| : lattice type
-|-
 | <tt>''X<sub>0</sub>''</tt>
-| : x-coordinate of the lattice origin
+| : x-coordinate of the lattice origin [in cm]
 |-
 | <tt>''Y<sub>0</sub>''</tt>
-| : y-coordinate of the lattice origin
+| : y-coordinate of the lattice origin [in cm]
 |-
 | <tt>''N<sub>L</sub>''</tt>
@@ Line 1,016: / Line 1,885: @@
 |-
 | <tt>''Z<sub>n</sub>''</tt>
-| : z-coordinate of the n:th lattice element (lower boundary of the axial layer)
+| : z-coordinate of the ''n''-th lattice element (lower boundary of the axial layer) [in cm]
 |-
 | <tt>''UNI<sub>n</sub>''</tt>
-| : universe name filling the n:th lattice position
+| : universe name filling the ''n''-th lattice position
 |}
 Possible lattice types are:
-{| class="wikitable" style="text-align: left;"
+::{| class="wikitable" style="text-align: left;"
 ! Type
 ! Description
@@ Line 1,035: / Line 1,904: @@
 *Space below the lowest z-coordinate is not defined.
 *The top layer fills the entire space above the highest z-coordinate.
-*The number of ''Z<sub>n</sub>-UNI<sub>n</sub>'' pairs must be N<sub>L</sub>.
+*The number of ''Z<sub>n</sub>-UNI<sub>n</sub>'' pairs must be ''N<sub>L</sub>''.
- '''lat''' ''UNI TYPE X<sub>0</sub> Y<sub>0</sub> Z<sub>0</sub> N<sub>X</sub> N<sub>Y</sub> N<sub>Z</sub> PITCH<sub>X</sub> PITCH<sub>Y</sub> PITCH<sub>Z</sub> UNI<sub>1</sub> UNI<sub>2</sub> ...''
-Defines a finite three-dimensional lattice in xyz-space with cuboidal or X- or Y-type hexagonal prism elements.
+<u>Case V</u>:<span id="lattice_V"></span>
+finite 3D lattice in xyz-space with cuboidal or X- or Y-type hexagonal prism elements
+ '''lat''' ''UNI TYPE X<sub>0</sub> Y<sub>0</sub> Z<sub>0</sub> N<sub>X</sub> N<sub>Y</sub> N<sub>Z</sub> PITCH<sub>X</sub> PITCH<sub>Y</sub> PITCH<sub>Z</sub> UNI<sub>1</sub> UNI<sub>2</sub> ...''
 {|
-| <tt>''UNI''</tt>
-| : universe name of the lattice
-|-
-| <tt>''TYPE''</tt>
-| : lattice type
-|-
 | <tt>''X<sub>0</sub>''</tt>
-| : x-coordinate of the lattice origin
+| : x-coordinate of the lattice origin [in cm]
 |-
 | <tt>''Y<sub>0</sub>''</tt>
-| : y-coordinate of the lattice origin
+| : y-coordinate of the lattice origin [in cm]
 |-
 | <tt>''Z<sub>0</sub>''</tt>
-| : z-coordinate of the lattice origin
+| : z-coordinate of the lattice origin [in cm]
 |-
 | <tt>''N<sub>X</sub>''</tt>
@@ Line 1,067: / Line 1,932: @@
 |-
 | <tt>''PITCH<sub>X</sub>''</tt>
-| : lattice pitch in x-direction
+| : lattice pitch in x-direction [in cm]
 |-
 | <tt>''PITCH<sub>Y</sub>''</tt>
-| : lattice pitch in y-direction
+| : lattice pitch in y-direction [in cm]
 |-
 | <tt>''PITCH<sub>Z</sub>''</tt>
-| : lattice pitch in z-direction
+| : lattice pitch in z-direction [in cm]
 |-
 | <tt>''UNI<sub>n</sub>''</tt>
@@ Line 1,080: / Line 1,945: @@
 Possible lattice types are:
-{| class="wikitable" style="text-align: left;"
+::{| class="wikitable" style="text-align: left;"
 ! Type
 ! Description
@@ Line 1,095: / Line 1,960: @@
 <u>Notes:</u>
-*Number of universes in list of universes must be N<sub>X</sub> times N<sub>Y</sub> times N<sub>Z</sub>.
+*Number of universes in list of universes must be ''N<sub>X</sub> &times; N<sub>Y</sub> &times; N<sub>Z</sub>''.
 *For hexagonal prism lattices the x- and y-direction pitches must be equal.
+*The universe indexing is the similar as with lattice types 1-3. The lowermost z-level is given first, and the uppermost z-level is given last.
 === mat (material definition)<span id="mat"></span> ===
@@ Line 1,103: / Line 1,969: @@
   '''mat''' ''NAME DENS'' [ [[#mat_tmp|'''tmp''']] ''TEMP'' ]
+               [ [[#mat_tms|'''tms''']] ''TEMP'' ]
                 [ [[#mat_tft|'''tft''']] ''T<sub>MIN</sub>'' ''T<sub>MAX</sub>'' ]
                 [ [[#mat_rgb|'''rgb''']] ''R G B'' ]
                 [ [[#mat_vol|'''vol''']] ''VOL'' ]
+               [ [[#mat_mass|'''mass''']] ''MASS'' ]
                 [ [[#mat_burn|'''burn''']] ''N<sub>R</sub>'' ]
                 [ [[#mat_fix|'''fix''']] ''ID'' ''TEMP'' ]
+               [ [[#mat_moder|'''moder''']] ''THNAME'' ''ZA'' ]
     ''NUC<sub>1</sub> FRAC<sub>1</sub>''
   [ ''NUC<sub>2</sub> FRAC<sub>2</sub>'' ]
   [    ''...''     ]
-<u>Mandatory information:</u>
+Material definition. The mandatory parameters are:
 {|
 | <tt>''NAME''</tt>
-| : Name of the material
+| : name of the material
 |-
 | <tt>''DENS''</tt>
-| : Density of the material (positive for atomic, negative for mass density) or '''<tt>sum</tt>''' to calculate the density from given nuclide fractions
+| : density of the material (positive value = atomic density [in b<sup>-1</sup>cm<sup>-1</sup>], negative value = mass density [in g/cm<sup>3</sup>])
 |-
-| <tt>''NUC<sub>1</sub>''</tt>
+| <tt>''NUC<sub>n</sub>''</tt>
-| : Identifier of first nuclide in composition, e.g. "92235.03c" or "U-235.03c".
+| : Identifier of ''n''-th nuclide in composition
 |-
-| <tt>''FRAC<sub>1</sub>''</tt>
+| <tt>''FRAC<sub>n</sub>''</tt>
-| : Fraction of first nuclide in composition, positive values are interpreted as atomic fractions/densities, negative values as mass fractions/densities.
+| : fraction of ''n''-th nuclide in composition (positive value = atomic fractions/density, negative values = mass fractions/density)
 |-
 |}
-<u>Optional cards:</u>
+The remaining parameters are defined by separate key words followed by the input values, being optional.
-'''tmp''': <span id="mat_tmp"></span> Material temperature for [[Doppler-broadening preprocessor routine|Doppler-preprocessor]]
+<u>Notes:</u>
+*There is a special entry for the <tt>''DENS''</tt> parameter:
+** "<tt>sum</tt>": to calculate the density from given nuclide fractions
+*The nuclide identifier for nuclides with associated cross-sections corresponds to ZZAAA.ID and, for nuclides without associated cross-sections, e.g., decay nuclides, to ZZAAAI.
+**The identifiers include ''Z'', the atomic number; ''A'', the mass number of the nuclide; ''I'', the isomeric state (0 = ground state, 1 = metastable state); and ''ID'', the library identifier.
+*For more information, see the detailed description on [[Definitions, units and constants#Definitions|Definitions]].
+<u>Optional entries:</u>
+Material temperature for Doppler-broadening pre-processor (<tt>'''tmp'''</tt>): <span id="mat_tmp"></span>
 {|
 | <tt>''TEMP''</tt>
-| : Temperature of the material for [[Doppler-broadening preprocessor routine|Doppler-broadening preprocessor]]
+| : temperature of the material [in K]
 |}
-'''tft''': <span id="mat_tft"></span> Temperature limits for material for [[Coupled multi-physics calculations|coupled multi-physics calculations]]
+<u>Notes:</u>
+*It defines the material temperature for [[Doppler-broadening preprocessor routine|Doppler-preprocessor]].
+Material temperature for on-the-fly temperature treatment (<tt>'''tms'''</tt>): <span id="mat_tms"></span>
+{|
+| <tt>''TEMP''</tt>
+| : temperature of the material [in K]
+|}
+<u>Notes:</u>
+*It defines the material temperature for on-the-fly [[TMS on-the-fly temperature treatment routine‏‎|TMS temperature treatment]].
+Material temperature for coupled multi-physics calculations (<tt>'''tft'''</tt>): <span id="mat_tft"></span>
 {|
 | <tt>''T<sub>MIN</sub>''</tt>
-| : Lower limit for material temperature
+| : lower limit for material temperature [in K]
 |-
 | <tt>''T<sub>MAX</sub>''</tt>
-| : Upper limit for material temperature
+| : upper limit for material temperature [in K]
 |}
-'''rgb''': <span id="mat_rgb"></span> Material color for [[#plot|geometry plots]]
+<u>Notes:</u>
+*It sets the temperature limits for material for [[Coupled multi-physics calculations|coupled multi-physics calculations]].
+*It is used to define the minimum and maximum temperature for the TMS-treatment directly from the interface files (see [[#ifc|ifc]] card).
+*For more information, see the detailed description on the [[multi-physics interface| Multi-physics interface]].
+Material RGB-color (<tt>'''rgb'''</tt>): <span id="mat_rgb"></span>
 {|
 | <tt>''R''</tt>
-| : Value for the red channel of [[#plot|geometry plots]] (between 0 and 255)
+| : value for the red channel (between 0 and 255)
 |-
 | <tt>''G''</tt>
-| : Value for the green channel of geometry plots (between 0 and 255)
+| : value for the green channel (between 0 and 255)
 |-
 | <tt>''B''</tt>
-| : Value for the blue channel of geometry plots (between 0 and 255)
+| : value for the blue channel (between 0 and 255)
 |}
-'''vol''': <span id="mat_vol"></span> Material volume
+<u>Notes:</u>
+*It assigns a dedicated RGB-color to the material for the material representation in [[#plot|geometry plots]].
+*If the entry is not provided, the material color is sampled randomly.
+Material volume (<tt>'''vol'''</tt>): <span id="mat_vol"></span>
 {|
 | <tt>''VOL''</tt>
-| : Volume of the material in cm<sup>3</sup> (3D geometry) or cross-sectional area in cm<sup>2</sup> (2D geometry)
+| : volume of the material [in cm<sup>3</sup>] (3D geometry) or cross-sectional area [in cm<sup>2</sup>] (2D geometry)
 |}
-'''burn''': <span id="mat_burn"></span> Flag material for depletion
+<u>Notes:</u>
+*It defines the material volume.
+*Alternatives ways to provide the material volume includes:
+** [[#set mvol|set mvol]] option, used to define the material volumes manually
+** [[#set mcvol|set mcvol]] option, used to define the material volumes automatically using the Monte Carlo checker routine at runtime.
+** [[Installing and running Serpent#Monte Carlo volume calculation routine|<tt>''-checkvolumes''</tt>]] command line option, used to evaluate the material volumes in an independent run.
+*For more information, see the detailed description on [[defining material volumes|material volumes definition]].
+Material mass (<tt>'''mass'''</tt>): <span id="mat_mass"></span>
+{|
+| <tt>''MASS''</tt>
+| : mass of the material [in g]
+|}
+<u>Notes:</u>
+*The material mass can be provided as an alternative to the material volume.
+Material depletion flag (<tt>'''burn'''</tt>): <span id="mat_burn"></span>
 {|
 | <tt>''N<sub>R</sub>''</tt>
-| : Set to 1 in order to deplete material. The depletion zone division should be done using the [[#div|div]]-card.
+| : option to flag the material as burnable (1/yes) or non-burnable (0/no). The default option is "<tt>non-burnable</tt>"
+|-
 |}
-'''fix''': <span id="mat_fix"></span> Library information for decay nuclides
+<u>Notes:</u>
+*In order to deplete the material and include it in the burnup calculation, the flag must be set to "<tt>1</tt>"
+*The depletion zone division should be done using the [[#div|div]] card. However,
+** if a material is defined within a pin-structure, Serpent, by default if no [[#div|div]] card is associated to the material, sub-divides the material in a pin-type level.
+** in Serpent 1, the "flag" is interpreted as the number of annular regions (not recommended)
+Material library information for nuclides without cross section data (<tt>'''fix'''</tt>): <span id="mat_fix"></span>
 {|
 | <tt>''LIB''</tt>
-| : Library ID (e.g. "09c") for nuclides without cross section data.
+| : library ID (e.g. "09c") for nuclides without cross section data.
 |-
 | <tt>''TEMP''</tt>
-| : Temperature (in Kelvin) for nuclides without cross section data.
+| : temperature for nuclides without cross section data [in K]
+|}
+<u>Notes:</u>
+*It defines the library properties: identifier and temperature for the nuclides without cross section data, e.g. decay nuclides, within the material composition.
+Material associated thermal-scattering data (<tt>'''moder'''</tt>): <span id="mat_moder"></span>
+{|
+| <tt>''THNAME''</tt>
+| : name of the [[#therm_and_thermstoch_.28thermal_scattering.29|thermal scattering data library]]
+|-
+| <tt>''ZA''</tt>
+| : nuclide ZA of the thermal scatterer (e.g. 1001 for H-1).
 |}
 <u>Notes:</u>
-*This description is incomplete for both the descriptions and optional settings.
+*It links the thermal-scattering data library for a given nuclide within the material composition.
-*See [[defining material volumes]] and [[#set mvol|set mvol]] regarding other ways to set the material volumes for for example burnup calculations.
+*The thermal-scattering data library and the associated temperature treatment is defined by the [[#therm_and_thermstoch_.28thermal_scattering.29|therm]] card.
+*A single material can include multiple "<tt>moder</tt>" entries to define thermal-scattering libraries form multiple nuclides, such as H-H20 and D-D20 in semi-heavy water.
 === mesh (mesh plot definition)<span id="mesh"></span> ===
@@ Line 1,204: / Line 2,152: @@
 |-
 | <tt>''XPIX''</tt>
-| : horizontal image size in pixels
+| : horizontal image size [in pixels]
 |-
 | <tt>''YPIX''</tt>
-| : vertical image size in pixels
+| : vertical image size [in pixels]
 |-
 | <tt>''SYM''</tt>
@@ Line 1,213: / Line 2,161: @@
 |-
 | <tt>''MIN<sub>n</sub>'' ''MAX<sub>n</sub>''</tt>
-| : boundaries of the plotted region
+| : boundaries of the plotted region [in cm]
 |-
 | <tt>''CMAP''</tt>
@@ Line 1,231: / Line 2,179: @@
 *Some special detector types, such as pulse-height detectors and analog photon heating detectors cannot be associated with mesh plots.
 *The mesh plot always produces results that are integrated over space. If no boundaries are provided, the integration is carried over the entire geometry.
-*Setting the orientation parameter of a detector mesh plot to 4 produces a plot in cylindrical coordinates. Instead of Cartesian boundaries the entered values are then the radius, angle and axial coordinate.
+*Setting the orientation parameter of a detector mesh plot to 4 produces a plot in cylindrical coordinates. Instead of Cartesian boundaries the entered values are then the radius and axial coordinate.
 *The symmetry option was used in Serpent 1. The parameter must be provided for Serpent 2 as well, even though it is not used. The value can be set to zero.
-*Mesh plot produced by the n:th mesh-card is written in file <tt>[input]_mesh[n].png</tt>.
+*Mesh plot produced by the nth mesh-card is written in file <tt>[input]_mesh[n].png</tt>.
+=== mflow (material flow definition)<span id="mflow"></span> ===
+ '''mflow''' ''NAME''
+    ''NUC<sub>1</sub>'' ''&lambda;<sub>1</sub>''
+  [ ''NUC<sub>2</sub>'' ''&lambda;<sub>2</sub>'' ]
+  [   ''...''   ]
+Defines the material flow. Input values:
+{|
+| <tt>''NAME''</tt>
+| : name of the material flow
+|-
+| <tt>''NUC<sub>n</sub>''</tt>
+| :  identifier of <tt>''n''</tt>-th nuclide in composition
+|-
+| <tt>''&lambda;''<sub>n</sub></tt>
+| : reprocessing constant of <tt>''n''</tt>-th nuclide in composition  [in s<sup>-1</sup>]
+|}
+<u>Notes:</u>
+* The nuclide ID should follow the [[Definitions, units and constants#definitions|ZAI]] or ISO format (e.g., 922350 or U-235).
+* There is a special entry for the nuclide ID:
+** "<tt>all</tt>": in which case all nuclides are included with the same reprocessing fraction ''&lambda;''.
 === mix (mixture definition)<span id="mix"></span> ===
-  '''mix''' ''NAME''
+  '''mix''' ''NAME'' [ [[#mix_rgb|'''rgb''']] ''R G B'' ]
+          [ [[#mix_vol|'''vol''']] ''VOL'' ]
+          [ [[#mix_mass|'''mass''']] ''MASS'' ]
   ''MAT<sub>1</sub>'' ''F<sub>1</sub>''
   ''MAT<sub>2</sub>'' ''F<sub>2</sub>''
   ...
-Defines a mixture of two or several materials. Input values:
+Defines a mixture of two or several materials. Mandatory input values:
 {|
@@ Line 1,248: / Line 2,223: @@
 |-
 | <tt>''F<sub>n</sub>''</tt>
-| : material fraction (positive values for volume, negative values for mass fractions)
+| : material fraction (positive value = volume fraction, negative value = mass fraction)
 |-
 |}
+The remaining parameters are defined by separate key words followed by the input values, being optional.
 <u>Notes:</u>
 *Mixtures can be used to define complicated material definitions consisting of two or more physical materials mixed homogeneously.
-*Serpent decomposes these mixtures into standard materials before running the transport simulation.
+*The mixtures are automatically decomposed into standard materials before running the transport simulation.
-*The decomposed material compositions can be written into file using the [[Installing and running Serpent#Running Serpent|-mix]] command line option.
+**Alternatively, the decomposed material compositions can be written into file using the [[Installing and running Serpent#Running Serpent|<tt>''-mix''</tt>]] command line option.
+*Inherited properties/cards:
+**Nuclide specific thermal scattering data (see '''moder''' entry in the [[#mat_moder|mat]] card) is automatically brought from component materials to the mixture.
+**Other input option such as [[#set_trc|set trc]], [[#set_iter_nuc|set iter nuc]], [[Sensitivity_calculations#Choosing_materials_to_perturb|sens pert matlist]] are not automatically inherited by the mixture from the components.
+**If they are to be applied to the mixture, they should be directly defined using the mixture material name (opposed to component material names) .
+*Burnable mixtures are not supported.
+<u>Optional entries:</u>
+Mixture RGB-color  (<tt>'''rgb'''</tt>): <span id="mix_rgb"></span>
+{|
+| <tt>''R''</tt>
+| : value for the red channel (between 0 and 255)
+|-
+| <tt>''G''</tt>
+| : value for the green channel (between 0 and 255)
+|-
+| <tt>''B''</tt>
+| : value for the blue channel (between 0 and 255)
+|}
+<u>Notes:</u>
+*RGB color coding for material representation in [[#plot|geometry plots]].
