Entropy-driven excitation-energy sorting in superfluid fission dynamics

TL;DR

This paper investigates how nuclei in superfluid fission dynamics transfer excitation energy, revealing that energy flows to the colder fragment, explaining neutron emission patterns in fission.

Contribution

It introduces the concept of entropy-driven excitation-energy sorting in superfluid nuclei during fission, providing a new explanation for neutron emission behavior.

Findings

All excitation energy transfers to the colder fragment.

Explains increased neutron emission from heavy fission fragments.

Supports the constant-temperature behavior of superfluid nuclei.

Abstract

We study the consequences of the constant-temperature behaviour of nuclei in the superfluid regime for the exchange of excitation energy between two nuclei in thermal contact. This situation is realized at the scission configuration of fission at moderate excitation energies. It is shown that all available excitation energy is transferred to the colder fragment. This effect explains why an increase of excitation energy is translated into an increase of the number of emitted neutrons for the heavy fission fragments only. This observation remained unexplained up to now.