Radioactivity ofIn117andSb117

Abstract

The $p_{\frac{1}{2}}$ isomeric level of ${\mathrm{In}}^{117}$ decays with a 1.9-hr half-life 49 percent by a 1.777-Mev ${\beta }^{-}$ to the $s_{\frac{1}{2}}$ ground state of ${\mathrm{Sn}}^{117}$, 23 percent by a 1.616-Mev ${\beta }^{-}$ to the 0.161-Mev $d_{\frac{3}{2}}$ level of ${\mathrm{Sn}}^{117}$, and 28 percent by an $M4\mathrm{}$ 0.311-Mev $\gamma$ to the $g_{\frac{9}{2}}$ ground state of ${\mathrm{In}}^{117}$. The latter decays with a 1.1-hr half-life by a 0.740-Mev ${\beta }^{-}$ to the $g_{\frac{7}{2}}$ level of ${\mathrm{Sn}}^{117}$ which is de-excited by a 0.565-Mev $\gamma$ and a 0.161-Mev $\gamma$ in cascade. There is no cross-over $\gamma$ (<1 percent). Less than 10 percent of the 3.0-hr ${\mathrm{Cd}}^{117}$ decays to the 1.9-hr level. Less than 1 percent of the 1.1-hr ground state populates the 14-day ${\mathrm{Sn}}^{117m}$. The 2.8-hr ${\mathrm{Sb}}^{117}$ decays to the 0.161-Mev level of ${\mathrm{Sn}}^{117}$ by a 0.61-Mev ${\beta }^{+}(\frac{{\beta }^{+}}{\epsilon }=0.026)$ but does not decay to the 0.323- or 0.726-Mev levels (<0.5 percent).