Protons and deutrons from Ni58 bombarded by 14.8 MeV neutrons

Abstract

Using a counter telescope, energy spectra and angular distributions are measured for protons emitted from Ni58 at 14.8 MeV incident neutron energy. The angular distributions indicate for the direct interaction contribution l = 0 and l = 2 transitions to unresolved levels near the ground state of the residual Co58 nucleus. Transitions with l = 1 to states of higher excitation demonstrate the presence of odd parity levels. Below 6 MeV proton energy, the distributions are isotropic. Nuclear temperatures of 1.35±0.03 MeV and 0.50±0.03 MeV are found for the reactions (n, pγ) + (n, pn) and (n, np) respectively. The total cross section for proton emission is 830±70mb. Partial cross sections are: (n, pγ) + (n, pn) 430 mb compound nucleus, 60 mb direct interaction; (n, np) 340 mb.Deuteron emission is established, the total cross section for the (n, d) reaction being 25±6 mb. The angular distribution of the most prominent deuteron group suggests unresolved transitions to the 7/2− Co57 ground state and a new state at approximately 0.5 MeV. The presence of an l = 1 transition implies approximately 13% p-wave admixture in the Ni58 ground state configuration.