Efficient method for estimation of fission fragment yields of r-process nuclei

Abstract

The knowledge of fission fragment yields of hundreds of nuclei inhabiting very neutron-rich regions of the nuclear landscape is crucial for the modeling of heavy-element nucleosynthesis. In this study, we propose a novel model for a fast calculation of fission fragment yields based on the concept of shell-stabilized prefragments calculated within realistic nuclear density functional theory. The new approach has been benchmarked against experimental data and advanced calculations reaffirming the dominant role of shell effects in the pre-scission region for forming fission yields.

Following nuclei through nucleosynthesis: A novel tracing technique

“…In such conditions, the specific nuclear abundances are expected to depend on the fission properties of many exotic neutron-rich nuclei [16,17,[43][44][45][46][47]. However, these fission properties effectively rely entirely on theory-based predictions, and a great deal of progress has been made to evaluate them, including from systematic, macroscopic-microscopic, and purely microscopic theoretical approaches (see, e.g., [48] and references therein for a recent review; also [16,17,37,[49][50][51][52]). In order to help inform existing and future efforts in the study of nuclear fission, we use our tracing framework to examine the various ways that different fission processes, namely spontaneous fission (sf ), β − -delayed fission (βdf ), and neutron-induced fission ((n, f )), can influence r-process nucleosynthesis in the ejecta of a neutron star merger.…”

Probing the fission properties of neutron-rich actinides with the astrophysical $r$ process

“…4 Fission yields from macroscopic-microscopic theory in the r process Very few theoretical approaches predicting fission yields have been applied to neutron-rich nuclei [11,28,29] and only a subset have considered all of the neutron-rich isotopes needed to perform a nucleosynthesis calculation. Therefore the majority of calculations in the literature make use of data-driven phenomenological models, such as the GEF treatment presented in the last section as well as the ABLA code (the precursor of GEF) and the Wahl systematics (see [8] for references and a literature overview of fission yield applications in the r process).…”