Trends in nuclear reaction cross sections (IV). Recalculated (n,p) cross sections for 14.5 MeV neutrons of nuclei in the range 6 ≦ Z ≦ 50

Abstract

In 1962 rough estimates were published of the absolute values of (n,p) cross sections of all stable isotopes of most of the elements. In this work we compute the relative (n,p) cross sections for isotopes of elements in the range 6 ≦ Z ≦ 50 using an equation, derived previously with the statistical model approach, in which only the level density parameter Q-value, pairing energy, effective Coulomb barrier and the energy of the incident neutron appear. The relative cross sections are used to compute absolute cross sections with the aid of an empirical equation. The latter cross sections agree with experiment in over 80% of the cases. The present calculations are compared with the predictions of the empirical equations of Levkovskii, and possible sources of shell effects in the observed cross sections are discussed.