Nuclear structure of Ge76 from inelastic neutron scattering measurements and shell model calculations

Abstract

The low-lying, low-spin levels of $^{76}\mathrm{Ge}$ were studied with the $(n,{n}^{\ensuremath{'}}\ensuremath{\gamma})$ reaction. Gamma-ray excitation function measurements were performed at incident neutron energies from 1.6 to 3.7 MeV, and $\ensuremath{\gamma}$-ray angular distributions were measured at neutron energies of 3.0 and 3.5 MeV. From these measurements, level spins, level lifetimes, $\ensuremath{\gamma}$-ray intensities, and multipole mixing ratios were determined. No evidence for a number of previously placed levels was found. Below 3.3 MeV, many new levels were identified, and the level scheme was re-evaluated. The $B(E2)$ values support low-lying band structure. The ${2}^{+}$ mixed-symmetry state has been identified for the first time. A comparison of the level characteristics with large-scale shell model calculations yielded excellent agreement.