+Mixture volume (<tt>'''vol'''</tt>): <span id="mix_vol"></span>
+{|
+| <tt>''VOL''</tt>
+| : volume of the material [in cm<sup>3</sup>] (3D geometry) or cross-sectional area [in cm<sup>2</sup>] (2D geometry)
+|}
+Mixture mass (<tt>'''mass'''</tt>): <span id="mix_mass"></span>
+{|
+| <tt>''MASS''</tt>
+| : mass of the material [in g]
+|}
 === nest (nested universe definition)<span id="nest"></span> ===
-  '''nest''' ''U'' ''TYPE''
+  '''nest''' ''UNI<sub>0</sub>'' ''TYPE''
     [ ''MAT<sub>1</sub>'' ''R<sub>1</sub>'' ]
     [ ''MAT<sub>2</sub>'' ''R<sub>2</sub>'' ]
@@ Line 1,266: / Line 2,283: @@
     [ ''MAT<sub>N</sub>'' ]
-  '''nest''' ''U''
+  '''nest''' ''UNI<sub>0</sub>''
     [ ''MAT<sub>1</sub>'' ''TYPE<sub>1</sub>'' ''PARAM<sub>11</sub> PARAM<sub>12</sub>'' ... ]
     [ ''MAT<sub>2</sub>'' ''TYPE<sub>2</sub>'' ''PARAM<sub>21</sub> PARAM<sub>22</sub>'' ... ]
@@ Line 1,275: / Line 2,292: @@
 {|
-| <tt>''U''</tt>
+| <tt>''UNI<sub>0</sub>''</tt>
 | : universe name
 |-
@@ Line 1,285: / Line 2,302: @@
 |-
 | <tt>''R<sub>1</sub> ... R<sub>N-1</sub>''</tt>
-| : outer radii
+| : outer radii [in cm]
 |-
 | <tt>''TYPE<sub>1</sub> ... TYPE<sub>N-1</sub>''</tt>
 | : nested surface type (different surfaces for each region)
 |-
-| <tt>''PARAM<sub>nm</sub> ... </tt>
+| <tt>''PARAM<sub>nm</sub>'' ... </tt>
 | : surface parameters
 |}
@@ Line 1,296: / Line 2,313: @@
 <u>Notes:</u>
-*The nest card defines an entire universe consisting of nested material regions. The boundaries are defined by surfaces nested inside each other. The outermost region is infinite.
+*The nest card defines an entire universe consisting of nested material regions.
-*The material entries can be replaced by <tt>'''fill''' ''U<sub>0</sub>''</tt>, in which case the region is filled by another universe.
+**The boundaries are defined by surfaces nested inside each other.
-*The first format allows defining nests in which all surfaces are of same type and centred at the origin. Only surfaces that are characterized by a single outer radius are accepted ([[Surface_types#Second-order_quadratic_surfaces|cylinders, spheres]] and some [[Surface_types#Regular_prisms|regular prisms]]). The [[#pin (pin geometry definition)|pin]] and [[#particle (particle geometry definition)|particle]] definitions are short-hand notations of the nest card.
+**The outermost region is infinite.
+*Special <tt>''MAT<sub>i</sub>''</tt> entry: the material entries can be replaced by "<tt>fill ''UNI<sub>i</sub>''</tt>", in which case the region is filled by another universe, <tt>''UNI<sub>i</sub>''</tt>.
+*The first format allows defining nests in which all surfaces are of same type and centred at the origin.
+**Only surfaces that are characterized by a single outer radius are accepted ([[Surface_types#Second-order_quadratic_surfaces|cylinders, spheres]] and some [[Surface_types#Regular_prisms|regular prisms]]).
+**The [[#pin (pin geometry definition)|pin]] and [[#particle (particle geometry definition)|particle]] definitions are short-hand notations of the nest card.
 *The second format allows mixing different surface types. In this case all surface parameters need to be provided after the surface type.
 === particle (particle geometry definition)<span id="particle"></span> ===
-  '''particle''' ''U''
+  '''particle''' ''UNI<sub>0</sub>''
          [ ''MAT<sub>1</sub>'' ''R<sub>1</sub>'' ]
          [ ''MAT<sub>2</sub>'' ''R<sub>2</sub>'' ]
@@ Line 1,311: / Line 2,332: @@
 {|
-| <tt>''U''</tt>
+| <tt>''UNI<sub>0</sub>''</tt>
 | : universe name
 |-
@@ Line 1,318: / Line 2,339: @@
 |-
 | <tt>''R<sub>1</sub> ... R<sub>N-1</sub>''</tt>
-| : outer radii
+| : outer radii [in cm]
 |}
 <u>Notes:</u>
-*The particle card defines an entire universe consisting of nested spherical shells. The boundaries are defined by sphere surfaces. The outermost region is radially infinite.
+*The particle card defines an entire universe consisting of nested spherical shells.
-*The material entries can be replaced by <tt>'''fill''' ''U<sub>0</sub>''</tt>, in which case the region is filled by another universe.
+**The boundaries are defined by sphere surfaces.
+**The outermost region is radially infinite.
+*Special <tt>''MAT<sub>i</sub>''</tt> entry: the material entries can be replaced by "<tt>fill ''UNI<sub>i</sub>''</tt>", in which case the region is filled by another universe, <tt>''UNI<sub>i</sub>''</tt>.
 *Most typically used for defining TRISO fuel particles.
 *The particle card is special case of a [[#nest (nested universe definition)|nested universe type]].
 *See also description of [[#pbed (explicit stochastic geometry)|explicit stochastic geometry type]].
-=== pbed (explicit stochastic (pebble bed) geometry) ===
+=== pbed (explicit stochastic (pebble bed) geometry definition) ===
+ '''pbed''' ''UNI<sub>0</sub>'' ''UNI<sub>bg</sub>'' ''FILE'' [ ''OPT'' ]
+Defines a stochastic particle / pebble-bed geometry. Input values:
+{|
+| <tt>''UNI<sub>0</sub>''</tt>
+| : universe name for the dispersed medium
+|-
+| <tt>''UNI<sub>bg</sub>''</tt>
+| : background universe, i.e. universe filling the space between particles / pebbles
+|-
+| <tt>''FILE''</tt>
+|: input file containing the particle/pebble data
+|-
+| <tt>''OPT''</tt>
+|: additional options
+|}
+The <u>syntax of the file</u> containing the particle/pebble data is:
+::{| class="toccolours" style="text-align: left;"
+| ''X<sub>1</sub>'' ''Y<sub>1</sub>'' ''Z<sub>1</sub>'' ''R<sub>1</sub>'' ''UNI<sub>1</sub>''
+|-
+| ''X<sub>2</sub>'' ''Y<sub>2</sub>'' ''Z<sub>2</sub>'' ''R<sub>2</sub>'' ''UNI<sub>2</sub>''
+|-
+| ...
+|-
+|}
+where:
+{|
+|<tt>''X<sub>n</sub>'', ''Y<sub>n</sub>'', ''Z<sub>n</sub>''</tt>
+|: are the coordinates [in cm]
+|-
+|<tt>''R<sub>n</sub>''</tt>
+|: is the radius [in cm]
+|-
+|<tt>''UNI<sub>n</sub>''</tt>
+|: is the universe
+|}
+The supported <u>additional options</u> are:
+::{| class="wikitable" style="text-align: left;"
+! Option
+! Description
+|-
+| <tt>pow</tt>
+| power distribution
+|-
+|}
+<u>Notes:</u>
+*Creates a universe (<tt>''UNI<sub>0</sub>''</tt>), which is filled with spherical sub-universes for which the coordinates are read from a separate file.
+*The coordinates can be defined manually, or using the [[Installing_and_running_Serpent#Running Serpent|<tt>''-disperse''</tt>]] command line option which launches the particle disperser routine.
+*Can be used for modelling stochastic particle / pebble-bed geometries in multiple levels.
+*If the "<tt>pow</tt>" (power distribution) option is set, the pebble/particle-wise distribution is written in file <tt>[''FILE'']_pow[bu].m</tt>, where "<tt>bu</tt>" is the burnup step, from version 2.2.1 and on (in previous versions, <tt>[''FILE''].out</tt>).
+*See also [[Collection_of_example_input_files#Simple_burnup_examples|HTGR geometry examples]].
+=== phb (pulse-height Gaussian energy broadening definition) <span id="phb"></span>===
+ '''phb''' ''NAME'' ''TYPE'' [ ... ]
+Defines a user-defined (Gaussian) energy broadening function for pulse-height detector ([[#det_dphb|'''dphb''']]). Input values:
+{|
+|<tt>''NAME''</tt>
+|: pulse-height (Gaussian) energy broadening function name
+|-
+|<tt>''TYPE''</tt>
+|: pulse-height function type
+|}
+The remaining input values are type-dependent.
+The <u>pulse-height funtion types</u> are:
+::{| class="wikitable" style="text-align: left;"
+! Type
+! Description
+|-
+| [[#phb_1|<tt>1</tt>]]
+| energy-resolution interpolation
+|-
+| [[#phb_2|<tt>2</tt>]]
+| energy-FWHM interpolation
+|-
+| [[#phb_3|<tt>3</tt>]]
+| energy-resolution fitting
+|-
+| [[#phb_4|<tt>4</tt>]]
+| energy-FWHM fitting
+|-
+|}
+The syntax for the available types is as follows:
+ '''phb''' ''NAME'' '''1''' ''INTT'' ''E<sub>max,1</sub>'' ''R<sub>1</sub>'' ''E<sub>max,2</sub>'' ''R<sub>2</sub>'' ... <span id="phb_1"></span>
+{|
+|<tt>''INTT''</tt>
+|: is the interpolation type (currently only supported type is 2 = lin-lin interpolation data)
+|-
+|<tt>''E<sub>max,i</sub>, R<sub>i</sub>''</tt>
+|: are the maximum energy-resolution tabulated pairs [in MeV (energy)]
+|}
+<u>Notes:</u>
+* Full width at half maximum is calculated as: <math> FWHM(E_{max,i}) =  R(E_{max,i}) E_{max,i} </math>
+* Energies should be given in ascending order.
+ '''phb''' ''NAME'' '''2''' ''INTT'' ''E<sub>max,1</sub>'' ''FWHM<sub>1</sub>'' ''E<sub>max,2</sub>'' ''FWHM<sub>2</sub>'' ... <span id="phb_2"></span>
+{|
+|<tt>''INTT''</tt>
+|: is the interpolation type (currently only supported type is 2 = lin-lin interpolation data)
+|-
+|<tt>''E<sub>max,i</sub>, FWHM<sub>i</sub>''</tt>
+|: are the maximum energy-full width at half maximum pairs [in MeV (energy)]
+|}
+<u>Notes:</u>
+* Energies should be given in ascending order.
+ '''phb''' ''NAME'' '''3''' ''a'' ''b'' <span id="phb_3"></span>
+{|
+|<tt>''a, b''</tt>
+|: are the parameters to define the energy resolution fit:  <math> R = aE^b </math>
+|}
+ '''phb''' ''NAME'' '''4''' ''a'' ''b'' ''c'' <span id="phb_4"></span>
+{|
+|<tt>''a, b, c''</tt>
+|: are the parameters to define the energy full width at half maximum fit: <math> FWHM =  a + b\sqrt{(E + cE^2)} </math>
+|}
 === pin (pin geometry definition)<span id="pin"></span> ===
-  '''pin''' ''U''
+  '''pin''' ''UNI<sub>0</sub>''
     [ ''MAT<sub>1</sub>'' ''R<sub>1</sub>'' ]
     [ ''MAT<sub>2</sub>'' ''R<sub>2</sub>'' ]
@@ Line 1,341: / Line 2,502: @@
 {|
-| <tt>''U''</tt>
+| <tt>''UNI<sub>0</sub>''</tt>
 | : universe name
 |-
@@ Line 1,348: / Line 2,509: @@
 |-
 | <tt>''R<sub>1</sub> ... R<sub>N-1</sub>''</tt>
-| : outer radii
+| : outer radii [in cm]
 |}
 <u>Notes:</u>
-*The pin card defines an entire universe consisting of nested annular material regions. The boundaries are defined by axially infinite cylindrical surfaces. The outermost region is radially infinite.
+*The pin card defines an entire universe consisting of nested annular material regions.
-*The material entries can be replaced by <tt>'''fill''' ''U<sub>0</sub>''</tt>, in which case the region is filled by another universe.
+**The boundaries are defined by axially infinite cylindrical surfaces.
+**The outermost region is radially infinite.
+*Special <tt>''MAT<sub>i</sub>''</tt> entry: the material entries can be replaced by "<tt>fill ''UNI<sub>i</sub>''</tt>", in which case the region is filled by another universe, <tt>''UNI<sub>i</sub>''</tt>.
 *Most typically used for defining fuel pins, but can also be applied to guide tubes, control rods, etc.
 *The pin card is special case of a [[#nest (nested universe definition)|nested universe type]].
@@ Line 1,371: / Line 2,534: @@
 |-
 | <tt>''XPIX''</tt>
-| : horizontal image size in pixels
+| : horizontal image size [in pixels]
 |-
 | <tt>''YPIX''</tt>
-| : vertical image size in pixels
+| : vertical image size [in pixels]
 |-
 | <tt>''POS''</tt>
-| : position of plot plane
+| : position of plot plane [in cm]
 |-
 | <tt>''MIN<sub>1</sub>''</tt>
-| : minimum horizontal coordinate of plotted region
+| : minimum horizontal coordinate of plotted region [in cm]
 |-
 | <tt>''MAX<sub>1</sub>''</tt>
-| : maximum horizontal coordinate of plotted region
+| : maximum horizontal coordinate of plotted region [in cm]
 |-
 | <tt>''MIN<sub>2</sub>''</tt>
-| : minimum vertical coordinate of plotted region
+| : minimum vertical coordinate of plotted region [in cm]
 |-
 | <tt>''MAX<sub>2</sub>''</tt>
-| : maximum vertical coordinate of plotted region
+| : maximum vertical coordinate of plotted region [in cm]
 |-
 | <tt>''F<sub>min</sub>''</tt>
@@ Line 1,398: / Line 2,561: @@
 |-
 | <tt>''E''</tt>
-| : particle energy for importance map plots
+| : particle energy for importance map plots [in MeV]
 |}
 <u>Notes:</u>
-*The type parameter consists of one or two concatenated values ('AB'):
+*The <tt>''TYPE''</tt> parameter consists of one ('A') or two concatenated values ('AB'):
-*#The first value ('A') defines the plot plane (1 = yz, 2 = xz, 3 = xy).
+**The first value ('A') defines the plot plane (yz-plot = 1, "<tt>x</tt>", xz-plot = 2, "<tt>y</tt>", xy-plot = 3, "<tt>z</tt>").
-*#The second value ('B') defines which boundaries are plotted (0 = no boundaries, 1 = cell boundaries, 2 = material boundaries, 3 = both). If the second value in is not provided, material boundaries are plotted.
+**The second value ('B') defines which boundaries are plotted (0 = no boundaries, 1 = cell boundaries, 2 = material boundaries, 3 = both cell and material boundaries).
-*Importance maps read using the [[#wwin (weight window mesh definition)|wwin card]] can be plotted on top of the geometry by setting the second value ('B') of the type parameter to 4 (linear color scheme) or 5 (logarithmic color scheme). The input parameters then also include the minimum and maximum importance and the particle energy. If importance maps are provided for both neutrons and photons, they can be plotted by entering positive and negative energy values, respectively.
+***If the second value ('B') is not provided, default value 2 = material boundaries is used.
-*Each material plotted with different color. The colors are sampled randomly, unless defined using the rgb entry in the [[#mat (material definition)|material card]].
+*The relative dimensions of image size (<tt>''XPIX''</tt>, <tt>''YPIX''</tt>) should match that of the plotted region. Otherwise the image gets distorted.
-*Void is plotted in black and special colors are used to plot geometry errors (red = overlap, green = undefined region).
+*The position parameter <tt>''POS''</tt> defines the location of the plot plane on the axis perpendicular to it (e.g. z-coordinate for xy-type plot).
-*The position parameter defines the location of the plot plane on the axis perpendicular to it (e.g. z-coordinate for xy-type plot).
+*The minimum and maximum coordinates: <tt>''MIN<sub>n</sub>''</tt>, <tt>''MAX<sub>n</sub>''</tt>, define the boundaries of the plotted region (e.g. minimum and maximum x- and y-coordinates for xy-type plot).
-*The minimum and maximum coordinates define the boundaries of the plotted region (e.g. minimum and maximum x- and y-coordinates for xy-type plot). If these coordinates are not provided, the plot is extended to the maximum dimensions of the geometry.
+** If the coordinates are not provided, the plot is extended to the maximum dimensions of the geometry.
-*The relative dimensions of image size in pixels should match that of the plotted region. Otherwise the image gets distorted.
-*Geometry plotter requires compiling the source code with [[Compiling Serpent|GD Graphics libraries]].
+*The second format allows to plot he importance maps read using the [[#wwin (weight window mesh definition)|wwin card]]:
-*[[Installing and running Serpent#Running Serpent|Command line parameter]] '-plot' stops the execution after the geometry plots are produced. Option '-qp' invokes a quick plot mode, which does not check for overlaps. Option '-noplot' skips the geometry plots altogether.
+**They can be plotted on top of the geometry by setting the second value ('B') of the type parameter for:
+*** Cell importances: 4 (linear color scheme) or 5 (logarithmic color scheme)
+*** Source importances: 6 (linear color scheme) or 7 (logarithmic color scheme)
+**The input parameters include the minimum and maximum importance (<tt>''F<sub>min</sub>''</tt>, <tt>''F<sub>max</sub>''</tt>) and the particle energy, <tt>''E''</tt>.
+***If importance maps are provided for both neutrons and photons, they can be plotted by entering positive and negative energy values, respectively.
+***If both, minimum and maximum importance values are set to "-1", Serpent automatically adjusts them based on the weight-window mesh data, from version 2.2.0 and on.
+****If the calculation fails on providing those minimum and maximum values due to the weight-window evaluation, the values are set by default to (1E-200, 1E+200).
+**''Note to developers: particle type should be included as an input parameter in importance map plots.''
+*Material colors:
+**Each material plotted with different color.
+**The colors are sampled randomly, unless defined using the '''rgb''' entry in the material card (see [[#mat (material definition)|mat]]) or mixture card (see [[#mix (mixture definition)|mix]])
+**Special RGB-colors:
+::{|class="wikitable" style="text-align: left;"
+! RGB value
+! Color
+! Description
+|-
+| (0, 0, 0)
+| <span style="color:#000; background:#000">COLOR</span>
+| Outside cell or void-material
+|-
+| (0, 255, 0)
+| <span style="color:#00FF00; background:#00FF00">COLOR</span>
+| No cell found at coordinates
+|-
+| (255, 0, 0)
+| <span style="color:#FF0000; background:#FF0000">COLOR</span>
+| Overlap of multiple cells found at coordinates
+|-
+| (255, 0, 255)
+| <span style="color:#FF00FF; background:#FF00FF">COLOR</span>
+| Undefined material density factor at coordinates
+|}
+*Geometry plotter requires compiling the source code with [[Installing and running Serpent#GD Graphics library|GD Graphics libraries]].
+*Command line options:
+**[[Installing and running Serpent#Running Serpent|<tt>''-plot''</tt>]] stops the execution after the geometry plots are produced
+**[[Installing and running Serpent#Running Serpent|<tt>''-qp''</tt>]] invokes a quick plot mode, which does not check for overlaps
+**[[Installing and running Serpent#Running Serpent|<tt>''-noplot''</tt>]] skips the geometry plots altogether
 *See also [[Visualizing the results#Geometry plotter|detailed description]] on geometry plotter.
-*Geometry plot produced by the n:th plot-card is written in file <tt>[input]_geom[n].png</tt>.
+*The geometry plot produced by the ''n''-th plot-card is written in file <tt>[input]_geom[n].png</tt>.
-*''Note to developers: particle type should be included as an input parameter in importance map plots.''
+=== rep (reprocessor definition)<span id="rep"></span> ===
+ '''rep''' ''NAME''
+    [ [[#rep_rc|'''rc''']] ''SRC'' ''TGT'' ''MFLOW'' ''MODE'' ]
+    [ [[#rep_rm|'''rm''']] ''MAT<sub>1</sub>'' ''MAT<sub>2</sub>'' ]
+    [ [[#rep_ru|'''ru''']] ''UNI<sub>1</sub>'' ''UNI<sub>2</sub>'' ]
+Defines the reprocessing controllers. The first parameter:
+{|
+| <tt>''NAME''</tt>
+| : name of the reprocessor.
+|}
+The remaining parameters are defined by separate key words followed by the input values.
+<u>Notes:</u>
+*The reprocessor name identifies the reprocessing regime in the depletion calculation [[#dep|dep card]]. The syntax corresponds to '''dep pro''' ''NAME''.
+*Multiple reprocessing controllers/regimes can be defined within the same reprocessor definition.
