Protons from Alpha-Induced Reactions

Abstract

The results of proton energy spectra measured at several angles from 30.5-Mev alpha particle induced reactions on ${\mathrm{Al}}^{27}$, ${\mathrm{V}}^{51}$, ${\mathrm{Co}}^{59}$, ${\mathrm{As}}^{75}$, ${\mathrm{Nb}}^{93}$, ${\mathrm{Rh}}^{103}$, ${\mathrm{In}}^{115}$, and ${\mathrm{Ta}}^{181}$ were analyzed using the statistical model. The analysis yielded the differential cross section $\frac{{d}^{2}\ensuremath{\sigma}}{d\ensuremath{\Omega}\mathrm{dE}}$ and the relative level density $\ensuremath{\omega}(E)$ of the residual nucleus as a function of proton and excitation energy of the residual nucleus. The nuclear temperature $\frac{1}{T}\ensuremath{\equiv}\frac{d(\mathrm{ln}\ensuremath{\omega})}{\mathrm{dE}}$ and the level density parameter $a$ of $\ensuremath{\omega}=C\mathrm{exp}[{(\mathrm{aE})}^{\frac{1}{2}}]$ were obtained. The energy and angular dependence of the spectra are adequately described by the statistical model at back angles, with the indication of the presence of a direct-reaction mechanism contribution at forward angles, which extends to high excitation energies.