Microscopic Calculation of Fission Product Yields for Odd-Mass Nuclei

TL;DR

This paper develops a method to accurately predict fission product yields for odd-mass nuclei using advanced nuclear mean-field theory, emphasizing the impact of neutron spin on fission fragment distributions.

Contribution

It introduces a novel approach combining Hartree-Fock-Bogoliubov theory with spin considerations to improve predictions of fission yields for odd-mass nuclei.

Findings

Fission fragment distributions vary significantly with neutron spin.

The proposed methodology enables rigorous predictions of charge and mass distributions.

Deformation properties of odd-mass uranium isotopes are effectively modeled.

Abstract

Fission data are essential inputs to reaction networks involved in nucleosynthesis simulations and nuclear forensics. In such applications as well as in the description of multi-chance fission, the characteristics of fission for odd-mass nuclei are just as important as those for even-even nuclei. The fission theories that aim at explicitly describing fission dynamics are typically based on some variant of the nuclear mean-field theory. In such cases, the treatment of systems with an odd number of particles is markedly more involved, both formally and computationally. In this article, we use the blocking prescription of the Hartree-Fock-Bogoliubov theory with Skyrme energy functionals to compute the deformation properties of odd-mass uranium isotopes. We show that the resulting fission fragment distributions depend quite significantly on the spin of the odd neutron. By direct calculation of the spin distribution of the fissioning nucleus, we propose a methodology to rigorously predict the charge and mass distributions in odd-mass nuclei.