Prompt Gamma-ray Energy in the Frame of Prompt Neutron Emission Models

As output of the Point by Point model (taking into account the entire fission fragment range) and of the most probable fragmentation approach (working with one fragmentation and average values of model parameters) not only prompt neutron quantities are provided but also the prompt γ-ray energy as a function of fragment Eγ(A) and the total average prompt γ-ray energy . The almost linear behaviour of the total average with the prompt neutron multiplicity was observed experimentally in the incident neutron energy range where only the first fission chance is involved. This was parameterised as a function of Z and A of the fissioning nucleus. This parameterisation was validated by calculations in the frame of the most probable fragmentation approach. The results describe well the experimental data measured by J.FrŽhaut from thermal up to about 15 MeV incident energy for three fissioning systems 235U(n,f),237Np(n,f) and 232Th(n,f).The Point by Point model provides average prompt γ-ray energy as a function of the fragment pair in very good agreement with the existing experimental data of 252Cf(SF) and 233U(nth,f). The unique experimental data of prompt γ-ray energy as a function of fragment measured for 235U(nth,f) is very well described by the Point by Point model results obtained by using two methods of total excitation energy partition between complementary fission fragments.