Nuclear reaction models for systematic analysis of the fast neutron induced (n,p) reaction cross sections

Abstract

Taking into account compound, pre-equilibrium and direct reaction mechanisms, we suggest certain method for theoretical explanation of systematic regularity in the fast neutron induced (n,p) reaction cross sections. The statistical model, Griffin exciton model and PWBA are used. For systematical analysis of (n,p) reaction cross sections, simple and convenient formulae are deduced. It is shown that theoretical (n,p) cross sections are satisfactorily in agreement with experimental values for the 6, 8, 10, 13, 14.5, and 16MeV neutrons. Investigation of charged particle emission reactions induced by fast neutrons is important for both nuclear reactor technol- ogy and the understanding of nuclear reaction mechanisms. In particular, the systematic study of (n, p) reaction cross sections is necessary to estimate radiation damage due to hydrogen pro- duction, nuclear heating and transmutations in the structural materials of fission and fusion reactors. In addition, it is often necessary, in practice, to evaluate the neutron cross sections of the nuclides, for which no experimental data are available. Because of this, in last years we carried out the systematic analysis of known (n ,α ) and (n, p) cross sections and observed so-called isotopic effect in the wide energy interval of neutrons for the broad mass range of target nuclei (1-3). Also, some formulae for the systematic analysis of the fast neutron in- duced (n, p) reaction cross sections using the statistical model, exciton model and PWBA were obtained (4-6). In this paper the systematic analysis of known (n, p) cross sections for fast neutrons using the theoretical model formulae is described.