Radioactive decay source, practical example
The radioactive decay source mode was implemented in Serpent 2.1.24 for the purpose of radiation transport calculations involving activated materials. The source term is determined by:
- Isotopic material compositions, either user-defined or obtained from a previous burnup / activation calculation
- Decay constants of radioactive nuclides read from ENDF format decay data file
- Emission spectra read from ENDF format decay data file
The radiation types in version 2.1.28 and earlier are limited to discrete photon emitting reactions. Work on continuum reactions, neutron emission and bremsstrahlung from beta decay is under way.
The radioactive decay source mode is most conveniently used with burnup or activation calculation, in which case the radioactive material compositions can be read from a binary restart file (see the set rfw and set rfr options).