i wrote a user source “source.f” to sample primary particle, i means the neutron energy is 9.441e-13 GeV, but the results show the energy of neutron is 1 GeV, why?
here is the input file:
ThermalCrossSection.inp (1.6 KB)
here is the source.f file:
source.f (9.4 KB)
the key code is:
PBEAM= SQRT (9.441d-13*9.441d-13+ TWOTWO * AM (IONID) )
here is the neutron current result cross a surface:
why the neutron energy is not the one i specialized?