Scattering of 14.5-MeV Protons from the Even Isotopes of Germanium

Abstract

Protons from the 90-in. cyclotron at Lawrence Radiation Laboratory (LRL)-Livermore have been scattered from enriched targets of ${}_{}{}^{70,72,74,76}{}_{}{}^{}\mathrm{Ge}$, with an over-all energy resolution (FWHM) of 70 keV. The incident proton energy was approximately 14.5 MeV, and angular distributions were obtained from 20° to 150°, in 10° intervals. The elastic-scattering results were analyzed using the optical model. Angular distributions were obtained for inelastic proton groups from seven levels in ${}_{}{}^{70}{}_{}{}^{}\mathrm{Ge}$, nine levels in ${}_{}{}^{72}{}_{}{}^{}\mathrm{Ge}$, eleven levels in ${}_{}{}^{74}{}_{}{}^{}\mathrm{Ge}$, and ten levels in ${}_{}{}^{76}{}_{}{}^{}\mathrm{Ge}$—all below 3.5-MeV excitation. These included scattering to the quadrupole and octupole one-phonon vibrational levels and scattering to the $0^{+}$, $2^{+}$, $4^{+}$ two-quadrupole-phonon triplet. The data were analyzed using a coupled-channel computer code and a vibrational model of the nucleus. Strengths to excited states (${\beta }_I$) and spins and parities of levels were determined and are compared with Coulomb-excitation decay studies and with other scattering experiments.