Influence of Angular Momentum on the Decay of theNi60Compound Nucleus

Abstract

In an experiment designed to study the effect of angular momentum on compound-nucleus reactions, the ${\mathrm{Ni}}^{60}$ compound nucleus has been produced at the same excitation energy by bombarding two different target nuclei: ${\mathrm{Fe}}^{56}$, with 20.7-MeV $\ensuremath{\alpha}$ particles, and ${\mathrm{Co}}^{59}$, with 16.3-MeV protons. When $\ensuremath{\alpha}$-particle and proton emission spectra from the ${\mathrm{Ni}}^{60}$ compound nucleus were separately measured at 10\ifmmode^\circ\else\textdegree\fi{} intervals, the angular distributions were found to be generally symmetric about 90\ifmmode^\circ\else\textdegree\fi{}. The $\ensuremath{\alpha}$-particle-induced reactions, however, showed more compound-nucleus anisotropy than the proton-induced reactions. The experimental cross sections are compared with the predictions of the semiclassical compound-nucleus theory of Ericson and Strutinski.