Definitions, units and constants
From Serpent Wiki
Definitions
- ZA defines the element and isotope as 1000 Z + A, where Z is the proton number and A is the mass number. For example, the ZA for U-235 is 92235.
- ZA.id defines nuclides in cross section data libraries. ZA identifies the nuclide and id is the library id (for example, 92235.09c).
- ZAI defines the element, isotope and isomeric state as 10000 Z + 10 A + I, where Z is the proton number, A is the mass number and I is the isomeric state. For example, the ZAI for U-235 is 922350 and the ZAI for Am-242m is 952421.
Units
Quantity | Unit | Notes |
---|---|---|
Distance | cm | |
Area | cm^{2} | |
Volume | cm^{3} | |
Time | s | depends on the case |
Energy | MeV | |
Microscopic cross section | b | barn = 10^{-24} cm^{2} |
Macroscopic cross section | 1/cm | |
Mass | g | |
Mass density | g/cm^{3} | |
Atomic density | 10^{24}/cm^{3} | ( = b^{-1}cm^{-1}) |
Power | W | |
Power density | kW/g | |
Particle flux | 1/cm^{2}s | |
Reaction rate | 1/cm^{3}s | reaction rate density |
Burnup | MWd/kgU | per total initial heavy metal |
Burn time | days |
Constants
Constant | Value | Units | Notes |
---|---|---|---|
INFTY | 10^{37} | N/A | Used to denote infinity |
ZERO | 10^{-37} | N/A | The smallest nonzero absolute value |