70Ge(p,gamma)71As and 76Ge(p,n)76As cross sections for the astrophysical p process: sensitivity of the optical proton potential at low energies

TL;DR

This study measures the cross sections of specific proton-induced reactions on germanium isotopes within the astrophysical p process energy range, comparing results with models to improve understanding of low-energy proton interactions.

Contribution

It provides new experimental cross section data for 70Ge(p,gamma)71As and 76Ge(p,n)76As reactions, and discusses modifications to the optical proton potential at low energies.

Findings

Good agreement between experimental and theoretical S factors.

Data suggests need for modifications in optical potential models.

Results enhance understanding of proton interactions relevant to astrophysics.

Abstract

The cross sections of the 70Ge(p,gamma)71As and 76Ge(p,n)76As reactions have been measured with the activation method in the Gamow window for the astrophysical p process. The experiments were carried out at the Van de Graaff and cyclotron accelerators of ATOMKI. The cross sections have been derived by measuring the decay gamma-radiation of the reaction products. The results are compared to the predictions of Hauser-Feshbach statistical model calculations using the code NON-SMOKER. Good agreement between theoretical and experimental S factors is found. Based on the new data, modifications of the optical potential used for low-energy protons are discussed.