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arXiv · 2109.14714

Nuclear fission reaction simulations in compact stars

Alex Deibel·M. E. Caplan·C. J. Horowitz
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Abstract

Type-Ia supernovae (SN Ia) are powerful stellar explosions that provide important distance indicators in cosmology. Recently, we proposed a new SN Ia mechanism that involves a nuclear fission chain-reaction in an isolated white dwarf [PRL 126, 1311010]. Here we perform novel reaction network simulations of the actinide-rich first solids in a cooling white dwarf. The network includes neutron-capture and fission reactions on a range of U and Th isotopes with various possible values for U-235 enrichment. We find, for modest U-235 enrichments, neutron-capture on U-238 and Th-232 can breed additional fissile nuclei so that a significant fraction of all U and Th nuclei may fission during the chain-reaction. The resulting large energy release could ignite thermonuclear carbon burning and possibly trigger a SN Ia.

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Alex Deibel, M. E. Caplan, C. J. Horowitz. 2021-09-29. Nuclear fission reaction simulations in compact stars. https://doi.org/10.1103/physrevc.106.045803

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