+<u>Reprocessing regime types:</u>
+Reprocessing continuos regime (<tt>'''rc'''</tt>):<span id="rep_rc"></span>
+{|
+| <tt>''SRC''</tt>
+| : name of the source material, from which the flow is moved
+|-
+| <tt>''TGT''</tt>
+| : name of the target material, to which the flow is moved
+|-
+| <tt>''MFLOW''</tt>
+| : name of the material flow
+|-
+| <tt>''MODE''</tt>
+| : continuous reprocessing mode
+|-
+|}
+<u>Notes:</u>
+*The nuclides identifier of those included in both source <tt>''SRC''</tt> and target <tt>''TGT''</tt> materials in reprocessors should follow the same format
+**ZA.ID or ISO.ID (for nuclides with cross sections) or ZAI (for nuclides without associated cross sections, and adding the '''fix''' entry to the [[#mat (material definition)|mat card]]).
+**For more information, see the detailed description on [[Definitions, units and constants#definitions|Nuclide IDs]]).
+*The continuous reprocessing regime works with materials, not universes. Therefore, define the universes associated with those burnable materials as surface-cell type universes.
+*The continuous reprocessing regime can be used to define the material flow between the source and the target materials.
+**The material flow is defined using the [[#mflow|mflow card]].
+**The continuous reprocessing <tt>''MODE''</tt> defines how to incorporate the material flow into the Bateman equations:
+::{|class="wikitable" style="text-align: center;"
+! <tt>''MODE''</tt>
+! Material source
+! Material target
+! Material flow
+|-
+| 0
+| <math>N_{src}(t)=N_{src}(0)</math>
+| <math>N_{tgt}(t)=N_{tgt}(0)+t\lambda N_{src}(0)</math>
+| <math>\dot{N}(t)=\lambda N_{src}(0)</math>
+|-
+| 1
+| <math>N_{src}(t)=N_{src}(0)e^{-\lambda t}</math>
+| <math>N_{tgt}(t) = N_{tgt}(0) + (1-e^{-\lambda t})N_{src}(0)</math>
+| <math>\dot{N}(t)=\lambda N_{src}(t)</math>
+|-
+| 2
+| <math>N_{src}(n+1)=(1-\Delta t_{n}\lambda)N_{src}(n)</math>
+| <math>N_{tgt}(n+1)=N_{tgt}(n)+\Delta t_{n}\lambda N_{src}(n)</math>
+| <math>\dot{N}(n)=\lambda N_{src}(n)</math>
+|}
+:*<tt>''MODE''</tt> 0 : no changes at the source material and adds ''&lambda;N<sub>0</sub>'' from the source material to the target material when solving the Bateman equations (''N<sub>0</sub>'' are initial compositions).
+:*<tt>''MODE''</tt> 1 : subtracts ''&lambda;N'' from the source material and adds it to the target material when solving the Bateman equations.
+:*<tt>''MODE''</tt> 2 : subtracts ''&lambda;N<sub>n</sub>'' from the source material and adds it to the target material when solving the Bateman equations (compositions updated with each burnup step, ''n'').
+Reprocessing material regime (<tt>'''rm'''</tt>):<span id="rep_rm"></span>
+{|
+| <tt>''MAT<sub>1</sub>''</tt>
+| : name of the replaced material
+|-
+| <tt>''MAT<sub>2</sub>''</tt>
+| : name of the replacing material
+|-
+|}
+<u>Notes:</u>
+*The material reprocessing regime replaces one material with another, ''MAT<sub>1</sub>'' by ''MAT<sub>2</sub>''.
+Reprocessing universe regime (<tt>'''ru'''</tt>):<span id="rep_ru"></span>
+{|
+| <tt>''UNI<sub>1</sub>''</tt>
+| : name of the replaced universe
+|-
+| <tt>''UNI<sub>2</sub>''</tt>
+| : name of the replacing universe
+|-
+|}
+<u>Notes:</u>
+*The universe reprocessing regime replaces one universe with another, ''UNI<sub>1</sub>'' by ''UNI<sub>2</sub>''.
-=== sample (Temperature / density data sample definition)<span id="sample"></span> ===
+=== sample (temperature / density data sample definition)<span id="sample"></span> ===
   '''sample'''  ''N<sub>X</sub>'' ''X<sub>MIN</sub>'' ''X<sub>MAX</sub>''  ''N<sub>Y</sub>'' ''Y<sub>MIN</sub>'' ''Y<sub>MAX</sub>''  ''N<sub>Z</sub>'' ''Z<sub>MIN</sub>'' ''Z<sub>MAX</sub>''
@@ Line 1,428: / Line 2,734: @@
 {|
 | <tt>''N<sub>X</sub>''</tt>
-| : Number of values to sample in the x-direction.
+| : number of values to sample in the x-direction.
 |-
 | <tt>''X<sub>MIN</sub>''</tt>
-| : Minimum coordinate to sample from in the x-direction.
+| : minimum coordinate to sample from in the x-direction [in cm]
 |-
 | <tt>''X<sub>MAX</sub>''</tt>
-| : Maximum coordinate to sample from in the x-direction.
+| : maximum coordinate to sample from in the x-direction [in cm]
 |-
 | <tt>''N<sub>Y</sub>''</tt>
-| : Number of values to sample in the y-direction.
+| : number of values to sample in the y-direction.
 |-
 | <tt>''Y<sub>MIN</sub>''</tt>
-| : Minimum coordinate to sample from in the y-direction.
+| : minimum coordinate to sample from in the y-direction [in cm]
 |-
 | <tt>''Y<sub>MAX</sub>''</tt>
-| : Maximum coordinate to sample from in the y-direction.
+| : maximum coordinate to sample from in the y-direction [in cm]
 |-
 | <tt>''N<sub>Z</sub>''</tt>
-| : Number of values to sample in the z-direction.
+| : number of values to sample in the z-direction.
 |-
 | <tt>''Z<sub>MIN</sub>''</tt>
-| : Minimum coordinate to sample from in the z-direction.
+| : minimum coordinate to sample from in the z-direction [in cm]
 |-
 | <tt>''Z<sub>MAX</sub>''</tt>
-| : Maximum coordinate to sample from in the z-direction.
+| : maximum coordinate to sample from in the z-direction [in cm]
 |-
 |}
@@ Line 1,458: / Line 2,764: @@
 <u>Notes:</u>
-*The data from each sample is written in a separate <tt>[input]_sample''N''.m</tt> file.
+*The data from each sample is written in a separate output file:
-*Positive values for the density data correspond to atomic densities, while negative values correspond to mass densities.
+**Default: <tt>[input]_sample[n].m</tt>, where "<tt>n</tt>" is the sample number.
-*Materials with no temperature specified either in their [[Input syntax manual#mat|mat]]-card or through an interface definition will show a temperature of 0.
+**Coupled multi-physics calculation: <tt>[input]_sample[n]_iter[i].m</tt>, where "<tt>i</tt>" is the iteration number.
+**Burnup calculations: <tt>[input]_sample[n]_bstep[bu].m</tt>, where "<tt>bu</tt>" is the burnup step index.
+*** Coupled multi-physics calculation: <tt>[input]_sample[n]_bstep[bu]_iter[i].m</tt>
+**Time-dependent calculations: <tt>[input]_sample[n]_tstep[t].m</tt>, where "<tt>t</tt>" is the time step index
+*** Coupled multi-physics calculation: <tt>[input]_sample[n]_tstep[t]_iter[i].m</tt>
+*Sampling units:
+** Density: positive values = atomic densities [in b<sup>-1</sup> cm<sup>-1</sup>], negative value = mass density [in g/cm<sup>3</sup>].
+** Temperature: [in K]
+*Materials with no temperature specified either in their [[#mat|mat]] card or through an interface [[#ifc|ifc]] card definition will show a temperature of 0 K.
 === sens (sensitivity calculation definition)<span id="sens"></span> ===
@@ Line 1,472: / Line 2,786: @@
 === solid (irregular 3D geometry definition)<span id="solid"></span> ===
-  '''solid 1''' ''UNI'' ''BGUNI''
+  '''solid 1''' ''UNI<sub>0</sub>'' ''BGUNI''
   ''MESH_SPLIT'' ''MESH_DIM'' ''SZ<sub>1</sub>'' ''SZ<sub>2</sub>'' ... ''SZ<sub>MESH_DIM</sub>''
   ''POINTS_FILE''
@@ Line 1,483: / Line 2,797: @@
 {|
-| <tt>''UNI''</tt>
+| <tt>''UNI<sub>0</sub>''</tt>
 | : universe name for the irregular geometry
 |-
@@ Line 1,490: / Line 2,804: @@
 |-
 | <tt>''MESH_SPLIT''</tt>
-| : Splitting criterion for the adaptive search mesh (maximum number of geometry cells in search mesh cell)
+| : splitting criterion for the adaptive search mesh (maximum number of geometry cells in search mesh cell)
 |-
 | <tt>''MESH_DIM''</tt>
@@ Line 1,496: / Line 2,810: @@
 |-
 | <tt>''SZ<sub>i</sub>''</tt>
-| : Size of the search mesh at level <tt>''i''</tt>
+| : size of the search mesh at level <tt>''i''</tt>
 |-
 | <tt>''POINTS_FILE''</tt>
-| : Path to the unstructured mesh points file
+| : path to the unstructured mesh points file
 |-
 | <tt>''FACES_FILE''</tt>
-| : Path to the unstructured mesh faces file
+| : path to the unstructured mesh faces file
 |-
 | <tt>''OWNER_FILE''</tt>
-| : Path to the unstructured mesh owner file
+| : path to the unstructured mesh owner file
 |-
 | <tt>''NEIGHBOUR_FILE''</tt>
-| : Path to the unstructured mesh neighbour file
+| : path to the unstructured mesh neighbour file
 |-
 | <tt>''MATERIALS_FILE''</tt>
-| : Path to the unstructured mesh materials file
+| : path to the unstructured mesh materials file
 |}
+<u>Notes:</u>
+*For more information on the unstructured mesh based geometry see [[Unstructured mesh based input]].
+*For a practical example: [[Simple umsh 8 cubes input]].
-  '''solid 2''' ''UNI'' ''BGUNI''
+  '''solid 2''' ''UNI<sub>0</sub>'' ''BGUNI''
   ''MESH_SPLIT'' ''MESH_DIM'' ''SZ<sub>1</sub>'' ''SZ<sub>2</sub>'' ... ''SZ<sub>MESH_DIM</sub>''
   ''MODE'' ''R0''
@@ Line 1,530: / Line 2,847: @@
 {|
-| <tt>''UNI''</tt>
+| <tt>''UNI<sub>0</sub>''</tt>
 | : universe name for the irregular geometry
 |-
@@ Line 1,537: / Line 2,854: @@
 |-
 | <tt>''MESH_SPLIT''</tt>
-| : Splitting criterion for the adaptive search mesh (maximum number of geometry cells in search mesh cell)
+| : splitting criterion for the adaptive search mesh (maximum number of geometry cells in search mesh cell)
 |-
 | <tt>''MESH_DIM''</tt>
@@ Line 1,546: / Line 2,863: @@
 |-
 | <tt>''MODE''</tt>
-| : Mode for handling the triangulated geometry (1 = "fast", 2 = "safe").
+| : mode for handling the triangulated geometry (1 = "fast", 2 = "safe").
 |-
 | <tt>''R0''</tt>
-| : Radius inside which two points of the STL-geometry are joined into one.
+| : radius inside which two points of the STL-geometry are joined into one.
 |-
 | <tt>''BODY<sub>i</sub>''</tt>
-| : Name of solid body <tt>''i''</tt>
+| : name of solid body <tt>''i''</tt>
 |-
 | <tt>''CELL<sub>i</sub>''</tt>
-| : Name of geometry cell <tt>''i''</tt> linked with body <tt>''i''</tt>
+| : name of geometry cell <tt>''i''</tt> linked with body <tt>''i''</tt>
 |-
 | <tt>''MAT<sub>i</sub>''</tt>
-| : Material filling cell <tt>''i''</tt>
+| : material filling cell <tt>''i''</tt>
 |-
 | <tt>''FILE<sub>i</sub>''</tt>
-| : Path to a file containing an STL solid model, multiple files can be linked to one body
+| : path to a file containing an STL solid model, multiple files can be linked to one body
 |-
 | <tt>''SCALE<sub>i</sub>''</tt>
-| : Scaling factor for the STL model in <tt>''FILE<sub>i</sub>''</tt>
+| : scaling factor for the STL model in <tt>''FILE<sub>i</sub>''</tt>
 |-
 | <tt>''X<sub>i</sub>''</tt>
-| : Shift in x-direction to the STL model in <tt>''FILE<sub>i</sub>''</tt>
+| : shift in x-direction to the STL model in <tt>''FILE<sub>i</sub>''</tt>
 |-
 | <tt>''Y<sub>i</sub>''</tt>
-| : Shift in y-direction to the STL model in <tt>''FILE<sub>i</sub>''</tt>
+| : shift in y-direction to the STL model in <tt>''FILE<sub>i</sub>''</tt>
 |-
 | <tt>''Z<sub>i</sub>''</tt>
-| : Shift in z-direction to the STL model in <tt>''FILE<sub>i</sub>''</tt>
+| : shift in z-direction to the STL model in <tt>''FILE<sub>i</sub>''</tt>
 |}
+<u>Notes:</u>
+*Special <tt>''MAT<sub>i</sub>''</tt> entry: the material entries can be replaced by "<tt>fill ''UNI<sub>i</sub>''</tt>", in which case the region is filled by another universe, <tt>''UNI<sub>i</sub>''</tt>.
+*For a practical example: [[Stanford critical bunny]].
   '''solid 3'''
@@ Line 1,583: / Line 2,904: @@
 {|
 | <tt>''INTERFACE_FILE''</tt>
-| : Path to the [[Multi-physics_interface#Unstructured_mesh_based_interface_and_geometry_definition_.28type_9.29|interface file]] containing the rest of the parameters
+| : path to the [[Multi-physics_interface#Unstructured_mesh_based_interface_and_geometry_definition_.28type_9.29|interface file]] containing the rest of the parameters
 |}
+<u>Notes:</u>
+*For more information on the unstructured mesh based geometry see [[Unstructured mesh based input]].
+*For a practical example: [[Simple umsh 8 cubes input]].
 === src (source definition)<span id="src"></span> ===
@@ Line 1,591: / Line 2,916: @@
            [ [[#src_sw|'''sw''']] ''WGT'' ]
            [ [[#src_sc|'''sc''']] ''CELL'' ]
+          [ [[#src_su|'''su''']] ''UNI'' ]
            [ [[#src_sm|'''sm''']] ''MAT'' ]
            [ [[#src_sp|'''sp''']] ''X'' ''Y'' ''Z'' ]
@@ Line 1,596: / Line 2,922: @@
            [ [[#src_sy|'''sy''']] ''Y<sub>MIN</sub>'' ''Y<sub>MAX</sub>'' ]
            [ [[#src_sz|'''sz''']] ''Z<sub>MIN</sub>'' ''Z<sub>MAX</sub>'' ]
+          [ [[#src_srad|'''srad''']] ''R<sub>MIN</sub>'' ''R<sub>MAX</sub>'' ]
            [ [[#src_ss|'''ss''']] ''SURF'' ]
            [ [[#src_sd|'''sd''']] ''U'' ''V'' ''W'' ]
+          [ [[#src_sa|'''sa''']] ''PHI'' ]
            [ [[#src_se|'''se''']] ''E'' ]
-           [ [[#src_sb|'''sb''']] ''N'' ''E<sub>1</sub>'' ''WGT<sub>1</sub>'' ''E<sub>2</sub>'' ''WGT<sub>2</sub>'' ... ]
+           [ [[#src_sb|'''sb''']] ''N'' ''INTT'' ''E<sub>1</sub>'' ''WGT<sub>1</sub>'' ''E<sub>2</sub>'' ''WGT<sub>2</sub>'' ... ]
            [ [[#src_sr|'''sr''']] ''NUC'' ''MT'' ]
            [ [[#src_st|'''st''']] ''T<sub>MIN</sub>'' ''T<sub>MIN</sub>'' ]
@@ Line 1,605: / Line 2,933: @@
            [ [[#src_si|'''si''']] ''N'' ''P<sub>1</sub>'' ''P<sub>2</sub>'' ... ]
            [ [[#src_sg|'''sg''']] ''MAT'' ''MODE'' ]
-Source definition. The first parameter:
+Source definition. The two first parameters:
 {|
+| <tt>''NAME''</tt>
+|: source name
+|-
 | <tt>''PART''</tt>
 | : particle type (n = neutron, p = photon)
 |}
-is optional in single particle simulations. The remaining parameters are defined by separate key words followed by the input values.
+The remaining parameters are defined by separate key words followed by the input values.
+<u>Notes:</u>
+*The particle type <tt>''PART''</tt> is optional in single particle simulations.
+*A single source card may include one or several source types.
+<u>Source types:</u>
 Source weight (<tt>'''sw'''</tt>):<span id="src_sw"></span>
@@ Line 1,636: / Line 2,973: @@
 <u>Notes:</u>
 *Setting a source cell is one of the options that can be applied to define the spatial distribution of source particles.
-*The selection is based on rejection sampling, and if the source cell occupies a small volume of the geometry, the sampling efficiency can be increased by defining a bounding box around the cell using the <tt>''sx''</tt>, <tt>''sy''</tt> and <tt>''sz''</tt> options.
+*The selection is based on rejection sampling, and if the source cell occupies a small volume of the geometry, the sampling efficiency can be increased by defining a bounding box/(vertical) cylinder around the cell (using the <tt>'''sx'''</tt>, <tt>'''sy'''</tt> and <tt>'''sz'''</tt> or <tt>'''sp'''</tt>, <tt>'''srad'''</tt> and <tt>'''sz'''</tt> options, respectively).
 *If no spatial distribution is defined, particles are sampled uniformly over the geometry.
+Source universe (<tt>'''su'''</tt>):<span id="src_su"></span>
+{|
+| <tt>''UNI''</tt>
+| : universe inside which the source points are sampled
+|}
@@ Line 1,649: / Line 2,994: @@
 <u>Notes:</u>
 *Setting a source material is one of the options that can be applied to define the spatial distribution of source particles.
-*The selection is based on rejection sampling, and if the source material occupies a small volume of the geometry, the sampling efficiency can be increased by defining a bounding box around the region using the <tt>''sx''</tt>, <tt>''sy''</tt> and <tt>''sz''</tt> options.
+*The selection is based on rejection sampling, and if the source material occupies a small volume of the geometry, the sampling efficiency can be increased by defining a bounding box/(vertical) cylinder around the cell (using the <tt>'''sx'''</tt>, <tt>'''sy'''</tt> and <tt>'''sz'''</tt> or <tt>'''sp'''</tt>, <tt>'''srad'''</tt> and <tt>'''sz'''</tt> options, respectively).
 *If no spatial distribution is defined, particles are sampled uniformly over the geometry.
@@ Line 1,657: / Line 3,002: @@
 {|
 | <tt>''X''</tt>, <tt>''Y''</tt>, <tt>''Z''</tt>,
-| : coordinates of the source point
+| : coordinates of the source point [in cm]
 |}
@@ Line 1,665: / Line 3,010: @@
-Source boundaries (<tt>'''sx'''</tt>, <tt>'''sy'''</tt> and <tt>'''sz'''</tt>):<span id="src_sy"></span><span id="src_sx"></span><span id="src_sz"></span>
+Source boundaries (<tt>'''sx'''</tt>, <tt>'''sy'''</tt>, <tt>'''sz'''</tt> and <tt>'''srad'''</tt>):<span id="src_sy"></span><span id="src_sx"></span><span id="src_sz"></span><span id="src_srad"></span>
 {|
 | <tt>''X<sub>MIN</sub>''</tt>, <tt>''X<sub>MAX</sub>''</tt>
-| : Boundaries on X-axis
+| : boundaries on X-axis [in cm]
 |-
 | <tt>''Y<sub>MIN</sub>''</tt>, <tt>''Y<sub>MAX</sub>''</tt>
-| : Boundaries on Y-axis
+| : boundaries on Y-axis [in cm]
 |-
 | <tt>''Z<sub>MIN</sub>''</tt>, <tt>''Z<sub>MAX</sub>''</tt>
-| : Boundaries on Z-axis
+| : boundaries on Z-axis [in cm]
+|-
+| <tt>''R<sub>MIN</sub>''</tt>, <tt>''R<sub>MAX</sub>''</tt>
+| : radial boundaries [in cm]
 |-
 |}
 <u>Notes:</u>
-*Source boundaries are used to define a bounding box inside which the source particles are sampled.
+*Source boundaries are used to define a bounding box/(vertical) cylinder inside which the source particles are sampled.
