$(h_{11/2},g_{7/2)9}$- neutron excitation in $^{92,94,96}$Sr
Résumé
Medium-spin structure of neutron rich nuclei 92Sr, 94Sr, and 96Sr have been studied in spontaneous fission of 248Cm. New spin and parity assignments done in this work differ significantly from those reported in other works. The 9- excitations, involving the (g7/2h11/2)9- maximum aligned configuration, were proposed in the three nuclei at 4930.2 keV, 4858.6 keV, and 3523.9 keV, respectively. Shell-model calculations, with the 78Ni core, support the proposed nature of the 9- excitations. The new data allow testing the single-particle energies in the region of 78Ni, and in particular, the position of the h11/2 orbital, which was not uniquely determined to date.