Output parameters

This page lists the output parameters in the main _res.m output file.

Homogenized group constants

Notes:

• Group constants are calculated by first homogenizing the geometry using a multi-group structure with H energy groups. The data is then collapsed into the final few-group structure with G groups using the infinite and B₁ leakage-corrected flux spectra.
• The B₁ calculation is off by default, and invoked by the set fum option.
• The intermediate multi-group structure is defined using option set micro.
• The few-group structure is defined using option set nfg.
• The universes in which the group constants are calculated are listed in option set gcu. The calculation is performed for root universe 0 by default, and can be switched off with "set gcu -1".

Group constants homogenized in infinite spectrum

Parameter	Size	Description
INF_MICRO_FLX	2H	Multi-group flux
INF_FLX	2G	Few-group flux
INF_KINF	2	Infinite multiplication factor

Reaction cross sections

Parameter	Size	Description
INF_TOT	2G	Total cross section
INF_CAPT	2G	Capture cross section
INF_FISS	2G	Fission cross section
INF_NSF	2G	Fission neutron production cross section
INF_KAPPA	2G	Average deposited fission energy (MeV)
INF_INVV	2G	Inverse neutron speed (s/cm)
INF_NUBAR	2G	Average neutron yield
INF_ABS	2G	Absorption cross section (capture + fission)
INF_REMXS	2G	Removal cross section (group-removal + absorption)
INF_RABSXS	2G	Reduced absorption cross section (total - scattering production)

Fission spectra

Parameter	Size	Description
INF_CHIT	2G	Fission spectrum (total)
INF_CHIP	2G	Fission spectrum (prompt neutrons)
INF_CHID	2G	Fission spectrum (delayed neutrons)

Scattering cross sections

Notes:

• Scattering production includes multiplying (n,2n), (n,3n), etc. reactions.

Parameter	Size	Description
INF_SCATT0	2G	Total P0 scattering cross section
INF_SCATT1	2G	Total P1 scattering cross section
INF_SCATT2	2G	Total P2 scattering cross section
INF_SCATT3	2G	Total P3 scattering cross section
INF_SCATT4	2G	Total P4 scattering cross section
INF_SCATT5	2G	Total P5 scattering cross section
INF_SCATT6	2G	Total P6 scattering cross section
INF_SCATT7	2G	Total P7 scattering cross section
INF_SCATTP0	2G	Total P0 scattering production cross section
INF_SCATTP1	2G	Total P1 scattering production cross section
INF_SCATTP2	2G	Total P2 scattering production cross section
INF_SCATTP3	2G	Total P3 scattering production cross section
INF_SCATTP4	2G	Total P4 scattering production cross section
INF_SCATTP5	2G	Total P5 scattering production cross section
INF_SCATTP6	2G	Total P6 scattering production cross section
INF_SCATTP7	2G	Total P7 scattering production cross section

Scattering matrices

Notes:

• Scattering production includes multiplying (n,2n), (n,3n), etc. reactions.
• The order of values (.coe) or value pairs (_res.m) is: $\Sigma_{1,1} \, \Sigma_{1,2} \, ... \, \Sigma_{2,1} \, \Sigma_{2,2} \, ...$ where $\Sigma_{g,g'}$ refers to scattering from group g to g'.
• The data in the _res.m file can be read into a G by G matrix with Matlab reshape-command, for example: reshape(INF_S0(idx,1:2:end), G, G).

Parameter	Size	Description
INF_S0	4G2	P0 scattering matrix
INF_S1	4G2	P1 scattering matrix
INF_S2	4G2	P2 scattering matrix
INF_S3	4G2	P3 scattering matrix
INF_S4	4G2	P4 scattering matrix
INF_S5	4G2	P5 scattering matrix
INF_S6	4G2	P6 scattering matrix
INF_S7	4G2	P7 scattering matrix
INF_SP0	4G2	P0 scattering production matrix
INF_SP1	4G2	P1 scattering production matrix
INF_SP2	4G2	P2 scattering production matrix
INF_SP3	4G2	P3 scattering production matrix
INF_SP4	4G2	P4 scattering production matrix
INF_SP5	4G2	P5 scattering production matrix
INF_SP6	4G2	P6 scattering production matrix
INF_SP7	4G2	P7 scattering production matrix

Diffusion parameters

Parameter	Size	Description
INF_TRANSPXS	2G	Transport cross section
INF_DIFFCOEF	2G	Diffusion coefficient

Poison cross sections

Notes:

• Printed only if poison cross section option is on (see set poi).