+*The radial boundaries are centered around the point defined by <tt>'''sp'''</tt> and can be used in combination with <tt>'''sz'''</tt>.
 *Can be used in combination with cell and material sources to increase the sampling efficiency.
 *If no bounding box is defined, particles are sampled uniformly over the geometry.
-Surface source (<tt>'''ss'''</tt>):<span id="src_ss"></span>
+Source surface (<tt>'''ss'''</tt>):<span id="src_ss"></span>
 {|
@@ Line 1,694: / Line 3,043: @@
 <u>Notes:</u>
 *The surface source is currently limited to infinite vertical cylinder (<tt>'''cyl'''</tt>) and sphere (<tt>'''sph'''</tt>) surface types.
-*Particles are started in the direction of the inward surface normal.
+*The default behavior is that particles are started in the direction of the outward surface normal.
+*Positive and negative surface entries refer to neutrons being emitted in the direction of the positive and negative surface normal, respectively.
+** Meaning: positive = outward, negative = inward - same convention as for the surface detectors.
@@ Line 1,708: / Line 3,059: @@
 *If no directional dependence is defined, the direction of source particles is sampled isotropically.
+Source angular-aperture (<tt>'''sa'''</tt>):<span id="src_sa"></span>
+{|
+| <tt>''PHI''</tt>
+| : polar angle [in degrees]
+|}
+<u>Notes</u>
+*The source angular-aperture option can be set to define the semi-aperture with respect a direction.
+*The option requires the definition of a unidirectional source (<tt>'''sd'''</tt>).
 Source energy (<tt>'''se'''</tt>):<span id="src_se"></span>
@@ Line 1,713: / Line 3,075: @@
 {|
 | <tt>''E''</tt>
-| : energy of source particles
+| : energy of source particles [in MeV]
 |}
@@ Line 1,727: / Line 3,089: @@
 | <tt>''N''</tt>
 | : number of bins
+|-
+| <tt>''INTT''</tt>
+| : interpolation (0 = line spectrum, 1 = histogram, 2 = lin-lin, 4 = log-lin)
 |-
 | <tt>''E<sub>n</sub>''</tt>
-| : upper boundary of the energy bin
+| : upper boundary of the energy bin [in MeV]
 |-
 | <tt>''WGT<sub>n</sub>''</tt>
@@ Line 1,738: / Line 3,103: @@
 *This option allows defining an arbitrary source spectrum in the form of tabular data.
 *The bins are entered in the order of ascending energy, and weight of the first bin must be set to zero.
-*The interpolation between the bins is either linear (positive weight entries) or logarithmic (negative weight entries).
+*Interpolation is given in a separate parameter from version 2.1.31 on.
+*Here, a simple test input that demonstrates the [[Source energy spectrum definition test case|source spectrum definition]].
 Source reaction (<tt>'''sr'''</tt>):<span id="src_sr"></span>
@@ Line 1,748: / Line 3,113: @@
 |-
 | <tt>''MT''</tt>
-| : reaction number
+| : reaction number identifier
 |}
@@ Line 1,762: / Line 3,127: @@
 {|
 | <tt>''T<sub>MIN</sub>''</tt>, <tt>''T<sub>MAX</sub>''</tt>
-| : time boundaries
+| : time boundaries [in s]
 |}
@@ Line 1,781: / Line 3,146: @@
 <u>Notes:</u>
-*Source files allow defining arbitrary distributions by reading the particle coordinates, direction, energy, weight and time from a file.
+*Source files allow defining arbitrary distributions by reading the particle coordinates, direction, energy, weight and time from a file: [<tt> x y z u v w E wgt t </tt>] .
-*Source files can be produced using the <tt>'''df'''</tt> entry of [[#det_df|detector cards]] or the [[#set csw|set csw]] option.
+*Source files can be produced using the <tt>'''df'''</tt> entry of [[#det_df|detector cards]], or the [[#set csw|set csw]] or [[#set gsw|set gsw]] options.
@@ Line 1,806: / Line 3,171: @@
 {|
 | <tt>''MAT''</tt>
-| : material name or -1
+| : material name
 |-
 | <tt>''MODE''</tt>
@@ Line 1,813: / Line 3,178: @@
 <u>Notes:</u>
-*Radioactive decay source combines material compositions to decay data read from ENDF format libraries and forms the normalized source distribution automatically.
+*Radioactive decay source combines material compositions to decay data read from ENDF format<ref name="endf" /> libraries and forms the normalized source distribution automatically.
-*Material compositions can be defined manually, or read from binary restart files produced by a burnup or activation calculation (see the [[#set rfw|set rfw]] and [[#set rfr|set rfr]] options).
+*Radioactive material:
-*If the material name is replaced by -1, source points are started from all radioactive materials.
+**Material compositions can be defined manually, or read from binary restart files produced by a burnup or activation calculation (see the [[#set rfw|set rfw]] and [[#set rfr|set rfr]] options).
-*The analog sampling mode preserves the average number of particles produced in radioactive decay, but may lead to poor sampling efficiency in geometries with both low and high-active materials.
+**There is a special entry for the <tt>''MAT''</tt> parameter:
-*The implicit sampling mode preserves the total statistical weight of emitted particles and produces a uniform source distribution over activated materials.
+***"<tt>-1</tt>": to refer to all radioactive materials in the calculation system
-*In version 2.1.28 the source is limited to photon line spectra.
+*Sampling mode:
-*The calculation produces an additional output file <tt>[input]_gsrc.m</tt> that contains the source spectra.
+**The analog sampling mode preserves the average number of particles produced in radioactive decay, but may lead to poor sampling efficiency in geometries with both low and high-active materials.
+**The implicit sampling mode preserves the total statistical weight of emitted particles and produces a uniform source distribution over activated materials.
+*The radiation types included are discrete line and continuum spectra for photon and neutron reactions.
+**The radioactive decay source in version 2.1.28 and earlier is limited to photon line spectra.
+*The calculation produces an additional output file <tt>[input]_gsrc.m</tt> or <tt>[input]_nsrc.m</tt> that contains the gamma/neutron source spectra, respectively.
 *See [[Radioactive decay source, practical example|practical example]] for more information.
 === strans (surface transformation)<span id="strans"></span> ===
-See [[#trans (transformations)|transformations]].
+Defines surface transformations. Shortcut for "<tt>trans s</tt>".
+<u>Notes:</u>
+*The parameters associated with the transformation follow the standard transformation cards syntax without '''trans''' <tt>''TYPE''</tt> identifier.
+*See [[#trans (transformations)|transformations]].
 === surf (surface definition)<span id="surf"></span> ===
@@ Line 1,859: / Line 3,232: @@
   '''thermstoch''' ''NAME'' ''TEMP'' ''LIB<sub>1</sub>'' ''LIB<sub>2</sub>''
-Defines thermal scattering data that can be linked to nuclides using input entry '''moder''' in the [[#mat (material definition)|material cards]]. When using thermal scattering data together with TMS on-the-fly temperature treatment, the third input value of the therm card is 0. In this case, Serpent interpolates the thermal scattering data automatically to the local temperature, as defined either using the '''tms''' input entry in the material definition or via the multi-physics interface.
+Defines thermal scattering data that can be linked to nuclides using input entry '''moder''' in the [[#mat (material definition)|material cards]]. Input values:
-Input values:
 {|
 | <tt>''NAME''</tt>
@@ Line 1,870: / Line 3,242: @@
 |-
 | <tt>''TEMP''</tt>
-| : temperature to which the thermal scattering data is interpolated
+| : temperature to which the thermal scattering data is interpolated [in K]
 |}
 <u>Notes:</u>
+* On-the-fly thermal motion sampling (TMS) temperature treatment:
-*When using on-the-fly interpolation of thermal scattering data, <tt>''LIB<sub>i</sub>''</tt> must cover the whole temperature range in which the materials appear in the geometry. I.e. extrapolation of the data is not supported.
+**It requires the third value of the therm card to be set to "<tt>0</tt>"
-*Thermal scattering data is interpolated using the methodology of makxsf code
+**The thermal scattering data is automatically interpolated to the local temperature.
-*The interpolation can be performed using the stochastic mixing approach with '''thermstoch'''. This interpolation mode is not available for on-the-fly interpolation.
+**The local temperature is either defined using:
+*** the '''tms''' entry in the material card (see [[#mat|mat card]])
+*** the multi-physics interface (see [[#ifc|ifc card]]), where the temperature limits are defined using the '''tft''' entry in the material card (see [[#mat|mat card]])
+**The thermal scattering libraries <tt>''LIB<sub>i</sub>''</tt> must cover the whole range in which the materials appear in the geometry, i.e. data extrapolation is not supported.
+*Interpolation:
+**Thermal scattering data is interpolated using the methodology of makxsf code<ref name="makxsf">Brown, F. B. ''"The makxsf Code with Doppler Broadening"'', Los Alamos National Laboratory Tech. Rep., LA-UR-06-7002, Los Alamos, NM, [https://mcnp.lanl.gov/pdf_files/TechReport_2006_LANL_LA-UR-06-7002_Brown.pdf 2006]</ref>.
+**Alternatively, the interpolation can be performed using the stochastic mixing approach with the '''thermstoch''' entry.
+***This interpolation mode doesn't support on-the-fly interpolation.
+*The continuous S(&alpha;, &beta;) formalism:
+**It is available from version 2.1.32 on.
+**The on-the-fly temperature treatment is available from version 2.2.0 and on.
 === tme (time binning definition)<span id="tme"></span> ===
@@ Line 1,897: / Line 3,279: @@
 |-
 | <tt>''LIM<sub>n</sub>''</tt>
-| : time bin boundaries in arbitrary binning
+| : time bin boundaries in arbitrary binning [in s]
 |-
 | <tt>''T<sub>min</sub>''</tt>
-| : minimum time boundary in uniform or log-uniform binning
+| : minimum time boundary in uniform or log-uniform binning [in s]
 |-
 | <tt>''T<sub>max</sub>''</tt>
-| : maximum time boundary in uniform or log-uniform binning
+| : maximum time boundary in uniform or log-uniform binning [in s]
 |}
 <u>Notes:</u>
-*The entered values are in seconds
 *The first limit in the arbitrary type (type = 1), is the lower bound of the first bin. The second limit is the upper bound of the first bin and so on.
 *Time binning is used with [[#det (detector definition)|detectors]] and [[Dynamic external source simulation mode|dynamic simulation mode]].
@@ Line 1,914: / Line 3,295: @@
 === trans (transformations)<span id="trans"></span> ===
-  '''trans''' ''TYPE'' ''UNIT'' ''LVL''
+  '''trans''' ''TYPE'' ''UNIT'' [ ''IDX'' ] ''LVL''
-  '''trans''' ''TYPE'' ''UNIT'' ''X'' ''Y'' ''Z''
+  '''trans''' ''TYPE'' ''UNIT'' [ ''IDX'' ] ''X'' ''Y'' ''Z''
-  '''trans''' ''TYPE'' ''UNIT'' ''X'' ''Y'' ''Z'' ''&theta;<sub>x</sub>'' ''&theta;<sub>y</sub>'' ''&theta;<sub>z</sub>'' ''ORD''
+  '''trans''' ''TYPE'' ''UNIT'' [ ''IDX'' ] ''X'' ''Y'' ''Z'' ''&theta;<sub>x</sub>'' ''&theta;<sub>y</sub>'' ''&theta;<sub>z</sub>'' ''ORD''
-  '''trans''' ''TYPE'' ''UNIT'' ''X'' ''Y'' ''Z'' ''&alpha;<sub>1</sub>'' ''&alpha;<sub>2</sub>'' ''&alpha;<sub>3</sub>'' ''&alpha;<sub>4</sub>'' ''&alpha;<sub>5</sub>'' ''&alpha;<sub>6</sub>'' ''&alpha;<sub>7</sub>'' ''&alpha;<sub>8</sub>'' ''&alpha;<sub>9</sub>'' ''ORD''
+  '''trans''' ''TYPE'' ''UNIT'' [ ''IDX'' ] ''X'' ''Y'' ''Z'' ''&alpha;<sub>1</sub>'' ''&alpha;<sub>2</sub>'' ''&alpha;<sub>3</sub>'' ''&alpha;<sub>4</sub>'' ''&alpha;<sub>5</sub>'' ''&alpha;<sub>6</sub>'' ''&alpha;<sub>7</sub>'' ''&alpha;<sub>8</sub>'' ''&alpha;<sub>9</sub>'' ''ORD''
-  '''trans''' ''TYPE'' ''UNIT'' '''rot''' ''X<sub>0</sub>'' ''Y<sub>0</sub>'' ''Z<sub>0</sub>'' ''I'' ''J'' ''K'' ''&beta;''
+  '''trans''' ''TYPE'' ''UNIT'' [ ''IDX'' ] '''rot''' ''X<sub>0</sub>'' ''Y<sub>0</sub>'' ''Z<sub>0</sub>'' ''I'' ''J'' ''K'' ''&beta;''
-Defines surface, universe or fill transformation. Input values:
+Defines surface, universe, fill, lattice, detector mesh or source transformation. Input values:
 {|
 | <tt>''TYPE''</tt>
-| : type of transformation (S = surface transformation, F = fill transformation, U = universe transformation)
+| : type of transformation (S = surface, F = fill, U = universe, L = lattice, D = detector mesh, SR = source)
 |-
 | <tt>''UNIT''</tt>
-| : surface, cell or universe name to which the transformation is applied
+| : surface, cell, universe, lattice, detector mesh or source name to which the transformation is applied
+|-
+| <tt>''IDX''</tt>
+| : index number of lattice position to which the lattice transformation (type L) is applied
 |-
 | <tt>''LVL''</tt>
@@ Line 1,937: / Line 3,321: @@
 |-
 | <tt>''X'',''Y'',''Z''</tt>
-| : translation vector
+| : translation vector [in cm]
 |-
 | <tt>''&theta;<sub>x</sub>'' ''&theta;<sub>y</sub>'' ''&theta;<sub>z</sub>''</tt>
-| : rotation angles with respect to x-, y- and z-axes (in degrees)
+| : rotation angles with respect to x-, y- and z-axes [in degrees]
 |-
 | <tt>''&alpha;<sub>1</sub>'' ... ''&alpha;<sub>9</sub>''</tt>
@@ Line 1,949: / Line 3,333: @@
 |-
 | <tt>''X<sub>0</sub>'',''Y<sub>0</sub>'',''Z<sub>0</sub>''</tt>
-| : Origin of vector defining rotation axis.
+| : origin of vector defining rotation axis [in cm]
 |-
 | <tt>''I'',''J'',''K''</tt>
-| : Components of vector defining rotation axis.
+| : components of vector defining rotation axis.
 |-
 | <tt>''&beta;''</tt>
-| : Angle around rotation axis defined by a vector (in degrees). '''NB: In Serpent 2.1.29 positive values correspond to rotation to the negative mathematical direction and vice versa.'''
+| : angle around rotation axis defined by a vector [in degrees].
+|-
+|}
+The possible transformation types are:
+::{| class="wikitable" style="text-align: left;"
+! Type
+! Description
+! Notes
+|-
+| <tt>s</tt>
+| surface
+|
+|-
+| <tt>f</tt>
+| fill
+| It is applied in the universe filling the given cell.
+|-
+| <tt>u</tt>
+| universe
+| ''Special type'': <u>level</u> transformation,  in which the coordinates in the given universe are obtained relative to geometry level <tt>''LVL''</tt>.
+|-
+| <tt>l</tt>
+| lattice
+| It requires to provide the index number <tt>''IDX''</tt> of lattice position to which the transformation is applied.
+|-
+| <tt>d</tt>
+| mesh detector
+| It is associated to mesh detectors (such as '''dx''', '''dy''', '''dz''', '''dh''', '''dn''' or '''dmesh''', see [[#det|det card]])
+|-
+| <tt>sr</tt>
+| source
+| It is inverted compared to how surface, universe, etc. are handled
 |-
 |}
 <u>Notes:</u>
+*Translations: by providing the translation vector.
+**By default translations are applied before rotations, and the order can be switched using the <tt>''ORD''</tt> parameter.
+*Rotations:
+**With respect x-/y-/z-axes:  either by providing the three angles with respect to the three coordinate axes, or by defining the rotation matrix.
+***In the second case Serpent applies vector multiplication: <math>\vec{r'} = \bold{A} \vec{r}</math>
+:::where <math>\vec{r}</math> and <math>\vec{r'}</math> are the position vectors before and after the operation and coefficients <tt>''&alpha;<sub>1</sub>'' ... ''&alpha;<sub>9</sub>''</tt> define the 3 by 3 matrix <math>\bold{A}</math>.
+:*With respect a general axes: using the '''rot''' keyword and associated syntax.
+:**In Serpent 2.1.29, a positive value of ''&beta;'' corresponds to rotation to the negative mathematical direction and vice versa.
+*Backwards compatibility:
+**To preserve backwards compatibility, input parameters "<tt>strans</tt>", "<tt>utrans</tt>", "<tt>ftrans</tt>" and "<tt>dtrans</tt>" without the following type identifier are also accepted for defining surface, universe, fill and detector mesh transformations, respectively.
+**To preserve compatibility with Serpent 1, parameter "<tt>trans</tt>" without type identifier defines a universe transformation.
-*Fill transformation is applied in the universe filling the given cell.
+=== transb (burnup transformation)<span id="transb"></span> ===
-*Level transformation is a special type of universe transformation, in which the coordinates in the given universe are obtained relative to geometry level <tt>''LVL''</tt>.
-*By default translations are applied before rotations, and the order can be switched using the <tt>''ORD''</tt> parameter.
-*Rotations can be defined either by providing the three angles with respect to the three coordinate axes, or by defining the rotation matrix. In the second case Serpent applies vector multiplication <math>\vec{r'} = \bold{A} \vec{r}</math> where <math>\vec{r}</math> and <math>\vec{r'}</math> are the position vectors before and after the operation and coefficients <tt>''&alpha;<sub>1</sub>'' ... ''&alpha;<sub>9</sub>''</tt> define the 3 by 3 matrix <math>\bold{A}</math>.
-*To preserve backwards compatibility, input parameters "strans", "utrans" and "ftrans" without the following type identifier are also accepted for defining surface, universe and fill transformations, respectively. To preserve compatibility with Serpent 1, parameter "trans" without type identifier defines a universe transformation.
-=== transv and transa (velocity and acceleration transformations)<span id="transa"></span><span id="transv"></span> ===
+ '''transb''' ''STEP'' [ <''trans''> ]
- '''transv''' ''TYPE'' ''UNIT'' [ '''tlim''' ''T<sub>0</sub>'' ''T<sub>1</sub>'' ''T<sub>TYPE</sub>'' ] ''V<sub>X</sub>'' ''V<sub>Y</sub>'' ''V<sub>Z</sub>''
+Defines burnup-dependent surface, universe, fill, lattice, detector mesh or source transformation. Input values:
- '''transa''' ''TYPE'' ''UNIT'' [ '''tlim''' ''T<sub>0</sub>'' ''T<sub>1</sub>'' ''T<sub>TYPE</sub>'' ] ''A<sub>X</sub>'' ''A<sub>Y</sub>'' ''A<sub>Z</sub>''
+{|
+| <tt>''STEP''</tt>
+| : depletion step (positive value = burnup [in MWd/kg], negative value = time [in d])
+|-
+| <tt><''trans''></tt>
+| : list of parameters associated with the transformation
+|}
+<u>Notes:</u>
+*The parameters associated with the transformation follow the standard transformation cards syntax without '''trans''' identifier.
+*Standard properties applicable to regular or non-time dependent transformations apply.
+*For more information, see detailed description on transformations ([[#trans (transformations)|trans card]]).
+*Geometry plots associated with burnup transformations are featured from version 2.2.1 and on.
