A consistent model for describing prompt fission neutrons
A theoretical model for a consistent description of prompt neutron emission for spontaneous and neutronand proton-induced fission over a wide range of energies is presented. Prompt fission neutron parameters are formed at the four main fission process stages: pre-equilibrium particle emission, neutron evaporation upon crossing the fission barrier, neutron evaporation upon descending from the saddle point to the scission point, and neutron emission from pairs of accelerated fragments. The Monte Carlo method is used to simulate the evolution of a nucleus undergoing fission down to the scission point. The parameters of an ensemble of sources after fragmentation are calculated using the scission point model and the multimodal fission model. Calculated neutron spectra and multiplicities are given for spontaneous 244–257Fm and 252Cf fission and 235U fission induced by thermal and 14.7 MeV neutrons.