Thermal and atomic effects on coupled-channels heavy-ion fusion

TL;DR

This study investigates how thermal and atomic effects influence heavy-ion fusion probabilities in stellar environments using open quantum systems theory, revealing significant increases in fusion rates at high temperatures.

Contribution

It introduces a novel application of open quantum systems to model thermal effects on nuclear fusion, specifically analyzing excited state populations in stellar conditions.

Findings

Thermal effects increase fusion probability by 15.5% at 0.1 MeV

Fusion probability increases by 36.9% at 0.5 MeV

Laboratory tests could replicate these effects using excited state targets

Abstract

Stellar nuclear fusion reactions take place in a hot, dense plasma within stars. To account for the effect of these environments, the theory of open quantum systems is used to conduct pioneering studies of thermal and atomic effects on fusion probability at a broad range of temperatures and densities. Since low-lying excited states are more likely to be populated at stellar temperatures and increase nuclear plasma interaction rates, a 188Os nucleus was used as a target that interacts with an inert 16O projectile. Key results showed thermal effects yield an average increase in fusion probability of 15.5% and 36.9% for our test nuclei at temperatures of 0.1 and 0.5 MeV respectively, compared to calculations at zero temperature. Thermal effects could be tested in a laboratory using targets prepared in excited states as envisaged in facilities exploiting laser-nucleus interactions.