+=== transv and transa (velocity and acceleration transformations)<span id="transa"></span><span id="transv"></span> ===
+ '''transv''' ''TYPE'' ''UNIT'' [ ''IDX'' ] [ '''tlim''' ''T<sub>0</sub>'' ''T<sub>1</sub>'' ''T<sub>TYPE</sub>'' ] ''V<sub>X</sub>'' ''V<sub>Y</sub>'' ''V<sub>Z</sub>''
+ '''transa''' ''TYPE'' ''UNIT'' [ ''IDX'' ] [ '''tlim''' ''T<sub>0</sub>'' ''T<sub>1</sub>'' ''T<sub>TYPE</sub>'' ] ''A<sub>X</sub>'' ''A<sub>Y</sub>'' ''A<sub>Z</sub>''
-Defines surface, universe or fill transformation. Input values:
+Defines a time-dependent surface, universe, fill, lattice, detector mesh or source transformation. Input values:
 {|
 | <tt>''TYPE''</tt>
-| : type of transformation (S = surface transformation, F = fill transformation, U = universe transformation)
+| : type of transformation (S = surface, F = fill, U = universe, L = lattice, D = detector mesh, SR = source)
 |-
 | <tt>''UNIT''</tt>
-| : surface, cell or universe name to which the transformation is applied
+| : surface, cell, universe, lattice, detector mesh or source name to which the transformation is applied
+|-
+| <tt>''IDX''</tt>
+| : index number of lattice position to which the lattice transformation (type L) is applied
 |-
 | <tt>''T<sub>0</sub>''</tt>
-| : beginning time of the transformation
+| : beginning time of the transformation [in s]
 |-
 | <tt>''T<sub>1</sub>''</tt>
-| : end time of the transformation
+| : end time of the transformation [in s]
 |-
 | <tt>''T<sub>TYPE</sub>''</tt>
@@ Line 1,993: / Line 3,436: @@
 |-
 | <tt>''V<sub>X</sub>'',''V<sub>Y</sub>'',''V<sub>Z</sub>''</tt>
-| : Initial velocity vector
+| : initial velocity vector [in cm/s]
 |-
 | <tt>''A<sub>X</sub>'',''A<sub>Y</sub>'',''A<sub>Z</sub>''</tt>
-| : Initial acceleration vector
+| : initial acceleration vector [in cm/s<sup>2</sup>]
 |}
 <u>Notes:</u>
-*Fill transformation is applied in the universe filling the given cell.
+*Standard properties applicable to regular or non-time dependent transformations apply.
 *The transformation is updated at the simulation time-interval boundaries.
-*See [[UGM 2016 Moving geometry]].
+** The time-dependent transformation evaluation method option is defined by the [[#set_transtime|set transtime]] option.
-*See [[Rotating Translating STL Bunny]].
+*For practical examples:
+**See [[UGM 2016 Moving geometry]].
+**See [[Rotating Translating STL Bunny]].
+===umsh (unstructured mesh-based geometry definition)<span id="umsh"></span> ===
+ ''UNI'' ''BGUNI''
+ ''MESH_SPLIT'' ''MESH_DIM'' ''SZ<sub>1</sub>'' ''SZ<sub>2</sub>'' ... ''SZ<sub>MESH_DIM</sub>''
+ ''POINTS_FILE''
+ ''FACES_FILE''
+ ''OWNER_FILE''
+ ''NEIGHBOUR_FILE''
+ ''MATERIALS_FILE''
+Defines an unstructured mesh-based geometry. Input values:
+{|
+| <tt>''UNI''</tt>
+| : universe name for the unstructured mesh-based geometry
+|-
+| <tt>''BGUNI''</tt>
+| : name of the background universe filling all undefined space
+|-
+| <tt>''MESH_SPLIT''</tt>
+| : splitting criterion for the adaptive search mesh (maximum number of geometry cells in search mesh cell)
+|-
+| <tt>''MESH_DIM''</tt>
+| : number of levels in the adaptive search mesh
+|-
+| <tt>''SZ<sub>i</sub>''</tt>
+| : size of the search mesh at level <tt>''i''</tt>
+|-
+| <tt>''POINTS_FILE''</tt>
+| : path to the unstructured mesh points file
+|-
+| <tt>''FACES_FILE''</tt>
+| : path to the unstructured mesh faces file
+|-
+| <tt>''OWNER_FILE''</tt>
+| : path to the unstructured mesh owner file
+|-
+| <tt>''NEIGHBOUR_FILE''</tt>
+| : path to the unstructured mesh neighbour file
+|-
+| <tt>''MATERIALS_FILE''</tt>
+| : path to the unstructured mesh materials file
+|}
+<u>Notes:</u>
+*For more information, see the description of the '''solid''' description of how to create a 3D unstructured mesh-based universe geometry ([[#solid|solid card]], type 1).
 === utrans (universe transformation)<span id="utrans"></span> ===
-See [[#trans (transformations)|transformations]].
+Defines universe transformations. Shortcut for "<tt>trans u</tt>".
+<u>Notes:</u>
+*The parameters associated with the transformation follow the standard transformation cards syntax without '''trans''' <tt>''TYPE''</tt> identifier.
+*See [[#trans (transformations)|transformations]].
+=== voro (stochastic Voronoi tessellation geometry definition)<span id="voro"></span> ===
+ '''voro''' ''UNI<sub>0</sub>'' ''UNI<sub>bg</sub>'' ''R<sub>0</sub>'' '''-1''' ''NP'' ''UNI<sub>1</sub>'' ''VF<sub>1</sub>'' [ ''UNI<sub>2</sub>'' ''VF<sub>2</sub>'' ... ]
+ '''voro'''  ''UNI<sub>0</sub>'' ''UNI<sub>bg</sub>'' ''R<sub>0</sub>'' ''FILE''
+Defines a stochastic Voronoi tessellation geometry. Input values:
+{|
+| <tt>''UNI<sub>0</sub>''</tt>
+|: universe name for the Voronoi medium
+|-
+| <tt>''UNI<sub>bg</sub>''</tt>
+|: background universe name filling all undefined space
+|-
+| <tt>''R<sub>0</sub>''</tt>
+|: test radius [in cm]
+|-
+| <tt>''NP''</tt>
+|: number of seed points
+|-
+| <tt>''UNI<sub>m</sub>''</tt>
+|: sub-universe name for the ''m''-th random fragmented polyhedral zone
+|-
+| <tt>''VF<sub>m</sub>''</tt>
+|: volume fraction associated to ''m''-th random fragmented polyhedral zone
+|-
+| <tt>''FILE''</tt>
+|: input file containing the Voronoi data
+|}
+The <u>syntax of the file</u> containing the Voronoi seed points data is:
+::{| class="toccolours" style="text-align: left;"
+|-
+| ''X<sub>1</sub>'' ''Y<sub>1</sub>'' ''Z<sub>1</sub>'' ''UNI<sub>1</sub>''
+|-
+| ''X<sub>2</sub>'' ''Y<sub>2</sub>'' ''Z<sub>2</sub>'' ''UNI<sub>1</sub>''
+|-
+| ...
+|-
+| ''X<sub>N</sub>'' ''Y<sub>N</sub>'' ''Z<sub>N</sub>'' ''UNI<sub>1</sub>''
+|-
+| ''X<sub>N+1</sub>'' ''Y<sub>N+1</sub>'' ''Z<sub>N+1</sub>'' ''UNI<sub>2</sub>''
+|-
+| ...
+|}
+where:
+{|
+| <tt>''X<sub>n</sub>'', ''Y<sub>n</sub>'', ''Z<sub>n</sub>''</tt>
+|: seed points coordinates [in cm]
+|-
+| <tt>''UNI<sub>m</sub>''</tt>
+|: sub-universe name for the ''m''-th random zone associated to the given seed point
+|}
+<u>Notes:</u>
+*The input consists of a list of seed points and associated sub-universes filling the Voronoi cells Alternatively, the number of seeds points and volume fractions of each zone can be provided, letting Serpent sample the positions randomly.
+**The advantage of the first option is that the distribution can be defined explicitly, taking into account, for example, the varying level of fragmentation closer to the boundaries.
+*The cell search and surfaces distances are based on search mesh and local short-list of points to reduce the computational effort.
+**The search mesh is conditioned by the test radius, which should enclose the Voronoi polyhedral cells.
+***Too small radius may result in geometry errors as some points are excluded from all the search mesh cells in which they should be.
+***Too large radius may results in including points in cells that do not actually intersect with the polyhedral boundary.
+*The <tt>''DENS''</tt> parameter in the [[#set mcvol|mcvol]] input option can be switched "<tt>on</tt>" to compensate the non-preservation of the volume fractions provided as input due to the randomness of the seed points.
+**It applies calculated scaling factors to material densities preserving the original masses (scaling factor = volume MC routine / volume given)
 === wwgen (response matrix based importance map solver)<span id="wwgen"></span> ===
@@ Line 2,016: / Line 3,579: @@
        ''MIN<sub>2</sub>'' ''MAX<sub>2</sub>'' ''SZ<sub>2</sub>''
        ''MIN<sub>3</sub>'' ''MAX<sub>3</sub>'' ''SZ<sub>3</sub>''
-       ''DET<sub>1</sub>'' ''w<sub>1</sub>'' [ ''DET<sub>2</sub>'' ''w<sub>2</sub>'' ... ]
+       ''DET<sub>1</sub>'' ''W<sub>1</sub>'' [ ''DET<sub>2</sub>'' ''W<sub>2</sub>'' ... ]
   '''wwgen''' ''NAME'' ''LIM'' ''NI'' ''MOD'' ''ERG'' ''MSH''
@@ Line 2,023: / Line 3,586: @@
        ''LIM<sub>21</sub>'' ''LIM<sub>22</sub>'' ...
        ''LIM<sub>31</sub>'' ''LIM<sub>32</sub>'' ...
-       ''DET<sub>1</sub>'' ''w<sub>1</sub>'' [ ''DET<sub>2</sub>'' ''w<sub>2</sub>'' ... ]
+       ''DET<sub>1</sub>'' ''W<sub>1</sub>'' [ ''DET<sub>2</sub>'' ''W<sub>2</sub>'' ... ]
+ '''wwgen''' ''NAME'' ''LIM'' ''NI'' ''MOD'' ''ERG'' ''MSH''
+      ''X<sub>0</sub>'' ''Y<sub>0</sub>''
+      ''P'' ''NX'' ''NY''
+      ''MIN<sub>3</sub>'' ''MAX<sub>3</sub>'' ''SZ<sub>3</sub>''
+      ''DET<sub>1</sub>'' ''W<sub>1</sub>'' [ ''DET<sub>2</sub>'' ''W<sub>2</sub>'' ... ]
 Defines the parameters for importance map calculation. Input values:
@@ Line 2,039: / Line 3,607: @@
 |-
 | <tt>''MOD''</tt>
-| : solution mode (use 1 for now)
+| : solution mode (1 = single detector, 2 = multiple detectors, 3 = global variance reduction)
 |-
 | <tt>''ERG''</tt>
@@ Line 2,045: / Line 3,613: @@
 |-
 | <tt>''MSH''</tt>
-| : mesh type (1  = Cartesian, 2 = Cylindrical, 6 = unevenly-spaced xyz, 8 = unevenly spaced cylindrical)
+| : mesh type (1  = Cartesian, 2 = Cylindrical, 4 = x-type hexagonal, 5 = y-type hexagonal, 6 = unevenly-spaced xyz, 8 = unevenly spaced cylindrical)
 |-
 | <tt>''MIN<sub>n</sub>''</tt>
-| : minimum mesh boundary (n:th coordinate)
+| : minimum mesh boundary (''n''-th coordinate)
 |-
 | <tt>''MAX<sub>n</sub>''</tt>
-| : maximum mesh boundary (n:th coordinate)
+| : maximum mesh boundary (''n''-th coordinate)
 |-
 | <tt>''SZ<sub>n</sub>''</tt>
-| : number of mesh cells (n:th coordinate)
+| : number of mesh cells (''n''-th coordinate)
 |-
 | <tt>''LIM<sub>nm</sub>''</tt>
-| : m:th boundary of n:th coordinate)
+| : mesh boundary ''m''-th (''n''-th coordinate)
+|-
+| <tt>''X<sub>0</sub>'', ''Y<sub>0</sub>''</tt>
+| : mesh center of hexagonal mesh (currently must be centered at the origin)
+|-
+| <tt>''P''</tt>
+| : hexagonal cell pitch
+|-
+| <tt>''NX'', ''NY''</tt>
+| : hexagonal mesh size
 |-
 | <tt>''DET<sub>i</sub>''</tt>
 | : detectors used as target response functions
 |-
-| <tt>''w<sub>i</sub>''</tt>
+| <tt>''W<sub>i</sub>''</tt>
 | : weight factors for detector scores
 |}
@@ Line 2,068: / Line 3,645: @@
 <u>Notes:</u>
-*The solution mode provides various options on how the responses are used for calculating the importances. For now, only mode 1 is supported (calculate importances directly with respect to the response).
+*The solution mode provides various options on how the responses are used for calculating the importances.
+*The detector entries can be left out in global variance reduction mode (<tt>''MOD''</tt> = 3), in which case the mesh is optimized to uniformly populate the entire geometry.
 *Cartesian and cylindrical mesh are defined by outer mesh boundaries and number of mesh cells.
 *Unevenly-spaced meshes are defined by providing the mesh cell boundaries separately.
 *The coordinate axes 1, 2 and 3 in Cartesian mesh refer to (x,y,z) and in cylindrical mesh to (r,&theta;,z), with &theta; given in degrees.
+*The hexagonal mesh is defined by mesh center, cell pitch, number of cells in the radial dimensions (similar to the hexagonal lattice) and axial binning.
 *The mesh must be defined slightly larger than the geometry (the mesh boundaries should not coincide with the geometry boundaries).
 *Source points located on mesh cell boundaries cause fatal errors.
@@ Line 2,077: / Line 3,656: @@
 *The importance mesh is printed in file <tt>[input].wwd</tt>.
 *Importance (weight window) meshes are read using the [[#wwin (weight window mesh definition)|wwin card]].
-*This capability is still <u>very much under development</u>. The input syntax may be revised at some point.
+*See also practical examples on [[Variance reduction]].
 === wwin (weight window mesh definition)<span id="wwin"></span> ===
   '''wwin''' ''NAME''
-     [ '''wf''' ''FILE'' ''FMT'' ''SB'' ''TYPE'' ]
+     [ [[#wwin_wf|'''wf''']] ''FILE'' ''FMT'' ]
-     [ '''wn''' ''F'' ''X'' ''Y'' ''Z'' ''E'' ]
+    [ [[#wwin_wn|'''wn''']] ''F'' ''X'' ''Y'' ''Z'' ''E'' ]
-     [ '''wx''' ''C'' ''G'' ]
+    [ [[#wwin_wx|'''wx''']] ''C'' ''G'' ]
+    [ [[#wwin_wt|'''wt''']] ''SB'' ''TYPE'' ''MIN'' ''MAX'' ]
+     [ [[#wwin_wi1|'''wi''']] ''ITP'' ''NI'' ''WWG<sub>1</sub>'' ''DF<sub>1</sub>'' ''WWG<sub>2</sub>'' ''DF<sub>2</sub>'' ... ]
+     [ [[#wwin_wi2|'''wi''']] ''ITP'' ''NI'' ''WWG'' ''NX'' ''NY'' ''NZ'' ''NLOOP'' ''NTRK'' ''ISPL'' ''NSPL'' ''DSPL<sub>1</sub>'' ''SX<sub>1</sub>'' ''SY<sub>1</sub>'' ''SZ<sub>1</sub>'' ''DSPL<sub>2</sub>'' ''SX<sub>2</sub>'' ''SY<sub>2</sub>'' ''SZ<sub>2</sub>'' ...]
-Defines a weight window mesh for variance reduction. Input values:
+Defines a weight window mesh for variance reduction. The first parameter:
 {|
 | <tt>''NAME''</tt>
 | : a unique name to identify the mesh
-|-
+|}
+The remaining parameters are defined by separate key words followed by the input values.
+<u>Notes:</u>
+*Only works in external source simulation mode.
+*Importance (weight window) meshes can be generated by running the [[#wwgen (response matrix based importance map solver)|response matrix based solver]], or read in MCNP WWINP format<ref>Kulesza, J. A. (ed.), ''“MCNP code version 6.3.0 Theory & User Manual: Appendix A Mesh-Based WWINP, WWOUT, and WWONE File Format,”'' LA-UR-22-30006, Rev. 1, Los Alamos National Laboratory [https://mcnp.lanl.gov/pdf_files/TechReport_2022_LANL_LA-UR-22-30006Rev.1_KuleszaAdamsEtAl.pdf (2022)].</ref>.
+*Importance maps can be visualized using the [[#plot (geometry plot definition)|geometry plotter]].
+*See also [[#set wwb|set wwb]] and [[#set maxsplit|set maxsplit]] for setting options for weight windows, splitting and Russian roulette.
+*See also practical examples on [[Variance reduction]].
+<u>Weight-window mesh paramters:</u>
+Mesh file (<tt>'''wf'''</tt>):<span id="wwin_wf"></span>
+{|
 | <tt>''FILE''</tt>
 | : file path and name of the importance mesh file
 |-
 | <tt>''FMT''</tt>
-| : file format (1 = mesh produced by Serpent importance map generator, 2 = MCNP weight window mesh file)
+| : file format (1 = mesh produced by Serpent importance map generator, 2 = MCNP WWINP format weight window mesh file)
-|-
+|}
-| <tt>''SB''</tt>
-| : option to set source biasing on (1/yes) or off (0/no) with Serpent-generated importance maps
+<u>Notes:</u>
-|-
-| <tt>''TYPE''</tt>
+*By default the importance map is read from the mesh file and used as-is, the additional options are provided for adjustments.
-| : unused type parameter for Serpent-generated importance maps (set to 2)
+*Currently the MCNP format only supports simple mesh types (no sub-mesh).
-|-
+Mesh normalization (<tt>'''wn'''</tt>):<span id="wwin_wn"></span>
+{|
 | <tt>''F''</tt>
 | : importance for renormalization
@@ Line 2,111: / Line 3,714: @@
 |-
 | <tt>''E''</tt>
-| : energy used for renormalization
+| : energy used for renormalization [in MeV]
-|-
+|}
+<u>Notes:</u>
+*The importances can be renormalized by fixing the value at a given position and energy.
+Mesh adjustment (<tt>'''wx'''</tt>):<span id="wwin_wx"></span>
+{|
 | <tt>''C''</tt>
 | : constant multiplier for adjusting importances
@@ Line 2,122: / Line 3,734: @@
 <u>Notes:</u>
-*By default the importance map is read from the mesh file and used as-is, the additional options are provided for adjustments.
+*The importances can be adjusted by constant multiplier <tt>''C''</tt> and exponential factor <tt>''G''</tt> such that <math>F' = CF^G</math>.
-*The importances can be renormalized using the '''wn''' option by fixing the value at a given position and energy.
-*The importances can be adjusted using the '''wx''' option by constant multiplier <tt>''C''</tt> and exponential factor <tt>''G''</tt> such that <math>F' = CF^G</math>.
-*Currently the MCNP format only supports regular mesh type (uniform spacing).
-*Only works in external source simulation mode.
-*Source biasing works only for limited source types.
-*Importance (weight window) meshes can be generated by running the [[#wwgen (response matrix based importance map solver)|response matrix based solver]].
-*Importance maps can be visualized using the [[#plot (geometry plot definition)|geometry plotter]].
-*This capability is still <u>very much under development</u>. The input syntax may be revised at some point.
-== Input options ==
+Types and options (<tt>'''wt'''</tt>):<span id="wwin_wt"></span>
+{|
+| <tt>''SB''</tt>
+| : option to set source biasing on (1/yes) or off (0/no) with Serpent-generated importance maps
+|-
+| <tt>''TYPE''</tt>
+| :  bounds type for Serpent-generated weight-windows (1 = averaged, 2 = segment-wise)
+|-
+| <tt>''MIN''</tt>
+| : minimum truncation limit for importances
+|-
+| <tt>''MAX''</tt>
+| : maximum truncation limit for importances
+|}
+<u>Notes:</u>
+*Source biasing is currently not available
+Weight-window iterations, fixed mesh (<tt>'''wi'''</tt>):<span id="wwin_wi1"></span>
+{|
+| <tt>''ITP''</tt>
+| : iteration type (1 = fixed mesh)
+|-
+| <tt>''NI''</tt>
+| : number of iterations between Monte Carlo simulation and the response matrix solver
+|-
+| <tt>''WWG<sub>i</sub>''</tt>
+| :  name of the WWG-structure used in the iteration
+|-
+| <tt>''DF<sub>i</sub>''</tt>
+| :  global density factor
+|}
+<u>Notes:</u>
+*The fixed mesh option (<tt>''ITP''</tt> = 1) allows performing iterations using a single or multiple meshes generated using the [[#wwgen (response matrix based importance map solver)|response matrix based solver]].
+*The global density factor is a multiplier applied to all material densities.
