Studies ofBi205andBi207by Proton-Transfer Reactions

The (${}_{}{}^3{}_{}{}^{}\mathrm{He},d$) and ($\alpha ,t$) reactions on ${}_{}{}^{204}{}_{}{}^{}\mathrm{Pb}$ and ${}_{}{}^{206}{}_{}{}^{}\mathrm{Pb}$ targets were investigated at bombarding energies of 44 and 45 MeV, respectively, in order to measure the fragmentation of the proton levels in ${}_{}{}^{205}{}_{}{}^{}\mathrm{Bi}$ and ${}_{}{}^{207}{}_{}{}^{}\mathrm{Bi}$. Orbital angular momentum transfers and spectroscopic factors were determined for those bound states containing more than 5-10% of the active single-proton strengths. The fragmentation of the low-lying $1h_{\frac{9}{2}}$ and $2f_{\frac{7}{2}}$ proton orbitals was found to be consistent with qualitative particle-core expectations in both ${}_{}{}^{205}{}_{}{}^{}\mathrm{Bi}$ and ${}_{}{}^{207}{}_{}{}^{}\mathrm{Bi}$, while the $1f_{\frac{5}{2}}$, $2p_{\frac{3}{2}}$, and $2p_{\frac{1}{2}}$ strengths were distributed among a large number of levels. A level-by-level comparison between cross sections for the ($\alpha ,t$) and (${}_{}{}^3{}_{}{}^{}\mathrm{He},d$) reactions identified two high-$l$ transitions to levels near 2.6 MeV in both isotopes. These observations suggest the presence of interactions between members of the ($3^{-},h_{\frac{9}{2}}$) multiplet and at least one single-particle level from the next major shell as predicted by calculations in the case of ${}_{}{}^{209}{}_{}{}^{}\mathrm{Bi}$.