10.1007/s11450-008-1002-2

Abstract

The spectra of prompt fission neutrons from the reaction 238 U(n, F ) for neutrons of energy in the range E n ≤ 20 MeV are interpreted within the statistical model. It is shown that exclusive spectra of prefission neutrons emitted in (n, xnf ) reactions play a decisive role in describing the observed promptfission-neutron spectra and determine the average energies of prompt-fission neutrons. The dependence of the effect of prefission neutrons on the fissility of a target nucleus is demonstrated for the reactions