+Weight-window iterations, adaptive mesh (<tt>'''wi'''</tt>):<span id="wwin_wi2"></span>
+{|
+| <tt>''ITP''</tt>
+| : iteration type (2 = geometry-based adaptation, 3 = tracking-based adaptation)
+|-
+| <tt>''NI''</tt>
+| : number of iterations between Monte Carlo simulation and the response matrix solver
+|-
+| <tt>''WWG''</tt>
+| :  name of the WWG-structure used in the iteration
+|-
+| <tt>''NX''</tt>
+| : number of x-divisions for the adaptive mesh
+|-
+| <tt>''NY''</tt>
+| : number of y-divisions for the adaptive mesh
+|-
+| <tt>''NZ''</tt>
+| : number of z-divisions for the adaptive mesh
+|-
+| <tt>''NLOOP''</tt>
+| : number of outer iteration loops in generation of adaptive mesh
+|-
+| <tt>''NTRK''</tt>
+| : number of tracks per loop in generation of adaptive mesh
+|-
+| <tt>''ISPL''</tt>
+| : importance split criterion
+|-
+| <tt>''NSPL''</tt>
+| : neighbor split criterion
+|-
+| <tt>''DSPL<sub>i</sub>''</tt>
+| : density split criterion (positive value = atomic density [in b<sup>-1</sup>cm<sup>-1</sup>], negative values = mass density [in g/cm<sup>3</sup>])
+|-
+| <tt>''SZ<sub>i</sub>''</tt>
+| : minimum cell dimension [in cm]
+|}
+<u>Notes:</u>
+*The adaptive mesh option (<tt>''ITP''</tt> = 2 or 3) starts with a coarse base mesh, and refines the resolution iteratively.
+*There are two adaptive mesh options:
+**In the geometry-based option (<tt>''ITP''</tt> = 2) Serpent covers the geometry with <tt>''NTRK''</tt> random tracks and splits cells according to density criteria.
+**In the tracking-based option (<tt>''ITP''</tt> = 3) the tracks are started from the source instead. The procedure is repeated <tt>''NLOOP''</tt> times.
+*Cell splitting is defined using the <tt>''NX'', ''NY''</tt> and <tt>''NZ''</tt> options.
+**For example <tt>''NX''</tt> = 2, <tt>''NY''</tt> = 2, <tt>''NZ''</tt> = 2 results in each cell being split to 8 sub-cells (octree mesh).
+**For 2D meshes the <tt>''NZ''</tt> parameter must be set to "1".
+*Splitting is carried out recursively, until limiting criteria are met.
+**The importance split criterion defines the maximum relative difference between the importances of two adjacent cells.
+***If the criterion is not met, both cells are split.
+**The neighbor split criterion defines the maximum number of neighbor allowed for a cell.
+***If the criterion is not met, the cell is split.
+**The <tt>''DSPL''</tt> and <tt>''SZ<sub>i</sub>''</tt> parameters define upper density boundaries and minimum cell sizes for stopping the splits.
+== Input options<span id="input options"></span> ==
 Input options are used to set various calculation parameters that are not included in the main input cards. Each option is identified by key word "set". Optional values are enclosed within square brackets.
+=== set absrate ===
+ '''set absrate''' ''A'' [ ''MAT'' ]
+Sets normalization to total absorption rate. Input values:
+{|
+| <tt>''F''</tt>
+| : number of  neutrons absorbed per second [in neutrons/s]
+|-
+| <tt>''MAT''</tt>
+| : dummy parameter
+|}
+<u>Notes:</u>
+*Normalization is needed to relate the Monte Carlo reaction rate estimates to a user-given parameter.
+*Absorption includes all reactions in which the incident neutron is lost, i.e. all capture reactions and fission.
+*The default normalization:
+**It is set to unit total loss rate (neutron transport) and to unit total source rate (photon transport).
+**In coupled neutron-photon transport simulations the normalization is driven by the neutron normalization.
+*For other normalization options, see: [[#set power|set power]], [[#set powdens|set powdens]], [[#set flux|set flux]], [[#set genrate|set genrate]], [[#set fissrate|set fissrate]], [[#set lossrate|set lossrate]], [[#set srcrate|set srcrate]], [[#set sfrate|set sfrate]].
+*See also Section 5.8 of [http://montecarlo.vtt.fi/download/Serpent_manual.pdf Serpent 1 User Manual].
 === set acelib ===
@@ Line 2,149: / Line 3,876: @@
 *If the file path contains special characters it is advised to enclose it within quotes.
-*A default directory path can be set by defining environment variable SERPENT_DATA. The code looks for cross section directory files in this path if not found at the absolute.
+*A default directory path can be set by defining environment variable <tt>SERPENT_DATA</tt>. The code looks for cross section directory files in this path if not found at the absolute.
-*A default cross section directory file can be set by defining environment variable SERPENT_ACELIB. This file will be used if no other path is given with '''set acelib'''.
+*A default cross section directory file can be set by defining environment variable <tt>SERPENT_ACELIB</tt>.
+**This file will be used if no other path is given with '''set acelib'''.
 === set adf ===
-  '''set adf''' ''UNI SURF SYM''
+  '''set adf''' ''UNI SURF SYM [ENF]''
-Sets parameters for the calculation of assembly discontinuity factors. Input values:
+Sets parameters for the calculation of assembly discontinuity factors (ADFs) and related net and partial currents. Input values:
 {|
@@ Line 2,166: / Line 3,894: @@
 | <tt>''SYM''</tt>
 | : symmetry option ([[ADF symmetry options|see separate list]])
+|-
+| <tt>''ENF''</tt>
+| : option to switch on (1/yes) or off (0/no) a non-standard calculation approach. The default option is "<tt>off</tt>"
 |}
 <u>Notes:</u>
+*ADFs are calculated in the few-group structure for the group constant generation (see [[#set nfg|set nfg]] option).
+*The calculation of ADFs is currently allowed only for infinite planes and square and hexagonal prisms.
+**Sign moments of net and partial currents are not scored for [[Surface_types#Regular_prisms|Y-type infinite/truncated hexagonal prisms]].
-*The surface enclosing the universe can be super-imposed (i.e. not part of the geometry definition), but it must enclose the <u>entire</u> universe.
+*Methodology:
-*When the universe is surrounded by zero net-current (reflective) boundary conditions, the ADF's are calculated as the ratios of surface- and volume-averaged heterogeneous flux.
+**If the universe is surrounded by zero net-current (reflective) boundary conditions, the ADFs are calculated as the ratios of surface- and volume-averaged heterogeneous flux.
-*When the net current is non-zero, the calculation is based on the ratio of surface-averaged homogeneous and heterogeneous flux. The homogeneous flux is obtained from a [[Diffusion flux solver|built-in diffusion flux solver]].
+**If the net current is non-zero, the calculation is based on the ratio of surface-averaged homogeneous and heterogeneous flux.
-*Calculation parameters for the diffusion flux solver can be set using the [[#set dfsol|set dfsol]] option.
+***The homogeneous flux is obtained from a [[Diffusion flux solver|built-in diffusion flux solver]].
-*Calculation of ADF's is currently allowed only for planes and infinite square and hexagonal prisms.
+**The default behaviour (standard approach) can be changed via the <tt>''ENF''</tt> parameter:
-*Symmetry options are used to average out the statistical variation in the ADF's, which might otherwise lead to systematic errors in core calculations. It is important that the options are used only when the geometry has the corresponding symmetry.
+***If the flag is "<tt>on</tt>", it enforces a flat homogeneous flux distribution based on mean heterogeneous flux, skipping the diffusion solver, regardless of net-current value.
-*See separate description of [[Output parameters#Assembly discontinuity factors|output parameters]] in the <tt>[input]_res.m</tt>.
+***The <tt>''ENF''</tt> parameter should be switched on only in rare cases (with understanding of the implications of the calculation setup).
-*The ADF's can be printed to the [[Automated_burnup_sequence#Output|group constant output]] with [[Input syntax manual#set_coefpara|set coefpara]].
+*Setup:
+**The surface is treated as super-imposed on the geometry, i.e. its parameters (coordinates) are relative to the root universe (see [[Input_syntax_manual#set_root|set root]] option).
+***The surface enclosing the universe can be super-imposed (i.e. not part of the geometry definition), but it must enclose the <u>entire</u> universe.
+**The symmetry options are used to average out the statistical variation in the ADFs, which might otherwise lead to systematic errors in core calculations.
+***It is important that the options are used only when the geometry has the corresponding symmetry.
+**The calculation parameters for the diffusion flux solver can be set using the [[#set dfsol|set dfsol]] option.
+*The ADFs are written in:
+** <tt>[input]_res.m</tt> output file: [[Output parameters#Assembly discontinuity factors|homogenized group constants/ADFs]] sub-section
+** <tt>[input].coe</tt> ouput file, via the [[Input syntax manual#set_coefpara|set coefpara]] option: [[Automated_burnup_sequence#Output|automated burnup sequence/coefficient matrix]] output.
 === set alb ===
@@ Line 2,197: / Line 3,941: @@
 <u>Notes:</u>
-*When this option is set, Serpent calculates both total albedos (ratio of currents) and partial albedos (response matrix).
+*The option enables the calculation of both total albedos (ratio of currents) and partial albedos (response matrix).
-*The current direction is given relative to the surface normal vectors
+*Albedos are calculated in the few-group structure for the group constant generation (see [[#set nfg|set nfg]] option).
-*The universe is needed only for labelling the results in the output files.
+*Setup:
-*See separate description of [[Output parameters#Albedos|output parameters]].
+**The universe is needed only for labelling the results in the output files.
+**The surface is treated as super-imposed on the geometry, i.e. its parameters (coordinates) are relative to the root universe (see [[Input_syntax_manual#set_root|set root]] option).
+***The surface enclosing the universe can be super-imposed (i.e. not part of the geometry definition), but it must enclose the <u>entire</u> universe.
+**The current direction is given relative to the surface normal vectors.
+*The albedo estimates are written in:
+** <tt>[input]_res.m</tt> output file: [[Output parameters#Albedos|homogenized group constants/albedos]] sub-section
+** <tt>[input].coe</tt> ouput file, via the [[Input syntax manual#set_coefpara|set coefpara]] option: [[Automated_burnup_sequence#Output|automated burnup sequence/coefficient matrix]] output.
 === set arr ===
@@ Line 2,209: / Line 3,959: @@
 {|
 | <tt>''MODEN''</tt>
-| : mode for neutrons (0 = no reactions included, 1 = include only reactions that affect neutron balance, 2 = include all reactions)
+| : mode for neutrons (0 = no reactions included, 1 = include only reactions that affect neutron balance, 2 = include all reactions). (default value: 0)
 |-
 | <tt>''MODEG''</tt>
-| : mode for photons (0 = no reactions included, 1 = include all reactions)
+| : mode for photons (0 = no reactions included, 1 = include all reactions). (default value: 0)
 |}
 <u>Notes:</u>
-*Analog reaction rates are calculated by counting sampled events and printed in a separate output file.
+*Analog reaction rates are calculated by counting sampled events and printed in a separate output file <tt>[input]_arr[bu].m</tt>, where "<tt>bu</tt>" is the burnup step.
-*See detailed description on the [[Description of output files#Reaction rate output|reaction rate output file]].
+*For more information, see the detailed description on the [[Description of output files#Reaction rate output|reaction rate output file]].
-=== set bc ===
+=== set ba ===
-  '''set bc''' ''MODE''
+  '''set ba''' ''ZAI<sub>1</sub> ZAI<sub>2</sub> ...''
-Sets the boundary conditions for all outer boundaries of the geometry. Input values:
+Defines isotopes handled separately as burnable absorbers. Input values:
 {|
-| <tt>''MODE''</tt>
+| <tt>''ZAI<sub>n</sub>''</tt>
-| : boundary type (1 = vacuum, 2 = reflective, 3 = periodic)
+| : nuclide identifiers ([[Definitions, units and constants#definitions|ZAI]])
 |}
+<u>Notes:</u>
-  '''set bc''' ''MODE ALB''
+*This input parameter can be used to separate the transmutation chains.
-Sets the boundary conditions with albedo for all outer boundaries of the geometry. Input values:
+**Some burnup applications require separate treatment for isotopes that are used as burnable absorbers but also produced in fission.
+*Isotope handled as the burnable absorber is created by duplicating the original and renaming it as ''ZAI<sub>n</sub> + 1000''.
+**For Gd-155, for example, the fission product isotope would be assigned ZAI 641550 and the burnable absorber ZAI 642550.
+*The input parameter defines the entire transmutation chain.
+**Listing Gd-isotopes 641540 641550 641560 641570 641580 creates a transmutation path from Gd-154 to Gd-158.
+**Listing only the main absorbers (641550 641570) produces a different result, since the capture products of Gd-155 and Gd-157 are lost.
+=== set bala ===
+  '''set bala''' ''OPT''
+Sets OpenMP load balancing on or off. Input values:
 {|
-| <tt>''MODE''</tt>
+| <tt>''OPT''</tt>
-| : boundary type (1 = vacuum, 2 = reflective, 3 = periodic)
+| : probability to store particles in common queue (0 = off, non-zero = on)
-|-
-| <tt>''ALB''</tt>
-| : albedo
 |}
+<u>Notes:</u>
+*Load balancing may improve OpenMP parallel scalability in calculations with significant branching.
+**Most typically related to coupled neutron/photon calculations or variance reduction.
+*Default value:
+**It is "<tt>on</tt>" with <tt>''OPT''</tt>= 1 with weight-window/variance reduction calculations and dynamic/time-dependent calculation modes.
+**Otherwise, it is set "<tt>off</tt>".
+**Before version 2.2.0, the default behaviour was always "<tt>off</tt>".
+*When this option is set, the random number sequence is no longer preserved.
+=== set bc ===
+ '''set bc''' ''MODE''
+ '''set bc''' ''MODE ALB''
   '''set bc''' ''MODEX MODEY MODEZ''
-Sets the boundary conditions separately for x-, y- and z-directions. Input values:
+ '''set bc''' ''MODEX MODEY MODEZ ALB''
+Sets the boundary conditions (BCs). Input values:
 {|
+| <tt>''MODE''</tt>
+| : boundary condition type in all directions
+|-
 | <tt>''MODEX''</tt>
-| : boundary type in x-direction (1 = vacuum, 2 = reflective, 3 = periodic)
+| : boundary condition type in x-direction
 |-
 | <tt>''MODEY''</tt>
-| : boundary type in y-direction (1 = vacuum, 2 = reflective, 3 = periodic)
+| : boundary condition type in y-direction
 |-
 | <tt>''MODEZ''</tt>
-| : boundary type in z-direction (1 = vacuum, 2 = reflective, 3 = periodic)
+| : boundary condition type in z-direction
 |-
+| <tt>''ALB''</tt>
+| : albedo
 |}
- '''set bc''' ''MODEX MODEY MODEZ ALB''
+The possible boundary condition types are:
-Sets the boundary conditions with albedo separately for x-, y- and z-directions. Input values:
+::{| class="wikitable" style="text-align: left;"
+! Type
-{|
+! Description
-| <tt>''MODEX''</tt>
+! Notes
-| : boundary type in x-direction (1 = vacuum, 2 = reflective, 3 = periodic)
 |-
-| <tt>''MODEY''</tt>
+| <tt>1, black</tt>
-| : boundary type in y-direction (1 = vacuum, 2 = reflective, 3 = periodic)
+| vacuum boundary condition(s)
+| the particle is killed
 |-
-| <tt>''MODEZ''</tt>
+| <tt>2, reflective</tt>
-| : boundary type in z-direction (1 = vacuum, 2 = reflective, 3 = periodic)
+| repeated (reflective) boundary condition(s)
+| the particle is reflected back into the geometry
+|-
+| <tt>3, periodic</tt>
+| repeated (periodic) boundary condition(s)
+| the particle is moved to the opposite side of the geometry
 |-
-| <tt>''ALB''</tt>
-| : albedo
 |}
 <u>Notes:</u>
+*The default boundary condition is vacuum in all directions.
-*The boundary conditions can be set either for all directions at once (single parameter) or x-, y- and z-directions separately (three parameters). Albedos are provided by adding one more parameter in the list.
+*Direction-wise boundary conditions:
-*The default boundary condition is vacuum (= 1) in all directions.
+**Boundary conditions can be set for all directions at once: <tt>''MODE''</tt>.
-*Albedo boundary conditions are invoked by multiplying the particle weight with factor ''ALB'' each time a reflective or periodic boundary is hit.
+**Boundary conditions can be set for x-/y-/z- direction separately: <tt>''MODEX''</tt>, <tt>''MODEY''</tt>, and <tt>''MODEZ''</tt>
-*Repeated boundary conditions (reflective or periodic) are based on universe transformations, which limits outer boundary to surfaces that form regular lattices (square and hexagonal prisms, rectangles, cubes and cuboids).
+*Boundary conditions can be defined with albedos by adding one additional parameter in the list, <tt>''ALB''</tt>.
-*Repeated boundary conditions are applied on the first surface of outside cells (see definition of outside cells in the [[#cell (cell definition)|cell card]])
+**Albedo boundary conditions are invoked by multiplying the particle weight with factor <tt>''ALB''</tt> each time a reflective or periodic boundary is hit.
-*For symmetry purposes Serpent provides the [[#set usym|universe symmetry option]].
+*Repeated boundary conditions (reflective or periodic):
-*For more information, see [[Boundary conditions|detailed description on boundary conditions]].
+**They are based on universe transformations, which limits outer boundary to surfaces that form regular lattices (square and hexagonal prisms, rectangles, cubes and cuboids).
+**They are applied on the first surface of outside cells (see definition of outside cells in the [[#cell (cell definition)|cell card]])
+*For universe symmetry options, see the [[#set usym|set usym]] option.
+*For more information, see the detailed description on the [[Boundary conditions|Boundary conditions]].
 === set blockdt ===
@@ Line 2,295: / Line 4,081: @@
 <u>Notes:</u>
-*This option is used to override selection of tracking mode based on the probability threshold (see [[#set dt|set dt]]) in individual materials.
+*This option is used to override selection of tracking mode based on the probability threshold (see [[#set dt|set dt]] option) in individual materials.
-*Use of delta-tracking can be forced in individual materials using [[#set forcedt|set forcedt]].
+*The use of delta-tracking can be forced in individual materials using [[#set forcedt|set forcedt]] option.
 *For more information on tracking modes, see the detailed description on [[delta- and surface-tracking]].
 *''Note to developers: should have different lists for neutrons and photons?''
@@ Line 2,311: / Line 4,097: @@
 <u>Notes:</u>
-*Isomeric branching data libraries are standard ENDF format files containing energy-dependent branching ratios. The data is read from ENDF files 9 and 10.
-*Serpent uses [[Default isomeric branching ratios|constant branching ratios]] by default. The default values can be overridden using the [[#set isobra|set isobra]] option. Energy-dependent data read read from ENDF format files overrides the constant ratios.
 *If the file path contains special characters it is advised to enclose it within quotes.
 *A default directory path can be set by defining environment variable SERPENT_DATA. The code looks for decay data files in this path if not found at the absolute.
-*See also: [[Branching ratio example|example input]]
+*Isomeric branching data libraries are standard ENDF format<ref name="endf">Trkov, A., Herman, M. and Brown, D. A. ''"ENDF-6 Formats Manual."'' CSEWG Document ENDF-102 / BNL-90365-2009 Rev. 2 [https://www.nndc.bnl.gov/endf-b8.0/endf-manual-viii.0.pdf (2018)]</ref> files containing energy-dependent branching ratios. The data is read from ENDF files 9 and 10.
-*Example data from the [http://virtual.vtt.fi/virtual/montecarlo/misc/sss_jeff31a.bra JEFF-3.1 activation file]
+*Serpent uses [[Default isomeric branching ratios|constant branching ratios]] by default.
+**The default values can be overridden using the [[#set isobra|set isobra]] option. In which case, the energy-dependent data read from ENDF format files override the constant ratios.
+*See a practical example on how to evaluate branching ratios: [[Branching ratio example|example input]].
+**The isomeric branching  data library corresponds to the JEFF-3.1 activation file [[File:JEFF-3.1_activation_file.tgz]].
+=== set branchless ===
+ '''set branchless''' ''OPT'' [ ''WGT_LOW'' ''WGT_HIGH'' ]
+Option that enables the branchless collision method for variance reduction. Input values:
+{|
+| <tt>''OPT''</tt>
+| :  option to switch calculation on (1/yes) or off (0/no). The default option is "<tt>off</tt>".
