Determination of Solar System R-Process Abundances using ENDF/B-VIII.0 and TENDL-2015 libraries

TL;DR

This study calculates solar system r-process abundances using ENDF/B-VIII.0 and TENDL-2015 nuclear data libraries, comparing results with existing data to enhance understanding of stellar nucleosynthesis.

Contribution

It provides the first comprehensive comparison of ENDF/B-VIII.0 and TENDL-2015 libraries for r-process abundance calculations in astrophysics.

Findings

Calculated MACS and reaction rates for key isotopes.

Identified data deficiencies in evaluated libraries.

Demonstrated potential for improved astrophysical models.

Abstract

Recent multi-messenger detection of the binary neutron star merger (GW170817) energized the astrophysical community and encouraged further research for determination of nuclear physics observables. Comprehensive studies of atomic nuclei in the cosmos provide an opportunity for investigating these astrophysical phenomena and acquiring complementary information on stellar nucleosynthesis processes that can be verified using the latest nuclear data. Evaluated Nuclear Data File (ENDF) libraries contain complete collections of reaction cross sections over the energy range relevant to astrophysics, fission yields and decay data. These data collections have been used worldwide in nuclear science, industry and national security applications. There is great interest in exploring the ENDF/B-VIII.0 and TALYS Evaluated Nuclear Data Library (TENDL-2015) for nuclear astrophysics purposes and comparing findings with the Karlsruhe Astrophysical Database of Nucleosynthesis in Stars (KADoNiS). The Maxwellian-averaged cross sections (MACS) and astrophysical reaction rates have been calculated using the ENDF/B-VIII.0 and TENDL-2015 evaluated data sets. The calculated cross sections were combined with the solar system abundances and fitted using the classical model of stellar nucleosynthesis. Astrophysical rapid- and slow-neutron capture, $r$- and $s$-process, respectively, abundances were obtained from present data and compared with available values. Further analysis of MACS reveals potential evaluated libraries data deficiencies and a strong need for new measurements. The current results demonstrate a large nuclear astrophysics potential of evaluated libraries and mutually beneficial relations between nuclear industry and research efforts.