Thermonuclear fusion in dense stars: Electron screening, conductive cooling, and magnetic field effects

TL;DR

This paper investigates how plasma correlations, electron screening, and magnetic fields influence thermonuclear reactions in dense stellar environments like white dwarfs and neutron stars, providing improved models for ignition conditions.

Contribution

It introduces refined enhancement factors for reaction rates considering plasma correlations and magnetic fields, improving the understanding of ignition conditions in dense stellar objects.

Findings

Electron screening enhances thermonuclear reaction rates beyond linear mixing rule.

Magnetic fields significantly alter ignition curves in magnetar oceans.

Comparison with simplified models shows improved accuracy in predicting ignition conditions.

Abstract

We study the plasma correlation effects on nonresonant thermonuclear reactions of carbon and oxygen in the interiors of white dwarfs and liquid envelopes of neutron stars. We examine the effects of electron screening on thermodynamic enhancement of thermonuclear reactions in dense plasmas beyond the linear mixing rule. Using these improved enhancement factors, we calculate carbon and oxygen ignition curves in white dwarfs and neutron stars. The energy balance and ignition conditions in neutron star envelopes are evaluated, taking their detailed thermal structure into account. The result is compared to the simplified "one-zone model," which is routinely used in the literature. We also consider the effect of strong magnetic fields on the ignition curves in the ocean of magnetars.