+|-
+| <tt>''WGT_LOW''</tt>
+| : weight lower-boundary (default value: 0.2)
+|-
+| <tt>''WGT_HIGH''</tt>
+| : weight upper-boundary (default value: 10.0)
+|}
+<u>Notes:</u>
+*The branchless algorithm suppresses the variability due to the simultaneous propagation of the several branches associated to a fission event
+*The branchless method uses analog scattering combined with forced fission so that after each collision, the neutron is either a scattering neutron or a fission neutron.
+**In a non-multiplying method, the branchless method behaves as implicit capture.
+*The branchless method sets the following simulation configuration: reaction sampling ([[#set nphys|set nphys 1 1 1]]), reaction modes ([[#set impl|set impl 0 1 1]]), and population control ([[#set combing|set combing 1]]), overriding any user-defined option.
+*The current implementation does not support the use of the branchless collision method combined with the unresolved resonance probability table sampling (see [[#set ures|set ures]] option).
 === set bumode ===
-  '''set bumode''' ''MODE'' [ ''ORDER'' ]
+  '''set bumode''' ''MODE'' [ ''ORDER'' ''SSD'' ]
 Sets the burnup calculation mode. Input values:
@@ Line 2,327: / Line 4,136: @@
 {|
 | <tt>''MODE''</tt>
-| : burnup calculation mode
+| : burnup calculation mode (default value: 2 = CRAM)
 |-
 | <tt>''ORDER''</tt>
-| : CRAM order
+| : CRAM order (default value: 14 - 14 PFD CRAM)
+|-
+| <tt>''SSD''</tt>
+| : number of substeps for CRAM decay steps (default value: 0 = use TTA)
 |}
 The possible settings for mode are:
-{| class="wikitable" style="text-align: left;"
+::{| class="wikitable" style="text-align: left;"
 ! Mode
 ! Description
@@ Line 2,346: / Line 4,158: @@
 |}
-The CRAM order parameter can only be given when choosing the cram mode. The possible settings for CRAM order are:
+The CRAM order parameter can only be given when choosing the CRAM mode. The possible settings for CRAM order are:
-{| class="wikitable" style="text-align: left;"
+::{| class="wikitable" style="text-align: left;"
 ! CRAM order
-|-
 | <tt>2</tt>
-|-
 | <tt>4</tt>
-|-
 | <tt>6</tt>
-|-
 | <tt>8</tt>
-|-
 | <tt>10</tt>
-|-
 | <tt>12</tt>
-|-
 | <tt>14</tt>
-|-
 | <tt>16</tt>
+| <tt>-16</tt>
+| <tt>-48</tt>
 |}
 <u>Notes:</u>
-*The default setting for the burnup calculation mode is CRAM.
+*Positive values refer to PFD form of CRAM. Negative values of CRAM order mean using IPF form of CRAM with order of the absolute value of the parameter.
-*Default value for the CRAM order is 14.
+*Decay calculations (see [[#dep (depletion history)|dep (depletion history)]]) and burnup calculations with very low flux are always calculated with TTA disregarding this input before version 2.1.32.
-*The CRAM order must be divisible by 2 and any values greater than 16 are considered to be 16.
+**The latter, very low flux condition, only applies to calculations not involving continuous reprocessing.
+*Positive values of <tt>''SSD''</tt> enforce usage of CRAM with given number of substeps. A zero value of <tt>''SSD''</tt> enforces usage of TTA.
+*The Serpent 1 <tt>''MODE''</tt> 3, a variation TTA method, in which cyclic transmutation chains are handled by inducing small variations in the coefficients instead of solving the extended TTA equations, is overwritten by the standard TTA method <tt>''MODE''</tt> 1.
+=== set bunorm ===
+ '''set bunorm''' ''NORM''
+Sets the burnup calculation normalization mode if it is not bound to a single material. Input values:
+{|
+| <tt>''NORM''</tt>
+| : burnup calculation normalization mode (1 = all materials, 2 = burnable materials, 3 = non-burnable materials). (default value: 1)
+|}
 === set ccmaxiter ===
@@ Line 2,380: / Line 4,199: @@
 {|
 | <tt>''NITER''</tt>
-| : number of iterations.
+| : number of iterations (default value: 1 = no iteration)
 |}
 <u>Notes:</u>
-*Default maximum number of iterations is 1 (no iteration).
 *The iteration is stopped when either the maximum number of iterations or the maximum active neutron population (set with [[#set ccmaxpop|set ccmaxpop]]) has been simulated.
-*See [[Coupled multi-physics calculations]] for further information.
+*For more information, see the detailed description on [[Coupled multi-physics calculations|Couple multi-physics calculations]].
 === set ccmaxpop ===
@@ Line 2,396: / Line 4,214: @@
 {|
 | <tt>''CPOP''</tt>
-| : total active population to simulate.
+| : total active population to simulate (default value: [[Definitions, units and constants#Constants|INFTY]]/1E6)
 |}
 <u>Notes:</u>
-*Default maximum population is [[Definitions, units and constants#Constants|INFTY]]/1e6.
 *The iteration is stopped when either the maximum number of iterations (set with [[#set ccmaxiter|set ccmaxiter]]) or the maximum active neutron population has been simulated.
 *Only the population simulated during active cycles is included in this amount.
 *This is mostly useful if the neutron population per iteration is not constant.
-*See [[Coupled multi-physics calculations]] for further information.
+*For more information, see the detailed description on [[Coupled multi-physics calculations|Couple multi-physics calculations]].
+=== set cdop ===
+ '''set cdop''' ''OPT''
+Sets the Doppler broadening method for the energy spectrum of the scattered photons. Input values:
+{|
+| <tt>''OPT''</tt>
+| : option to set Doppler broadening method off (0/no) or on (1/yes). The default option is "<tt>on</tt>".
+|}
+<u>Notes:</u>
+*If the Doppler broadening method is switched "<tt>off</tt>", the incoherent scattering function approximation is used for calculating the energy.
+*In both cases, the direction of the photon is calculated using the incoherent scattering function.
+*The photon transport physics model is described in a related paper<ref name="photon">Kaltiaisenaho, T. ''"Photon transport physics in Serpent 2 Monte Carlo code."'' Comp. Phys. Comm., [https://doi.org/10.1016/j.cpc.2020.107143 ''252'' (2020) 107143.]</ref>
+=== set cea ===
+ '''set cea''' ''OPT''
+Sets the Compton electron angular distribution model on and off. Input values:
+{|
+| <tt>''OPT''</tt>
+| : option to set the Compton electron angular distribution model off (0/no) or on (1/yes). The default option is "<tt>on</tt>".
+|}
+<u>Notes:</u>
+*Electron travels in the direction of the momentum transfer vector. This is equal to the free-electron scattering angle when Doppler broadening is not used.
+*The photon transport physics model is described in a related paper<ref name="photon" />
 === set cfe ===
@@ Line 2,414: / Line 4,260: @@
 {|
 | <tt>''LN''</tt>
-| : minimum mean distance for scoring the CFE for neutrons
+| : minimum mean distance for scoring the CFE for neutrons [in cm] (default value: 20.0)
 |-
 | <tt>''TN''</tt>
-| : minimum mean time interval for scoring the CFE for neutrons
+| : minimum mean time interval for scoring the CFE for neutrons [in s]
 |-
 | <tt>''LG''</tt>
-| : minimum mean distance for scoring the CFE for photons
+| : minimum mean distance for scoring the CFE for photons [in cm] (default value: 20.0)
 |-
 | <tt>''TG''</tt>
-| : minimum mean time interval for scoring the CFE for photons
+| : minimum mean time interval for scoring the CFE for photons [in s]
 |}
 <u>Notes:</u>
-*The use of delta-tracking necessitates the use of CFE for scoring the integral reaction rates. The scoring is based on both real and virtual collision to improve the statistics in low density regions (and short time intervals).
+*The use of delta-tracking necessitates the use of CFE for scoring the integral reaction rates.
-*The minimum mean distance is the statistical mean-free-path (mfp) of collisions that contribute to the CFE. Collisions are more frequent if the physical mfp is shorter.
+**The scoring is based on both real and virtual collision to improve the statistics in low density regions (and short time intervals).
+*The minimum mean distance is the statistical mean-free-path (mfp) of collisions that contribute to the CFE.
+**Collisions are more frequent if the physical mfp is shorter.
 *In time-dependent simulations it may be more convenient to define the minimum mean time between two collisions, to get sufficient statistics for short time bins.
-*The default minimum mean scoring distance is 20 cm for both neutrons and photons. Adjusting the distance affects both statistics and running time, but it should be noted that <u>no studies have been performed on what the optimal value should be</u>.
+*Adjusting the distance affects both statistics and running time, but it should be noted that <u>no studies have been performed on what the optimal value should be</u>.
-*Only one criterion can be provided for each particle type. If distance is given, time must be set to -1 and vice versa.
+*Only one criterion can be provided for each particle type.
+**If distance is given, time must be set to "<tt>-1</tt>" and vice versa.
 *For more information on tracking modes and CFE, see the detailed descriptions on [[delta- and surface-tracking]] and [[Result estimators#Implicit estimators|result estimators]].
-*The collision flux estimator in Serpent is described in an article in Annals of Nuclear energy from 2017.<ref name="cfe">Leppänen, J.
+*The collision flux estimator methodology is described in a related paper.<ref name="cfe">Leppänen, J.
 ''"On the use of delta-tracking and the collision flux estimator in the Serpent 2 Monte Carlo particle transport code."'' Ann. Nucl. Energy [http://www.sciencedirect.com/science/article/pii/S0306454916311367 '''105''' (2017) 161-167].</ref>
 *In version 2.1.27 and earlier the name of this input option was "set minxs".
+=== set cmm ===
+ '''set cmm''' ''OPT''
+Sets calculation of diffusion coefficients using the cumulative migration method (CMM) on or off. Input values:
+{|
+| <tt>''OPT''</tt>
+| : option to switch CMM calculation on (1/yes) or off (0/no)
+|}
+<u>Notes:</u>
+*Methodology:
+**The CMM diffusion coefficients and transport cross sections are reasonable only when they are calculated over entire geometry:
+***The homogenized region covers the entire geometry and is surrounded by periodic or reflective boundary conditions.
+***This means that e.g. pin cell diffusion coefficients can not be calculated from a 2D fuel assembly calculation.
+**The CMM methodology was revised in version 2.1.31 so that the calculated values may be different than with previous versions.
+**One may try to approximate the CMM estimates with the transport correction for hydrogen for light water reactor applications (see [[#set trc|set trc]] option).
+*Setup:
+**CMM diffusion coefficients and transport cross sections  can be calculated also when using implicit capture reactions (see [[#set_impl|set impl]] option),  from version 2.1.31 and on.
+**The calculation of CMM estimates (diffusion coefficients and transport cross sections) might take considerable time. Switch "<tt>off</tt>" the evaluation if the data is not needed.
+**The use of private results array may be recommended when calculating CMM estimates (see [[#set_shbuf|set shbuf]] option).
+*The CMM diffusion coefficients <tt>CMM_DIFFCOEF</tt> and transport cross sections <tt>CMM_TRANSPXS</tt> estimates are written in:
+** <tt>[input]_res.m</tt> output file: [[Output parameters#Homogenized group constants|homogenized group constants]] section - diffusion parameters: for infinite spectrum and critical spectrum.
+** <tt>[input].coe</tt> ouput file, via the [[Input syntax manual#set_coefpara|set coefpara]] option: [[Automated_burnup_sequence#Output|automated burnup sequence/coefficient matrix]] output.
+*The cumulative migration method (CMM) is described in related papers<ref>Liu, Z., Smith, K., Forget, B. and Ortensi, J. ''"Cumulative migration method for computing rigorous diffusion coefficients and transport cross sections from Monte Carlo."'' Ann. Nuc. Energy, [https://doi.org/10.1016/j.anucene.2017.10.039 '''112''' (2016) 126-136]</ref><ref>Liu, Z., Smith, K. and Forget, B. ''"Group-wise Tally Scheme of Incremental Migration Area for Cumulative Migration Method."'' In Proceedings of the PHYSOR 2018 (2018) 2512-2523</ref>.
 === set coefpara ===
@@ Line 2,444: / Line 4,320: @@
 {|
 | <tt>''FMT''</tt>
-| : output format, currently used for including or excluding statistical errors (0 = not included, 1 = included)
+| : output format, currently used for including or excluding statistical errors (0 = not included, 1 = included). (default value: 0)
 |-
 | <tt>''PARAM<sub>n</sub>''</tt>
@@ Line 2,451: / Line 4,327: @@
 <u>Notes:</u>
+*List of parameters or detectors to include:
+**The available parameters are listed under [[Output parameters#Homogenized group constants|homogenized group constants]] in the description of the <tt>[input]_res.m</tt> output file.
+**Detectors are identified by the name assigned to them in the [[#det (detector definition)|det card]].
+*The group constant output file <tt>[input].coe</tt> is produced when the [[automated burnup sequence]] is invoked.
-*The group constant output file [input].coe is produced when the [[automated burnup sequence]] is invoked.
+=== set combing ===
-*The available parameters are listed under [[Output parameters#Homogenized group constants|homogenized group constants]] in the description of the [input]_res.m output file.
-*Detectors are identified by the name assigned to them in the [[#det (detector definition)|detector card]].
-=== set cmm ===
+  '''set combing''' ''MODE''
+Option that enables the combing approach for precursors population control as an alternative to Russian roulette and splitting in dynamic source simulations. Input values:
-  '''set cmm''' ''OPT''
-Sets calculation of diffusion coefficients using the cumulative migration method (CMM) on or off. Input values:
 {|
-| <tt>''OPT''</tt>
+| <tt>''MODE''</tt>
-| : option to switch CMM calculation on (1/yes) or off (0/no)
+| : combing population-control mode (0 = none, 1 = weight-based, 2 = emission-based). (default value: 0)
 |}
 <u>Notes:</u>
-*Calculation of [[Output_parameters#Diffusion_parameters|diffusion coefficients using CMM]] takes considerable time when the number of energy groups is large. This option allows switching the calculation off if the data is not needed.
+*The combing method can achieve variance reduction and save computer time by keeping the population size approximately constant over time steps.
+**In super-critical systems, it prevents the population from growing without bound.
+**In sub-critical systems, it prevents the population from dying.
+**In critical systems, it avoids the divergence of the variance of the population due to fluctuations of fission chains.
 === set comfile ===
@@ Line 2,485: / Line 4,364: @@
 *Setting up a communication mode will enable the coupled calculation mode.
-*For more information see: [[Coupled_multi-physics_calculations#External_coupling|External coupling]]
+*The communication options [[#set comfile|set comfile]], [[#set ppid|set ppid]] and [[#set pport|set pport]] are mutually exclusive, aka, multiple signalling modes are not allowed.
+*For more information, see the detailed description on [[Coupled_multi-physics_calculations#External_coupling|External coupling]]
 === set confi ===
@@ Line 2,494: / Line 4,374: @@
 {|
 | <tt>''OPT''</tt>
-| : option to set confidentiality flag on (1/yes) or off (0/no)
+| : option to set confidentiality flag on (1/yes) or off (0/no). The default option is "<tt>off</tt>"
 |}
 <u>Notes:</u>
-*This option can be used to label calculations as confidential. If the option is set, text "(CONFIDENTIAL)" is printed in the run-time output next to the [[#set title|calculation title]] and the value of variable CONFIDENTIAL_DATA in the [input]_res.m output file is set to 1.
+*This option can be used to label calculations as confidential. If the option is set, text "(CONFIDENTIAL)" is printed in the run-time output next to the [[#set title|calculation title]] and the value of variable CONFIDENTIAL_DATA in the <tt>[input]_res.m</tt> output file is set to "1".
+=== set coverxlib ===
+ '''set coverxlib''' ''LIB<sub>1</sub>'' [ ''LIB<sub>2</sub>'' ''LIB<sub>3</sub>'' ... ]
+Sets COVERX-format multi-group covariance data file paths. Input values:
+{|
+| <tt>''LIB<sub>n</sub>''</tt>
+| : file paths to multi-group covariance data files in the COVERX format<ref name="coverx">Wieselquist, W. A. and Lefebvre, R. A (ed.), ''"SCALE 6.3.1 User Manual: Sensitivity and Uncertainty Analysis - Appendix 6.3.4.1.6. COVERX format"'', ORNL/TM-SCALE-6.3.1, UT-Battelle, LLC, Oak Ridge National Laboratory, Oak Ridge, TN [https://scale-manual.ornl.gov/tsunami-ip-appAB.html#coverx-format (2023)]</ref>  (ASCII or binary)
+|}
+<u>Notes:</u>
+*It enables first-order uncertainty propagation by collapsing the covariance data with the evaluated sensitivities.
+**It applies the <u>Sandwich rule</u>: <math>\mathbf{Cov}^R_X \approx ({\overline{\mathbf{S}}}^R_X)^T {\overline{\overline{\mathbf{Cov}}}}^R_{X,X} \overline{\mathbf{S}}^R_X</math>
+:: where: <math>{\overline{\mathbf{S}}}^R_X \in \R^{N_g \times 1} </math> is the sensitivity vector containing the group sensitivities
+::::<math>{\overline{\overline{\mathbf{Cov}}}}^R_{X,X} \in \R^{N_g \times N_g}</math> is the covariance matrix containing the group covariances
+*The methodology is described in a related report<ref name="UncReport18">Valtavirta, V. ''"Nuclear data uncertainty propagation to Serpent generated group and time constants"'', Research report VTT-R-04681-18 [http://montecarlo.vtt.fi/download/VTT-R-04681-18_web.pdf (2018)].</ref>.
+*It requires setting the sensitivity calculation parameters. For more information, see the detailed description on [[Sensitivity calculations|sensitivity calculations]].
+=== set covlib ===
+ '''set covlib''' ''LIB<sub>1</sub>'' [ ''LIB<sub>2</sub>'' ''LIB<sub>3</sub>'' ... ]
+Sets plain ASCII multi-group covariance data file paths. Input values:
+{|
+| <tt>''LIB<sub>n</sub>''</tt>
+| : file paths to multi-group covariance data files in the plain ASCII format (ASCII or binary)
+|}
+The <u>syntax of the file</u> containing the covariance data is:
+::{| class="toccolours" style="text-align: left;"
+|-
+| ''NG'' ''E<sub>1</sub>'' ... ''E<sub>NG+1</sub>'' ''NM''
+|-
+| ''ZAI<sub>1,1</sub>'' ''MT<sub>1,1</sub>'' ''ZAI<sub>1,2</sub>'' ''MT<sub>1,2</sub>''
+|-
+| ''COV<sub>1,1,1</sub>'' ... ''COV<sub>1,NG,NG</sub>''
+|-
+|...
+|-
+| ''ZAI<sub>NM,1</sub>'' ''MT<sub>NM,1</sub>'' ''ZAI<sub>NM,2</sub>'' ''MT<sub>NM,2</sub>''
+|-
+| ''COV<sub>NM,1,1</sub>'' ... ''COV<sub>NM,NG,NG</sub>''
+|-
+|}
+where:
+{|
+| <tt>''NG''</tt>
+|: number of neutron energy groups
+|-
+| <tt>''E<sub>g</sub>''</tt>
+|: energy grid boundaries [in MeV]
+|-
+| <tt>''NM''</tt>
+|: number of covariance matrixes
+|-
+| <tt>''ZAI<sub>m,n</sub>'', ''MT<sub>m,n</sub>''</tt>
+|: 2 &times; nuclide ([[Definitions, units and constants#definitions|ZAI]])-reaction ([[ENDF reaction MT's and macroscopic reaction numbers#ENDF Reaction MT's|ENDF reaction MT]]) pairs defining the ''m''-th covariance matrix
+|-
+| <tt>''COV''<sub>m,g,g</sub>''</tt>
+|: ''NG'' &times; ''NG'' covariance data corresponding to the ''m''-th matrix
+|}
+<u>Notes:</u>
+*It enables first-order uncertainty propagation by collapsing the covariance data with the evaluated sensitivities.
