Level structure of94,95,96Tcat high spins and shell-model calculations

Abstract

High-spin states in the ${}^{94,95,96}\mathrm{Tc}(N=51,$ 52, and 53) nuclei have been investigated using the ${}^{65}\mathrm{Cu}{+}^{36}\mathrm{S}$ reaction at a beam energy of 142 MeV. More than 60 new transitions have been identified and placed in their level schemes, which now extend up to spin $J\ensuremath{\approx}22\ensuremath{\Elzxh}$ and excitation energies ${E}_{x}\ensuremath{\approx}12$ MeV. Spherical shell-model calculations have been performed using different model spaces. A restricted model space, using ${}^{88}\mathrm{Sr}$ as the core and the $\ensuremath{\pi}{(p}_{1/2}{,g}_{9/2})$ $\ensuremath{\nu}{(d}_{5/2}{,s}_{1/2})$ valence orbitals, reproduces the experimental excitation energies up to $J\ensuremath{\approx}14\ensuremath{\Elzxh}.$ The higher-angular-momentum states are dominated by the excitation of a ${g}_{9/2}$ neutron across the $N=50$ magic core, as indicated by large-basis shell model calculations.