Neutron capture $\gamma$-ray measurements have been performed upon enriched samples of ${}_{}{}^{122}{}_{}{}^{}\mathrm{Sn}$ and ${}_{}{}^{124}{}_{}{}^{}\mathrm{Sn}$ following resonance capture. The $\gamma$ rays, measured with a Ge(Li) detector, have been incorporated in level schemes for ${}_{}{}^{123}{}_{}{}^{}\mathrm{Sn}$ and ${}_{}{}^{125}{}_{}{}^{}\mathrm{Sn}$. New spin and parity assignments have been made for many of the levels. Three new levels have been found in ${}_{}{}^{125}{}_{}{}^{}\mathrm{Sn}$. Neutron separation energies for ${}_{}{}^{123}{}_{}{}^{}\mathrm{Sn}$ and ${}_{}{}^{125}{}_{}{}^{}\mathrm{Sn}$ were determined to be 5945.8 ± 1.5 and 5732.2 ± 1.5 keV, respectively. The level schemes have been compared with those of ${}_{}{}^{119}{}_{}{}^{}\mathrm{Sn}$ and ${}_{}{}^{121}{}_{}{}^{}\mathrm{Sn}$ to investigate systematic behavior.

NUCLEAR REACTIONS ${}_{}{}^{122}{}_{}{}^{}\mathrm{Sn}(n, \gamma )$, $E=0.1-20\mathrm{}$ keV, ${}_{}{}^{124}{}_{}{}^{}\mathrm{Sn}(n, \gamma )$, $E=0.05-11\mathrm{}$ keV; measured $E_{\gamma }$, $I_{\gamma }$. ${}_{}{}^{123,125}{}_{}{}^{}\mathrm{Sn}$ deduced levels, $J$, $\pi$, neutron separation energies. ${}_{}{}^{119,121,123,125}{}_{}{}^{}\mathrm{Sn}$ systematics. Enriched targets.

• Received 1 November 1976

DOI:https://doi.org/10.1103/PhysRevC.15.883