Study of charged particles emitted fromTe117compound nuclei. I. Argon-induced reactions

Abstract

The compound nucleus ${}_{}{}^{117}{}_{}{}^{}\mathrm{Te}$ was formed with ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ar}$ + ${}_{}{}^{77}{}_{}{}^{}\mathrm{Se}$ at 71- and 107-MeV excitation energies; the maximum relative angular momenta in the entrance channels are about $70\hslash$ and $110\hslash$. The deexcitation by protons, deuterons, tritons, $\alpha$ particles, and lithium was studied, measuring absolute cross sections, energy spectra, and angular distributions. The experimental results, especially the strong anisotropies of the $\alpha$-particle angular distributions and the dependence of the average energy on the emission angle, are discussed in terms of the statistical theory and the influence of very high angular momentum on the evaporation mechanism. The angular distributions of the elastic scattering have been measured simultaneously and are described by a strongly absorbing optical potential.