Decays of 118In, 120In isomers to levels in 118Sn, 120Sn, and 122Sn.

Abstract

The nuclear excited states of $^{118}\mathrm{Sn}$, $^{120}\mathrm{Sn}$, and $^{122}\mathrm{Sn}$ were studied by means of the decays of 4.45-min $^{118}\mathrm{In}$ isomer, 46.2-sec and 47.3-sec $^{120}\mathrm{In}$ isomers, and 10.3-sec and 10.8-sec $^{122}\mathrm{In}$ isomers, respectively. The In activities were produced by the (n,p) reaction with 14-MeV neutrons on enriched samples of $^{118}\mathrm{Sn}$, $^{120}\mathrm{Sn}$, and $^{122}\mathrm{Sn}$. The \ensuremath{\gamma} rays, measured with a Ge(Li) detector, were incorporated into separate level schemes, each resulting from the decay of an individual In isomer. The experimental level schemes of $^{118}\mathrm{Sn}$, $^{120}\mathrm{Sn}$, and $^{122}\mathrm{Sn}$ were compared with level schemes calculated on the basis of a broken-pair model that includes up to two broken pairs in the 50<N<82 shell. This model is reasonably successful in explaining the experimental data for these nuclides.