+**It applies the <u>Sandwich rule</u>: <math>\mathbf{Cov}^R_X \approx ({\overline{\mathbf{S}}}^R_X)^T {\overline{\overline{\mathbf{Cov}}}}^R_{X,X} \overline{\mathbf{S}}^R_X</math>
+:: where: <math>{\overline{\mathbf{S}}}^R_X \in \R^{N_g \times 1} </math> is the sensitivity vector containing the group sensitivities
+::::<math>{\overline{\overline{\mathbf{Cov}}}}^R_{X,X} \in \R^{N_g \times N_g}</math> is the covariance matrix containing the group covariances
+*The methodology is described in a related report<ref name="UncReport18">Valtavirta, V. ''"Nuclear data uncertainty propagation to Serpent generated group and time constants"'', Research report VTT-R-04681-18 [http://montecarlo.vtt.fi/download/VTT-R-04681-18_web.pdf (2018)].</ref>.
+*It requires setting the sensitivity calculation parameters. For more information, see the detailed description on [[Sensitivity calculations|sensitivity calculations]].
 === set cpd ===
-  '''set cpd''' ''DEPTH'' [ ''N<sub>Z</sub> Z<sub>MIN</sub> Z<sub>MAX</sub>'' ]
+  '''set cpd''' ''DEPTH'' [ ''N<sub>Z</sub> Z<sub>MIN</sub> Z<sub>MAX</sub>'' ] [ ''LVL1'' ''LVL2'' ]
-Sets on the calculation of lattice-wise power distributions to output file [input]_core0.m on. Input values:
+Sets on the calculation of lattice-wise power distributions to output file <tt>[input]_core0.m</tt> on. Input values:
 {|
 | <tt>''DEPTH''</tt>
-| : The number of levels included. 1 is the first lattice calculated from universe 0 usually corresponding to assembly-wise distribution. 2 includes the first two levels usually corresponding to the assembly- and pin-wise distributions.
+| : The number of lattice-levels included.
 |-
 | <tt>''N<sub>Z</sub>''</tt>
-| : Number of equal sized axial bins into which the lattices are divided.
+| : Number of equal sized axial bins into which the lattices are divided (default value: 1)
 |-
 | <tt>''Z<sub>MIN</sub>''</tt>
-| : Minimum z-coordinate for the axial division.
+| : Minimum z-coordinate for the axial division [in cm] (default value: [[Definitions, units and constants#Constants|-INFTY]])
 |-
 | <tt>''Z<sub>MAX</sub>''</tt>
-| : Maximum z-coordinate for the axial division.
+| : Maximum z-coordinate for the axial division [in cm] (default value: [[Definitions, units and constants#Constants|INFTY]])
+|-
+| <tt>''LVL1''</tt>
+|: User-defined first level where to define the lattice-wise power distribution
 |-
+| <tt>''LVL2''</tt>
+|: User-defined second level where to define the lattice-wise power distribution
 |}
 <u>Notes:</u>
-* The default values for <tt>''N<sub>Z</sub>''</tt>, <tt>''Z<sub>MIN</sub>''</tt> and <tt>''Z<sub>MAX</sub>''</tt> are 1, -INFTY and INFTY, respectively.
+*The interpretation of the number of levels included is as follows:
+** <tt>''DEPTH''</tt> 1: includes the first level from the root universe, which "usually" corresponds to the assembly-wise distribution.
+** <tt>''DEPTH''</tt> 2:  includes the first two levels from the root universe, which "usually" corresponds to the assembly- and pin-wise distributions.
 === set cpop ===
   '''set cpop''' ''NPG'' ''NGEN'' ''NSKIP'' [ ''NSKIP2'' ]
-Sets parameters for simulated neutron population for corrector neutron transport solutions in burnup calculation. Typically used with the [[Stochastic Implicit Euler burnup scheme|SIE burnup scheme]]. Input values
+Sets parameters for simulated neutron population for corrector neutron transport solutions in burnup calculation. Typically used with the [[Stochastic Implicit Euler burnup scheme|SIE burnup scheme]]. Input values:
 {|
@@ Line 2,560: / Line 4,522: @@
 *Only source points from active cycles are included.
+*From version 2.2.1 and on, multi-step depletion source files can be generated <tt>[''FILE'']_[bu]</tt>, where "<tt>bu</tt>" is the burnup step. Otherwise, simply, <tt>[''FILE'']</tt>.
+=== set dataout ===
+ '''set dataout''' ''TABLE_LIST''
+Defines the tables included in the nuclear and material data file <tt>[input].out</tt>. Input values:
+{|
+| <tt>''TABLE_LIST''</tt>
+| : list of tables (default value: <tt>all/0</tt>)
+|}
+Possible list of tables:
+Possible key-words/variables are:
+::{| class="wikitable" style="text-align: left;"
+! Key-word
+! Table ID
+! Description
+|-
+| <tt>0, all</tt>
+|
+| include all available tables
+|-
+| <tt>1, nuc_summary</tt>
+| Table 1: Summary of nuclide data
+|
+|-
+| <tt>2, nuc_readec</tt>
+| Table 2: Reaction and decay data
+|
+|-
+| <tt>3, nuc_nfy</tt>
+| Table 3: Fission yield data
+| only in burnp mode
+|-
+| <tt>4, nuc_lostpath</tt>
+| Table 4: Lost transmutation paths
+| only in burnup mode
+|-
+| <tt>5, mat_summary</tt>
+| Table 1: Summary of material compositions
+|
+|-
+| <tt>8, allnuc</tt>
+|
+| (nuclide) Tables 1-4
+|-
+| <tt>9, allmat</tt>
+|
+| (material) Tables 1
+|-
+| <tt>-1</tt>
+|
+| omit the <tt>[input].out</tt> file
+|}
+<u>Notes:</u>
+*The output file data is divided into two sections: nuclear data (Tables 1-4) and material data (Table 1). Respectively, they include all the nuclides and their reactions as they are read from the nuclear data libraries, and the material data includes isotopic compositions and densities, as well as volumes and masses if available.
+*For more information, see detailed description of the [[Description of output files#Nuclide and material data output|nuclear and material data output]].
 === set dbrc ===
-  '''set dbrc''' ''E<sub>min</sub> E<sub>max</sub>'' [ ''NUC<sub>1</sub> NUC<sub>2</sub> '' ... ]
+  '''set dbrc''' ''E<sub>min</sub> E<sub>max</sub> NUC<sub>1</sub>'' [ ''NUC<sub>2</sub>'' ... ]
-Enables the use of doppler-broadening rejection correction (DBRC).
+Enables the use of doppler-broadening rejection correction (DBRC). Input values:
 {|
 | <tt>''E<sub>min</sub>''</tt>
-| : Minimum energy for DBRC
+| : Minimum energy for DBRC [in MeV]
 |-
 | <tt>''E<sub>max</sub>''</tt>
-| : Maximum energy for DBRC
+| : Maximum energy for DBRC [in MeV]
 |-
 | <tt>''NUC<sub>n</sub>''</tt>
-| : Nuclide identifiers for which to apply DBRC to, with 0 K cross section data, e.g. "92238.00c"
+| : zero-kelvin nuclide identifiers for which to apply DBRC (e.g. "92238.00c")
 |}
 <u>Notes:</u>
-*This description is not complete.
 *Use of DBRC requires 0 K cross section data.
 *See also Section 5.6 of [http://montecarlo.vtt.fi/download/Serpent_manual.pdf Serpent 1 User Manual].
+*This input could be given without any nuclides before version 2.1.32. Then DBRC was not used at all.
+=== set dd ===
+ '''set dd''' ''MODE'' [ ''X<sub>0</sub>'' ''Y<sub>0</sub>'' ''&alpha;<sub>0</sub>'' ]
+Invokes domain decomposition. Input values:
+{|
+| <tt>''MODE''</tt>
+| : decomposition mode (default value: 0)
+|-
+| <tt>''X<sub>0</sub>''</tt>
+| : x-coordinate of the domain decomposition origin (centre of the radial division, initial position of the angular division) [in cm] (default value: 0.0)
+|-
+| <tt>''Y<sub>0</sub>''</tt>
+| : y-coordinate of the domain decomposition origin (centre of the radial division, initial position of the angular division) [in cm] (default value: 0.0)
+|-
+| <tt>''&alpha;<sub>0</sub>''</tt>
+| : angular position of the domain decomposition origin [in degrees] (default value: 0.0)
+|}
+The possible modes are:
+::{| class="wikitable" style="text-align: left;"
+! Mode
+! Description
+! Notes
+|-
+| <tt>0</tt>
+| none
+|
+|-
+| <tt>1</tt>
+| depletion zone indexing-based decomposition
+| not recommended
+|-
+| <tt>2</tt>
+| sector-based decomposition
+| <tt>''X<sub>0</sub>''</tt>, <tt>''Y<sub>0</sub>''</tt> and <tt>''&alpha;<sub>0</sub>''</tt> are available
+|-
+| <tt>3</tt>
+| sector-based + central division decomposition
+| <tt>''X<sub>0</sub>''</tt>, <tt>''Y<sub>0</sub>''</tt> and <tt>''&alpha;<sub>0</sub>''</tt> are available, only applicable if MPI-tasks > 4
+|}
+<u>Notes:</u>
+*Domain decomposition works in MPI mode by separating burnable materials into different parallel tasks.
+*The number of domains is given by the number of MPI tasks.
+*Only burnable materials separated into depletion zones using the '''sep''' entry in the [[#div|div card]] are decomposed
+*Decomposed materials are plotted in domain-specific colors (unless the '''rgb''' entry in the [[#mat (material definition)|mat card]] is used)
+*The domain decomposition methodology is described in a related paper<ref name="dd">Garcia, M., Leppänen, J. and Sanchez-Espinoza, V. ''"A Collision-based Domain Decomposition scheme for large-scale depletion with the Serpent 2 Monte Carlo code."'' Ann. Nucl. Energy, [https://doi.org/10.1016/j.anucene.2020.108026 '''152''' (2021) 108026].</ref>.
+*For more information, see the detail description and practical example on the [[Domain decomposition|Domain decomposition]].
 === set declib ===
@@ Line 2,594: / Line 4,666: @@
 <u>Notes:</u>
-*Decay libraries are standard ENDF format files containing decay data.
+*Decay libraries are standard ENDF format<ref name="endf" /> files containing decay data.
 *If the file path contains special characters it is advised to enclose it within quotes.
-*A default directory path can be set by defining environment variable SERPENT_DATA. The code looks for decay data files in this path if not found at the absolute.
+*A default directory path can be set by defining environment variable <tt>SERPENT_DATA</tt>. The code looks for decay data files in this path if not found at the absolute.
+*From version 2.2.0 and on, a default decay data library directory file can be set by defining environment variable <tt>SERPENT_DECLIB</tt>.
+**This file will be used if no other path is given with '''set declib'''.
+=== set decomp ===
+ '''set decomp''' ''OPT'' [ ''ELEM<sub>1</sub>'' ''ELEM<sub>2</sub>'' ... ]
+Decomposes elemental entries in material cards into isotopes. Input values:
+{|
+| <tt>''OPT''</tt>
+| : option to include (1) or exclude (0) elements from decomposed list
+|-
+| <tt>''ELEM<sub>n</sub>''</tt>
+| : element names
+|}
+<u>Notes:</u>
+* Elemental entries are identifed from zero A in ZA.
+* The decomposition is based on built-in isotope fractions.
+* If the list is not provided, all elemental entries are decomposed.
 === set delnu ===
@@ Line 2,609: / Line 4,702: @@
 <u>Notes:</u>
+* Default values:
-*Delayed neutron emission is on by default in neutron criticality source and off by default in external source simulation mode.
+** Criticality source mode: the delayed neutron emission is "<tt>on</tt>"
+** External (static/dynamic) source mode: the delayed neutron emission is "<tt>off</tt>"
+*In time-dependent calculations, driven by the [[#set dynsrc|set dynsrc]] option, precursor based delayed neutron emission is included in the calculation
+** "<tt>off</tt>" at fission, but "<tt>on</tt>" at delayed nubar in total nubar.
 *See separate description of [[physics options in Serpent]] for differences to other codes.
+=== set depmtx ===
+ '''set depmtx''' ''MODE''
+Print burnup matrixes to <tt>[input]_depmtx_[mat]_[bu]_[ss].m</tt> file during burnup calculation, where "<tt>bu</tt>" is the burnup step and "<tt>ss</tt>" is the substep. Input values:
+{|
+| <tt>''MODE''</tt>
+| : option to switch on (1/yes) or off (0/no) the printing of burnup matrixes. The default value is "<tt>off</tt>"
+|}
+<u>Notes:</u>
+*With non-constant predictor, this option will stop the simulation up to version 2.1.31.
+*With multiple substeps, only the last one is kept after the simulation up to version 2.1.31.
+*The burnup matrix output is named <tt>depmtx_[mat][bu].m</tt> up to version 2.1.31.
 === set depout ===
-  '''set depout''' ''MODE''
+  '''set depout''' ''MODE'' [''STEP'']
-Controls which burnable material compositions are printed into the [input]_dep.m output file in case of divided materials. Input values:
+Controls which burnable material compositions are printed into the <tt>[input]_dep.m</tt> output file in case of divided materials. Input values:
 {|
 | <tt>''MODE''</tt>
-| : value indicating, which materials to output to the [input]_dep.m file (1 = only partials, 2 = only parents, 3 = both)
+| : value indicating, which materials to output to the <tt>[input]_dep.m</tt> file (1 = only partials, 2 = only parents, 3 = both). (default value: 2)
+|-
+|<tt>''STEP''</tt>
+| : value indicating the print-out interval of the <tt>[input]_dep.m</tt> file (0 = final step, 1 = all steps, 2 =none). (default value: 1)
 |}
 <u>Notes:</u>
 *Parent materials refer to materials defined by [[#mat (material definition)|mat cards]], and partials to depletion zones created automatically using the [[#div (divisor definition)|div card]].
-*Default is 2 (only parents).
+*Print-out interval step option 2, no <tt>[input]_dep.m</tt> generation, can be combined with post-processing re-depletion: [[Installing and running Serpent#Running Serpent|<tt>''-rdep''</tt>]] command line option.
+*Combined with the domain decomposition feature ([[#set dd|set dd]] option):
+**If the mode is different from 2, it generates multiple depletion files which are named adding <tt>_dd[mpiid]</tt> (domain decomposition identifier) to the standard file name.
+**Each of them contains the partial materials information of the given domain/MPI task.
+=== set deppara ===
+  '''set deppara''' ''PARAM_LIST''
+Defines the material- and isotopic-wise variables included in the depletion output file <tt>[input]_dep.m</tt>. Input values:
+{|
+| <tt>''PARAM_LIST''</tt>
+| : list of variables (default value: "<tt>all</tt>")
+|}
+Possible key-words/variables are:
+::{| class="wikitable" style="text-align: left;"
+! Key-word
+! Quantity
+! Output ID
+! Description
+|-
+| <tt>atom</tt>
+| atom density
+| <tt>ADENS</tt>
+| [in b<sup>-1</sup>cm<sup>-1</sup>]
+|-
+| <tt>mass</tt>
+| mass density
+| <tt>MDENS</tt>
+| [in g/cm<sup>3</sup>]
+|-
+| <tt>activity</tt>
+| activity
+| <tt>A</tt>
+| [in Bq]
+|-
+| <tt>dh</tt>
+| decay heat
+| <tt>H</tt>
+| [in W]
+|-
+| <tt>sf</tt>
+| spontaneous fission rate
+| <tt>SF</tt>
+| [in fissions/s]
+|-
+| <tt>gsrc</tt>
+| photon emission rate
+| <tt>GSRC</tt>
+| [in photons/s]
+|-
+| <tt>ingtox</tt>
+| ingestion toxicity
+| <tt>ING_TOX</tt>
+| [in Sv]
+|-
+| <tt>inhtox</tt>
+| inhalation toxicity
+| <tt>INH_TOX</tt>
+| [in Sv]
+|-
+| <tt>all</tt>
+|
+|
+| include full-set of variables
+|-
+| <tt>none</tt>
+|
+|
+| exclude full-set of variables
+|}
+<u>Notes:</u>
+*For more information, see detailed description of the [[Description of output files#Burnup calculation output|burnup calculation output]].
+=== set depstepbunorm ===
+ '''set depstepbunorm''' ''NORM''
+Sets the depletion step normalization in burnup calculations based on energy deposition. Input values:
+{|
+| <tt>''NORM''</tt>
+| : depletion step normalization mode based on energy deposition (1 = all materials, 2 = burnable materials)
+|}
+<u>Notes</u>
+* Default values (see [[#set edepmode|set edepmode]]):
+** For energy deposition modes 0/1:  the normalization includes only "<tt>burnable</tt>" materials - mode 2.
+** For energy deposition modes 2/3: the normalization includes "<tt>all materials</tt>" - mode 1.
 === set dfsol ===
@@ Line 2,632: / Line 4,836: @@
 {|
 | <tt>''MODE''</tt>
-| : boundary conditions for solver (1 = include net currents at boundary surfaces and corners, 2 = include only surface currents)
+| : boundary conditions for solver (1 = include net currents at boundary surfaces and corners, 2 = include only surface currents). (default value: 1)
 |-
 | <tt>''DC''</tt>
-| : type of diffusion coefficient used in the calculation (1 = INF_DIFFCOEF, 2 = TRC_DIFFCOEF)
+| : type of diffusion coefficient used in the calculation (1 = out-scattering 2 = transport correction). (default value: 1)
 |-
 | <tt>''NP''</tt>
-| : number of points for trapezoidal integration for homogeneous flux
+| : number of points for trapezoidal integration for homogeneous flux (default value: 100)
 |}
 <u>Notes:</u>
-*This input option is used to control how the deterministic diffusion flux solver used to obtain assembly discontinuity factors [[#set adf|(set adf)]] and pin power distributions [[#set ppw|(set ppw)]] is run.
+*This input option is used to control how the deterministic diffusion flux solver used to obtain assembly discontinuity factors ([[#set adf|set adf]]) and pin power distributions ([[#set ppw|set ppw]]) is run.
-*Default mode is 1 (include both surfaces and corners in solution).
+*The option syntax was revised in update 2.1.27 (<tt>''DC''</tt> option was added between <tt>''MODE''</tt> and <tt>''NP''</tt>).
-*Default diffusion coefficient is INF_DIFFCOEF, option 2 requires the [[#set trc|set trc]] option.
+*Deterministic diffusion flux solver use:
-*Default number of points for trapezoidal integration is 100.
+**Out-scattering approximation, <tt>INF_DIFFCOEF</tt> and <tt>INF_TRANSPXS</tt>.
-*See also separate description of the [[Diffusion flux solver|built-in diffusion flux solver]].
+**Transport correction, <tt>TRC_DIFFCOEF</tt> and <tt>TRC_TRANSPXS</tt>. It requires enabling the [[#set trc|set trc]] option.
-*The format was revised in update 2.1.27 (<tt>''DC''</tt> option was added between <tt>''MODE''</tt> and <tt>''NP''</tt>).
+*For more information, see a detailed description on the [[Diffusion flux solver|built-in diffusion flux solver]].
 === set dix ===
   '''set dix''' ''OPT''
-Sets double indexing for cross section energy grid look-up on or off:
+Sets double indexing for cross section energy grid look-up on or off. Input values:
 {|
@@ Line 2,659: / Line 4,863: @@
 <u>Notes:</u>
-*Double indexing<ref name="dix">Leppänen, J.
+*Double indexing is a method to speed-up the cross section look-up when energy grid unionization is not used for microscopic data.
-''"Two practical methods for unionized energy grid construction in continuous-energy Monte Carlo neutron transport calculation."'' Ann. Nucl. Energy [https://www.sciencedirect.com/science/article/pii/S0306454909001108 '''36''' (2009) 878-885].</ref> is a method to speed-up the cross section look-up when energy grid unionization is not used for microscopic data.
+*The method can be used only in optimization modes 1 and 3 (modes 2 and 4 are based on energy grid unionization), see [[#set_opti|set opti]] option.
-*The method can be used only in [[#set_opti|optimization modes]] 1 and 3 (modes 2 and 4 are based on energy grid unionization).
+* The methodology is described in related paper<ref name="dix">Leppänen, J.
+''"Two practical methods for unionized energy grid construction in continuous-energy Monte Carlo neutron transport calculation."'' Ann. Nucl. Energy [https://www.sciencedirect.com/science/article/pii/S0306454909001108 '''36''' (2009) 878-885].</ref>
-=== set dynsrc ===
+=== set dspec ===
-  '''set dynsrc''' ''PATH'' [ ''MODE'' ]
+  '''set dspec''' ''EGRID<sub>p</sub>'' ''EGRID<sub>n</sub>'