Shell effects and multi-chance fission in the sub-lead region

TL;DR

This paper uses a five-dimensional Langevin model to accurately simulate fission fragment distributions in mercury isotopes, highlighting the role of shell effects and multi-chance fission at various excitation energies.

Contribution

It introduces a comprehensive five-dimensional Langevin approach to model fission in heavy nuclei, emphasizing shell effects and multi-chance fission impacts.

Findings

Good agreement with experimental mass and energy distributions

Multi-chance fission effects are significant at low excitation energies

Kinetic energy distributions are sensitive to pre-scission neutron emission

Abstract

Within the recently developed five-dimensional Langevin approach for the description of fission of heavy nuclei, we have calculated the fission fragments mass and kinetic energy distributions for the fission of $^{180}$Hg and $^{190}$Hg formed in the reactions $^{36}$Ar +$^{144}$Sm $\Rightarrow$ $^{180}$Hg and $^{36}$Ar +$^{154}$Sm $\Rightarrow$ $^{190}$Hg at few excitation energies and found very good agreement between the calculated and experimental results. Special attention was paid to the accurate description of the dependence of shell effects on the excitation energy. It was shown that the effect of multi-chance fission on the mass distribution is noticeable only at small excitation energies. The kinetic energy distributions are more sensitive to pre-scission neutron emission.