A new approach to barrier-top fission dynamics

TL;DR

This paper introduces a novel framework for modeling induced fission dynamics that bypasses traditional assumptions by using a discrete basis of configurations characterized by energy and shape, with dynamics driven by interaction matrix elements.

Contribution

The authors propose a new calculational approach for fission that uses configurations based on $K^$ quantum numbers and models fission as hopping between these configurations, avoiding the Bohr-Wheeler assumption.

Findings

Demonstrated configurations for a fictitious $^{32}$S decay.

Analyzed fission path geometry for $^{236}$U.

Showed limits include diffusion and quantized conductance.

Abstract

We proposed a calculational framework for describing induced fission that avoids the Bohr-Wheeler assumption of well-defined fission channels. The building blocks of our approach are configurations that form a discrete, orthogonal basis and can be characterized by both energy and shape. The dynamics is to be determined by interaction matrix elements between the states rather than by a Hill-Wheeler construction of a collective coordinate. Within our approach, several simple limits can be seen: diffusion; quantized conductance; and ordinary decay through channels. The specific proposal for the discrete basis is to use the $K^\pi$ quantum numbers of the axially symmetric Hartree-Fock approximation to generate the configurations. Fission paths would be determined by hopping from configuration to configuration via the residual interaction. We show as an example the configurations needed to describe a fictitious fission decay $^{32}{\rm S} \rightarrow ^{16}{\rm O} + ^{16}{\rm O}$. We also examine the geometry of the path for fission of $^{236}$U, measuring distances by the number of jumps needed to go to a new $K^\pi$ partition.