An Investigation of radiative proton-capture reactions in the Cd-In mass region

Abstract

The reaction network in the neutron-deficient part of the nuclear chart around $A \sim 100$ contains several nuclei of importance to astrophysical processes, such as the p-process. This work reports on the results from recent experimental studies of the radiative proton-capture reactions $^{112,114}\mathrm{Cd}(p,\gamma)^{113,115}\mathrm{In}$. Experimental cross sections for the reactions have been measured for proton beam energies residing inside the respective Gamow windows for each reaction, using isotopically enriched $^{112}\mathrm{Cd}$ and $^{114}\mathrm{Cd}$ targets. Two different techniques, the in-beam $\gamma$-ray spectroscopy and the activation method have been employed, with the latter considered necessary to account for the presence of low-lying isomers in $^{113}\mathrm{In}$ ($E_{\gamma} \approx 392$~keV, $t_{1/2} \approx 100$~min), and $^{115}\mathrm{In}$ ($E_{\gamma} \approx 336$~keV, $t_{1/2} \approx 4.5$~h). Following the measurement of the total reaction cross sections, the astrophysical S factors have been additionally deduced. The experimental results are compared with Hauser-Feshbach theoretical calculations carried out with the most recent version of TALYS. The results are discussed in terms of their significance to the various parameters entering the models.