Determination of the 74Ge(p, γ)75As reaction rates in p-process nucleosynthesis with in-beam γ spectroscopy

The Ge-74(p, gamma)As-75 reaction is believed to have a strong effect on the production of the lightest p-nucleus Se-74. The Ge-74(p, gamma)As-75 reaction cross sections were measured in the range of E-p = 2.5-4.3 MeV with an in-beam gamma spectroscopy method at the 3 MV tandem accelerator of the Institute of Nuclear Science and Technology, Sichuan University. The experimental results show good agreement with previous works, and extend the measurements to the widest energies to date combined with our latest work at the 1.7 MV tandem accelerator of China Institute of Atomic Energy. Our new cross sections are compared with theoretical predictions using the TALYS and EMPIRE nuclear reaction codes. The EMPIRE-EGSM calculation presents the best description of all the experimental data, and was used to derive the reaction rates. The present rates are significantly higher than the REACLIB compilation by a factor of up to 47% within the p-process relevant temperatures. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The Ge-74(p, gamma)As-75 reaction is important for the production of Se-74, a light p-nucleus. Experimental results of the reaction cross sections show good agreement with previous studies and extend measurements to wider energy ranges. Comparisons with theoretical predictions suggest that the EMPIRE-EGSM calculation provides the best description of the data.