Neutron capture cross sections ofSn112,116,122,124

Abstract

The thermal cross sections and resonance integrals have been determined for radiative neutron capture by $^{112,116,122,124}\mathrm{Sn}$ leading to the ground and isomeric states of $^{113,123,125}\mathrm{Sn}$ and the isomeric state of $^{117}\mathrm{Sn}$. Using natural samples of Sn metal foils and high-resolution $\ensuremath{\gamma}$-ray spectroscopy, it was possible to determine a mutually consistent set of cross sections, particularly the small thermal cross sections leading to $11/{2}^{\ensuremath{-}}$ states. A detailed analysis of the $\ensuremath{\gamma}$-ray emissions from irradiated Sn samples enabled us to make new and more precise determinations of the energies and intensities of $\ensuremath{\gamma}$ rays emitted in the decays of 40-min $^{123m}\mathrm{Sn}$ and 9.5-min $^{125m}\mathrm{Sn}$ and corresponding adjustments to the energy levels of ${}^{123,125}$Sb. The present results support the recently adopted revised value for the branching ratio of the 255.1-keV $\ensuremath{\gamma}$ ray in the decay of $^{113}\mathrm{Sn}$. The presence of a $^{116m}\mathrm{In}$ impurity in our samples prompted a new determination of the energies and intensities of the $\ensuremath{\gamma}$ rays emitted in its decay and of the energy levels in $^{116}\mathrm{Sn}$.