Modelling collisions in a relativistic plasma

TL;DR

This paper introduces a new fully relativistic collisional plasma model that simplifies fluid treatment and demonstrates how collisions dampen Langmuir waves, extending classical plasma physics into relativistic regimes.

Contribution

It presents a novel relativistic collisional plasma model that is linear and more tractable than traditional Fokker-Planck approaches, with derived fluid equations and analysis of wave damping.

Findings

Collision effects cause damping of Langmuir waves

The model is linear and suitable for fluid approximation

Extends classical plasma models into relativistic regimes

Abstract

Generalising the work of Lenard and Bernstein, we introduce a new, fully relativistic model to describe collisional plasmas. Like the Fokker-Planck operator, this equation represents velocity diffusion and conserves particle number. However, unlike the Fokker-Planck operator it is linear in the distribution function, and so more amenable to a fluid treatment. By taking moments, we derive a new fluid model, and demonstrate the damping effects of collisions on Langmuir waves.