Microscopic description of fission in neutron-rich plutonium isotopes with the Gogny-D1M energy density functional

TL;DR

This study employs the Gogny-D1M energy density functional within a microscopic framework to analyze fission properties, half-lives, and fragment characteristics of neutron-rich plutonium isotopes, comparing results with experimental data and exploring pairing effects.

Contribution

It introduces a systematic microscopic analysis of plutonium isotope fission using Gogny-D1M, including pairing modifications and validation against other nuclei.

Findings

Gogny-D1M reproduces fission trends across isotopes.

Pairing strength variations significantly affect predicted half-lives.

The framework effectively describes fission fragment properties and competition with alpha decay.

Abstract

The most recent parametrization D1M of the Gogny energy density functional is used to describe fission in the isotopes $^{232-280}$ Pu. We resort to the methodology introduced in our previous studies [Phys. Rev. C \textbf{88}, 054325 (2013) and Phys. Rev. C \textbf {89}, 054310 (2014)] to compute the fission paths, collective masses and zero point quantum corrections within the Hartree-Fock-Bogoliubov framework. The systematics of the spontaneous fission half-lives t$_{SF}$, masses and charges of the fragments in Plutonium isotopes is analyzed and compared with available experimental data. We also pay attention to isomeric states, the deformation properties of the fragments as well as to the competition between the spontaneous fission and $\alpha$-decay modes. The impact of pairing correlations on the predicted t$_{SF}$ values is demonstrated with the help of calculations for $^{232-280}$Pu in which the pairing strengths of the Gogny-D1M energy density functional are modified by 5 $\%$ and 10 $\%$, respectively. We further validate the use of the D1M parametrization through the discussion of the half-lives in $^{242-262}$Fm. Our calculations corroborate that, though the uncertainties in the absolute values of physical observables are large, the Gogny-D1M Hartree-Fock-Bogoliubov framework still reproduces the trends with mass and/or neutron numbers and therefore represents a reasonable starting point to describe fission in heavy nuclear systems from a microscopic point of view.