Employing ternary fission of $^{242}$Pu as a probe of very neutron rich matter

TL;DR

This study uses theoretical models of ternary fission in $^{242}$Pu to probe neutron-rich matter, refining understanding of cluster formation and nuclear matter properties at low densities and specific temperatures.

Contribution

It advances modeling of ternary fission yields by incorporating in-medium effects and provides detailed characterization of the source matter in neutron-rich conditions.

Findings

Optimal temperature of 1.29 MeV for yield modeling

Density of approximately 6.7 x 10^{-5} nucleons/fm^3 identified

Proton fraction Y_p = 0.035 consistent with experimental data

Abstract

Detailed assessments of the ability of recent theoretical approaches to modeling existing experimental data for ternary fission confirm earlier indications that the dominant mode of cluster formation in ternary fission is clusterization in very neutron rich, very low density, essentially chemically equilibrated, nucleonic matter. An extended study and comparison of these approaches applied to ternary fission yields in the thermal neutron induced reaction $^{241}$Pu($n_{\rm th}$,f) has been undertaken to refine the characterization of the source matter. The resonance gas approximation has been improved taking in-medium effects on the binding energies into account. A temperature of 1.29 MeV, density of $6.7 \times 10^{-5}$ nucleons/fm$^3$ and proton fraction $Y_p$ = 0.035 are found to provide a good representation of yields of the ternary emitted light particles and clusters. In particular, results for $Z= 1$ and 2 isotopes are presented. Isotopes with larger $Z$ are discussed, and the roles of medium and continuum effects, even at very low density are illustrated.