A dynamical model calculation to reconcile the nuclear fission lifetime from different measurement techniques

TL;DR

This paper presents a dynamical model that reconciles differing measurements of nuclear fission lifetimes by incorporating shell effects and excitation energy impacts, aligning predictions with experimental data.

Contribution

The study introduces a dynamical model including shell effects to unify nuclear and atomic probe measurements of fission lifetimes across various reactions.

Findings

At low excitation energies, nuclear and atomic probes decouple, indicating longer fission times.

The model predicts a fission lifetime over 10^18 seconds for superheavy nucleus 302 120.

The predictions align with recent experimental observations.

Abstract

The pre-scission particle multiplicities suggest a lifetime of 10 20 s for the nuclear fission to occur which is in contrast to the fission lifetime 10 18 s as predicted by atomic probe. This long standing ambiguity, arising due to the orders of magnitude differences among the fission lifetime measured from the nuclear and atomic probes, has been addressed within a dynamical model which includes the contributions from the nuclear shell effects. We show that, at lower excitation energies, these two probes decouples as the fissioning system survives for a long time without any particle evaporation. We also consider a wide range of reactions to study the impact of the excitation energy of compound nucleus on the fission dynamics in general. Our model predicts the average fission life time of superheavy nucleus 302 120, to be more than 10 18 s which is in reasonable agreement with the recent experiments.