Fission properties for r-process nuclei

TL;DR

This paper systematically studies fission barriers and lifetimes of super-heavy nuclei using Skyrme-Hartree-Fock models, comparing different parameterizations and exploring implications for neutron-rich isotopes in the r-process.

Contribution

It provides a comprehensive, self-consistent analysis of fission properties across the super-heavy element landscape, including diverse fission topologies and robustness checks.

Findings

Fission lifetimes vary significantly across super-heavy nuclei.

Different fission landscape topologies are identified, including symmetric, asymmetric, and triaxial fission.

Results suggest implications for the stability of neutron-rich isotopes in astrophysical r-process environments.

Abstract

We present a systematics of fission barriers and fission lifetimes for the whole landscape of super-heavy elements (SHE), i.e. nuclei with Z>100. The fission lifetimes are also compared with the alpha-decay half-lives. The survey is based on a self-consistent description in terms of the Skyrme-Hartree-Fock (SHF) approach. Results for various different SHF parameterizations are compared to explore the robustness of the predictions. The fission path is computed by quadrupole constrained SHF. The computation of fission lifetimes takes care of the crucial ingredients of the large-amplitude collective dynamics along the fission path, as self-consistent collective mass and proper quantum corrections. We discuss the different topologies of fission landscapes which occur in the realm of SHE (symmetric versus asymmetric fission, regions of triaxial fission, bi-modal fission, and the impact of asymmetric ground states). The explored region is extended deep into the regime of very neutron-rich isotopes as they are expected to be produced in the astrophysical r process.