Experimental study of $\alpha$-induced reactions on ${}^{113}$In for astrophysical $p$-process

Abstract

Neutron deficient nuclei from ${}^{74}$Se${-}^{196}$Hg are thought to be produced by $\gamma$-induced reactions ($\gamma$,n), ($\gamma$,p) and ($\gamma ,\alpha$) processes. The relatively high abundance of ${}^{113}$In odd A $p$-nuclei has inspired to study its production processes. As reaction with $\gamma$-beam is difficult to perform in the laboratory, $\gamma$-induced reaction rate is calculated from the inverse reaction data employing reciprocity theorem. Stacked foil activation method was used to measure the ${}^{113}$In($\alpha ,\gamma$) and ${}^{113}$In($\alpha$, n) reactions cross-section near the astrophysical energies. Theoretical statistical model calculations were performed with different nuclear input parameters and compared with the experimental results. An appropriate $\alpha$-optical potential has been identified from the ($\alpha ,\gamma$) and ($\alpha$, n) fitting, which provides the major source of uncertainty in the statistical model calculations. The other nuclear input parameters like level density, and $\gamma$-ray strength function were also constrained for theoretical calculations. ${}^{113}$In($\alpha ,\gamma$)${}^{117}$Sb and ${}^{117}$Sb($\alpha ,\gamma$)${}^{113}$In reaction rates were calculated using best-fitted input parameters.