Impact of a minority relativistic electron tail interacting with a thermal plasma containing high-atomic-number impurities

TL;DR

This paper investigates how a small population of relativistic electrons can significantly influence the charge state distribution and radiative properties of a plasma with high-atomic-number impurities, even at low densities.

Contribution

It reveals the relativistic enhancement of collisional processes and its impact on plasma charge states and radiative losses, a novel insight into plasma impurity interactions.

Findings

Relativistic electrons dominate ion charge states at low temperatures.

Charge state distribution is significantly affected by relativistic cross section enhancements.

Radiative power loss rates are increased due to relativistic electron interactions.

Abstract

A minority relativistic electron component can arise in both laboratory and naturally-occurring plasmas. In the presence of high-atomic-number ion species, the ion charge state distribution at low bulk electron temperature can be dominated by relativistic electrons, even though their density is orders of magnitude lower. This is due to the relativistic enhancement of the collisional excitation and ionization cross sections. The resulting charge state effect can dramatically impact the radiative power loss rate and the related Bethe stopping power of relativistic electrons in a dilute plasma.