On the Quasicollisionality of Plasmas with Small-Scale Electric Turbulence

TL;DR

This paper explores how small-scale electric turbulence in relativistic plasmas causes stochastic electron deflections, acting like effective collisions that significantly influence plasma radiative properties, including the Faraday effect.

Contribution

It introduces the concept of quasi-collisions caused by electric turbulence and analyzes their impact on plasma radiative transport, extending classical theories.

Findings

Electric turbulence induces pitch-angle diffusion similar to Coulomb collisions.

Quasi-collisions can significantly modify the Faraday effect in plasmas.

Small-scale electric fluctuations alter plasma radiative properties.

Abstract

Chaotic electromagnetic fields are common in many relativistic plasma environments, where they can be excited by instabilities on kinetic spatial scales. When strong electric fluctuations exist on sub-electron scales, they may lead to small-angle, stochastic deflections of the electrons' pitch-angles. Under certain conditions, this closely resembles the effect of Coulomb collisions in collisional plasmas. The electric pitch-angle diffusion coefficient acts as an effective collision -- or "quasi-collision" -- frequency. We show that quasi-collisions may radically alter the expected radiative transport properties of candidate plasmas. In particular, we consider the quasi-collisional generalization of the classical Faraday effect.