Inertial energy dissipation in nuclear dynamics

TL;DR

This paper introduces a novel TDDFT+Langevin model that combines microscopic quantum dynamics with macroscopic stochastic analysis to better understand energy dissipation mechanisms in nuclear fission.

Contribution

The paper develops energy-dependent friction coefficients for fission nuclei using TDDFT and Langevin models, revealing a transition from viscous to inertial energy dissipation.

Findings

Energy-dependent friction coefficients match experimental fission yields.

Transition from viscous to inertial dissipation with increasing energy.

Model applicable to multiple actinide isotopes.

Abstract

We present the TDDFT+Langevin model that incorporates microscopic time-dependent density function theory (TDDFT) with macroscopic Langevin model. By extracting the energy-dependent dissipation effect from the TDDFT dynamics, quantum effects are introduced to the Langevin-type stochastic fission analysis. In this paper, by means of Skyrme nuclear effective interactions, the energy-dependent friction coefficients to be used in Langevin calculations are provided individually for 25 fission nuclei chosen from uranium, plutonium, curium, californium, and fermium isotopes. The validity of the energy-dependent friction coefficients are confirmed by comparing to the existing experimental fission fragment yields. In conclusion, depending on the energy, the transition of energy dissipation mechanism from conventional viscous energy dissipation to inertial energy dissipation is shown.