Two effects in nucleon-induced nonelastic cross sections based on the intranuclear cascade model

Abstract

Proton- and neutron-induced nonelastic cross sections for $^{12}\mathrm{C}, ^{27}\mathrm{Al}, ^{56}\mathrm{Fe}$, and $^{208}\mathrm{Pb}$ are investigated in the low-energy region from 100 MeV down to nearly 0 MeV based on a framework of the extended intranuclear cascade (INC) model. It is shown that the present INC model can reproduce the experimental data both for the proton- and for the neutron-induced nonelastic cross sections of a wide range of targets in a systematic way and that the crucial point is to include the suppressed transition probability of the excited particles due to the discrete level constraint. On the basis of the reliability of the INC calculation, we analyze two effects of the discrete level constraint and Coulomb repulsion separately for the proton and for the neutron injection cases, and we elucidate the domain of the target mass and the incident energy where two effects play important roles.