Coupled fission fragment angular momenta

TL;DR

This paper investigates the angular momentum coupling of fission fragments, demonstrating methods to generate spin ensembles and analyzing the distribution of their relative angles, reconciling conflicting models through scission geometry assumptions.

Contribution

It introduces sampling methods for fragment spins and explores how different scission geometries affect angular momentum distributions in nuclear fission.

Findings

Distribution of spin-spin opening angles can be modeled in various scenarios.

Different assumptions about scission geometry reproduce conflicting model results.

Sampling approaches effectively generate ensembles of coupled fragment spins.

Abstract

Nuclear fission produces fragments whose spins are coupled to the relative angular motion via angular momentum conservation. It is shown how ensembles of such spins can readily be obtained by either direct microcanonical sampling or by sampling of the associated normal modes of rotation. The resulting distribution of the spin-spin opening angle is illustrated in various three- and two- dimensional scenarios and it is demonstrated how recent mutually conflicting model calculations can be well reproduced with different assumptions about the scission geometry.