Experimental constraints on $\gamma$-ray strength function of $^{72}$Ga from $^{72}\mathrm{Ga(n,\gamma)^{72}Ga}$ capture data and reevaluation of Maxwellian-averaged cross sections of $^{71}$Ga

TL;DR

This study constrains the gamma-ray strength function of $^{72}$Ga using capture data and reevaluates the Maxwellian-averaged cross sections of $^{71}$Ga, providing improved nuclear data relevant for astrophysics and nuclear physics.

Contribution

It provides the first experimental constraint on the gamma-ray strength function of $^{72}$Ga and reevaluates the $^{71}$Ga cross sections using this data.

Findings

The gamma-ray strength function of $^{72}$Ga was extracted from capture data.

The Maxwellian-averaged cross section of $^{71}$Ga at 30 keV is 115.35 mb.

The reevaluated cross section is consistent with previous measurements.

Abstract

The $\gamma$-ray strength function of medium-mass neutron rich nuclei $^{72}$Ga has been extracted from the statistical Hauser-Feshbach analysis of the available capture data of $^{71}\mathrm{Ga}(n,\gamma){}^{72}\mathrm{Ga}$ over the 0.01 - 3 MeV energy range with the required nuclear level density (NLD) of the $^{72}$Ga constraint from the work of R. Santra et al.,[\href{https://doi.org/10.1103/PhysRevC.107.064611}{Physical Review C 107, 064611 (2023)}]. The Gogny D1M model for the E1 and M1 strength functions, including low-energy upbends of $^{72}$Ga nuclei, is experimentally constrained in the present work. Subsequently, the Maxwellian-averaged cross section(MACS) of $^{71}\mathrm{Ga}$ has been reevaluated based on the present $\gamma$-ray strength function. It is found that the present MACS value at \(kT = 30\) keV is 115.35$^{+11.92}_{-10.44}$ mb, which is consistent with previous work.