Parameter	Size	Description
INF_I135_YIELD	2G	Fission yield of I-135 (cumulative, includes all precursors)
INF_XE135_YIELD	2G	Fission yield of Xe-135
INF_PM149_YIELD	2G	Fission yield of Pm-149 (cumulative, includes all precursors)
INF_SM149_YIELD	2G	Fission yield of Sm-149
INF_I135_MICRO_ABS	2G	Microscopic absorption cross section of I-135
INF_XE135_MICRO_ABS	2G	Microscopic absorption cross section of Xe-135
INF_PM149_MICRO_ABS	2G	Microscopic absorption cross section of Pm-149
INF_SM149_MICRO_ABS	2G	Microscopic absorption cross section of Sm-149
INF_I135_MACRO_ABS	2G	Macroscopic absorption cross section of I-135
INF_XE135_MACRO_ABS	2G	Macroscopic absorption cross section of Xe-135
INF_PM149_MACRO_ABS	2G	Macroscopic absorption cross section of Pm-149
INF_SM149_MACRO_ABS	2G	Macroscopic absorption cross section of Sm-149

Group constants homogenized in B₁ leakage-corrected spectrum

Parameter	Size	Description
B1_MICRO_FLX	2H	Multi-group flux
B1_FLX	2G	Few-group flux
B1_KINF	2	Infinite multiplication factor
B1_KEFF	2	Effective multiplication factor
B1_B2	2	Critical buckling
B1_ERR	2	Absolute deviation of keff from unity

Reaction cross sections

Parameter	Size	Description
B1_TOT	2G	Total cross section
B1_CAPT	2G	Capture cross section
B1_FISS	2G	Fission cross section
B1_NSF	2G	Fission neutron production cross section
B1_KAPPA	2G	Average deposited fission energy (MeV)
B1_INVV	2G	Inverse neutron speed (s/cm)
B1_NUBAR	2G	Average neutron yield
B1_ABS	2G	Absorption cross section (capture + fission)
B1_REMXS	2G	Removal cross section (group-removal + absorption)
B1_RABSXS	2G	Reduced absorption cross section (total - scattering production)

Fission spectra

Parameter	Size	Description
B1_CHIT	2G	Fission spectrum (total)
B1_CHIP	2G	Fission spectrum (prompt neutrons)
B1_CHID	2G	Fission spectrum (delayed neutrons)

Scattering cross sections

Notes:

• Scattering production includes multiplying (n,2n), (n,3n), etc. reactions.

Parameter	Size	Description
B1_SCATT0	2G	Total P0 scattering cross section
B1_SCATT1	2G	Total P1 scattering cross section
B1_SCATT2	2G	Total P2 scattering cross section
B1_SCATT3	2G	Total P3 scattering cross section
B1_SCATT4	2G	Total P4 scattering cross section
B1_SCATT5	2G	Total P5 scattering cross section
B1_SCATT6	2G	Total P6 scattering cross section
B1_SCATT7	2G	Total P7 scattering cross section
B1_SCATTP0	2G	Total P0 scattering production cross section
B1_SCATTP1	2G	Total P1 scattering production cross section
B1_SCATTP2	2G	Total P2 scattering production cross section
B1_SCATTP3	2G	Total P3 scattering production cross section
B1_SCATTP4	2G	Total P4 scattering production cross section
B1_SCATTP5	2G	Total P5 scattering production cross section
B1_SCATTP6	2G	Total P6 scattering production cross section
B1_SCATTP7	2G	Total P7 scattering production cross section

Scattering matrices

Notes:

• Scattering production includes multiplying (n,2n), (n,3n), etc. reactions.
• The order of values (.coe) or value pairs (_res.m) is: $\Sigma_{1,1} \, \Sigma_{1,2} \, ... \, \Sigma_{2,1} \, \Sigma_{2,2} \, ...$ where $\Sigma_{g,g'}$ refers to scattering from group g to g'.
• The data in the _res.m file can be read into a G by G matrix with Matlab reshape-command, for example: reshape(B1_S0(idx,1:2:end), G, G).

