Velocity fluctuations of fission fragments

TL;DR

This paper introduces velocity fluctuations of fission fragments as a novel observable to measure nuclear temperature and connect diffusion and friction coefficients in fission models, offering an alternative to spectral methods.

Contribution

It proposes using event-by-event velocity fluctuations of fission fragments to access nuclear temperature and relate diffusion and friction in Kramer-like models.

Findings

Velocity fluctuations provide an independent measure of nuclear temperature.

The approach links diffusion and friction coefficients in fission dynamics.

Neutron emission effects can be incorporated into the velocity distribution analysis.

Abstract

We propose event by event velocity fluctuations of nuclear fission fragments as an additional interesting observable that gives access to the nuclear temperature in an independent way from spectral measurements and relates the diffusion and friction coefficients for the relative fragment coordinate in Kramer-like models (in which some aspects of fission can be understood as the diffusion of a collective variable through a potential barrier). We point out that neutron emission by the heavy fragments can be treated in effective theory if corrections to the velocity distribution are needed.