Microscopic calculation of fission product yields for odd-mass nuclei

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 multichance 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.

Automated summary

Fission data are crucial for nucleosynthesis simulations and nuclear forensics. The characteristics of fission for odd-mass nuclei, as well as even-even nuclei, are important in various applications. Fission theories that aim at describing fission dynamics are usually based on nuclear mean-field theories. In this article, we use the blocking prescription of the Hartree-Fock-Bogoliubov theory with Skyrme energy functionals to investigate odd-mass uranium isotopes. Our results show that the fission fragment distributions depend significantly on the spin of the odd neutron. We propose a methodology based on the calculation of the spin distribution to predict the charge and mass distributions in odd-mass nuclei.