Proton hole states ofNb95,97,99

The ($d, {}_{}{}^3{}_{}{}^{}\mathrm{He}$) reactions on ${}_{}{}^{96,98,100}{}_{}{}^{}\mathrm{Mo}$ have been used at 40.7 MeV bombarding energy to populate proton hole states in the Nb isotopes. Ten groups of levels were observed in each nucleus and most of the expected strength in the $1g_{\frac{9}{2}}$, $2p_{\frac{1}{2}}$, $2p_{\frac{3}{2}}$, and $1f_{\frac{5}{2}}$ orbits was observed. Excitation energies and $l$ values were obtained for nine new excited levels in ${}_{}{}^{99}{}_{}{}^{}\mathrm{Nb}$. The $Q$ value for the ${}_{}{}^{100}{}_{}{}^{}\mathrm{Mo}(d,{}_{}{}^3{}_{}{}^{}\mathrm{He}){}_{}{}^{99}{}_{}{}^{}\mathrm{Nb}$ reaction was measured to be -5.639 ± 0.015 MeV, giving a ${}_{}{}^{99}{}_{}{}^{}\mathrm{Nb}$ mass excess of -82 342 ± 15 keV. A hole-core coupling model is used to predict the levels of the Nb isotopes, and fair agreement with experiment is obtained.