Parameter	Size	Description
B1_S0	4G2	P0 scattering matrix
B1_S1	4G2	P1 scattering matrix
B1_S2	4G2	P2 scattering matrix
B1_S3	4G2	P3 scattering matrix
B1_S4	4G2	P4 scattering matrix
B1_S5	4G2	P5 scattering matrix
B1_S6	4G2	P6 scattering matrix
B1_S7	4G2	P7 scattering matrix
B1_SP0	4G2	P0 scattering production matrix
B1_SP1	4G2	P1 scattering production matrix
B1_SP2	4G2	P2 scattering production matrix
B1_SP3	4G2	P3 scattering production matrix
B1_SP4	4G2	P4 scattering production matrix
B1_SP5	4G2	P5 scattering production matrix
B1_SP6	4G2	P6 scattering production matrix
B1_SP7	4G2	P7 scattering production matrix

Diffusion parameters

Parameter	Size	Description
B1_TRANSPXS	2G	Transport cross section (calculated from diffusion coefficient)
B1_DIFFCOEF	2G	Diffusion coefficient

Poison cross sections

Notes:

• Printed only if poison cross section option is on (see set poi).

Parameter	Size	Description
B1_I135_YIELD	2G	Fission yield of I-135 (cumulative, includes all precursors)
B1_XE135_YIELD	2G	Fission yield of Xe-135
B1_PM149_YIELD	2G	Fission yield of Pm-149 (cumulative, includes all precursors)
B1_SM149_YIELD	2G	Fission yield of Sm-149
B1_I135_MICRO_ABS	2G	Microscopic absorption cross section of I-135
B1_XE135_MICRO_ABS	2G	Microscopic absorption cross section of Xe-135
B1_PM149_MICRO_ABS	2G	Microscopic absorption cross section of Pm-149
B1_SM149_MICRO_ABS	2G	Microscopic absorption cross section of Sm-149
B1_I135_MACRO_ABS	2G	Macroscopic absorption cross section of I-135
B1_XE135_MACRO_ABS	2G	Macroscopic absorption cross section of Xe-135
B1_PM149_MACRO_ABS	2G	Macroscopic absorption cross section of Pm-149
B1_SM149_MACRO_ABS	2G	Macroscopic absorption cross section of Sm-149

Delayed neutron data

Notes:

• The output always consists of 9 values: total, followed by precursor group-wise values. If the number of groups is 6, the last two values are zero.
• The actual number of groups depends on the cross section library used in the calculations. JEFF-3.1, JEFF.3.2 and later evaluations use 8 precursor groups, while earlier evaluations, as well as all ENDF/B and JENDL data is based on 6 groups.

Parameter	Size	Description
BETA_EFF	9	Effective delayed neutron fraction (currently calculated using the Meulekamp method)
LAMBDA	9	Decay constants

Assembly discontinuity factors

Notes:

• Calculation of assembly discontinuity factors requires the set adf option.
• The calculation currently supports only a limited number of surface types: infinite planes and square and hexagonal prisms.
• The order of surface data for square prisms is: $X_{\mathrm{W},1} \, X_{\mathrm{W},2} \, ... \, X_{\mathrm{S},1} \, X_{\mathrm{S},2} \, ... \, X_{\mathrm{E},1} \, X_{\mathrm{E},2} \, ... \, X_{\mathrm{N},1} \, X_{\mathrm{N},2} \, ...$

Parameter	Size	Description
BETA_EFF	9	Effective delayed neutron fraction (currently calculated using the Meulekamp method)
LAMBDA	9	Decay constants