Nuclear fission chain reaction in cooling white dwarf stars

TL;DR

This paper investigates the possibility of nuclear fission chain reactions in crystallized actinide-rich solids within cooling white dwarf stars, proposing a novel mechanism for triggering Type Ia supernovae.

Contribution

It provides a detailed analysis of the fission chain reaction process in white dwarf solids and explores its implications as a new supernova ignition mechanism.

Findings

Fission chain reactions can reach high temperatures and densities in white dwarf solids.

This mechanism could ignite carbon burning, leading to supernova explosions.

Open physics questions remain about the detailed process and conditions.

Abstract

The first solids that form as a white dwarf (WD) starts to crystallize are expected to be greatly enriched in actinides. Previously [PRL 126, 1311010] we found that these solids might support a nuclear fission chain reaction that could ignite carbon burning and provide a new Type Ia supernova (SN Ia) mechanism involving an {\it isolated} WD. Here we explore this fission mechanism in more detail and calculate the final temperature and density after the chain reaction and discuss a number of open physics questions.