High-resolution Ge(Li) detectors have been used to observe $\gamma$-ray singles and coincidence spectra of 2.2-h ${}_{}{}^{127}{}_{}{}^{}\mathrm{Sn}$ (${\frac{11}{2}}^{-}$ ground state). Sources of mixed tin isotopes were produced by thermal-neutron fission of enriched ${}_{}{}^{235}{}_{}{}^{}\mathrm{U}$ and were chemically separated by solvent extraction and sulfide precipitation. A total of 162 $\gamma$ rays are attributed to the decay of ${}_{}{}^{127}{}_{}{}^{}\mathrm{Sn}_{}^g{}_{}{}^{}$, and 154 of these transitions have been placed in a ${}_{}{}^{127}{}_{}{}^{}\mathrm{Sb}$ level scheme involving 50 excited states. The $\beta$ feeding from ${\frac{11}{2}}^{-}{}_{}{}^{127}{}_{}{}^{}\mathrm{Sn}_{}^g{}_{}{}^{}$ to the ${\frac{7}{2}}^{+}$ ${}_{}{}^{127}{}_{}{}^{}\mathrm{Sb}$ ground state was determined to be (22 ± 8)% ($logft=8.0\mathrm{}$). Spin and parity assignments for ${}_{}{}^{127}{}_{}{}^{}\mathrm{Sb}$ levels have been made in many instances. An 11 ± 1-μsec ${\frac{15}{2}}^{-}$ isomeric level in ${}_{}{}^{127}{}_{}{}^{}\mathrm{Sb}$ at 1920 keV has been identified. The level structure of ${}_{}{}^{127}{}_{}{}^{}\mathrm{Sb}$ is interpreted in terms of the shell model and core-excitation considerations.

[RADIOACTIVITY ${}_{}{}^{127}{}_{}{}^{}\mathrm{Sn}_{}^g{}_{}{}^{}$ (from ${}_{}{}^{235}{}_{}{}^{}\mathrm{U}$ fission); measured $E_{\gamma }$, $I_{\gamma }$, $t_{\frac{1}{2}}\gamma$, $\gamma -\gamma$ coin; deduced $E_{\beta }$, $I_{\beta }$, $log\mathrm{ft}$. ${}_{}{}^{127}{}_{}{}^{}\mathrm{Sb}$ deduced levels, $J$, $\pi$. Enriched target; Ge(Li) detectors.]

• Received 19 June 1973

DOI:https://doi.org/10.1103/PhysRevC.9.310