Study ofGe72with theGa71(He3, d)Ge72reaction

Abstract

The ${}_{}{}^{71}{}_{}{}^{}\mathrm{Ga}({}_{}{}^3{}_{}{}^{}\mathrm{He}, d){}_{}{}^{72}{}_{}{}^{}\mathrm{Ge}$ reaction has been studied at 25 MeV incident energy with a split-pole spectrometer. The over-all energy resolution was 18 keV. Sixty ${}_{}{}^{72}{}_{}{}^{}\mathrm{Ge}$ levels, 29 of which observed for the first time, were populated below 5.2 MeV excitation energy. Angular distributions were obtained from 5° to 63° and comparison with distorted-wave-Born-approximation calculations allowed parity assignment and spin limits for 44 levels. Spectroscopic factors are deduced for most of the observed transitions. The whole $2p-1f$ and a weak part of the $3s-2d-1g$ strengths are observed. An interesting result is the strong population of the first excited $0^{+}$ state at 0.690 MeV as compared to the ground state. We present a simple model which can account for this result. Possible $J^{\pi }=0^{+}$ levels in ${}_{}{}^{72}{}_{}{}^{}\mathrm{Ge}$ are found at 2.029 and 3.614 MeV.