Low-Lying Excited States inIn115andIn117

The low-lying levels in ${\mathrm{In}}^{115}$ and ${\mathrm{In}}^{117}$ have been studied by gamma-gamma and beta-gamma directional correlation and life-time measurements. The gamma-gamma directional correlation of the 1306-274-keV cascade in ${\mathrm{In}}^{117}$ was found to be $W\left(\theta \right)=1+(0.271\mathrm{}\pm 0.013)P_2\left(cos\theta \right)+(0.026\mathrm{}\pm 0.042)P_4\left(cos\theta \right)$. The measurement of the beta-gamma directional correlation between the beta transition from ${\mathrm{Cd}}^{115}$ to the 598-keV level in ${\mathrm{In}}^{115}$ and the following gamma transition of energy 261 keV gave a $P_2\mathrm{coefficient}{A}_2\mathrm{}\left(W\right)=-0.16\mathrm{}\pm 0.02$. Based on these measurements it is shown that the levels at 598 and 588 keV in ${\mathrm{In}}^{115}$ and ${\mathrm{In}}^{117}$, respectively, have spin and parity ${\frac{3}{2}}^{-}$. The half-life of the 747-keV level in ${\mathrm{In}}^{117}$ was found to be 4.9±0.2 nsec.