Dissipation of Nonlinear Alfven Waves with Current Sheets in Relativistic Plasmas

TL;DR

This study uses 2.5D Particle-in-Cell simulations to explore how nonlinear Alfven waves interact with current sheets in relativistic plasmas, revealing enhanced dissipation and electron heating mechanisms relevant to astrophysical turbulence.

Contribution

It demonstrates the combined effects of nonlinear Alfven waves and current sheets on energy dissipation and electron heating in relativistic plasmas, a novel insight into plasma turbulence.

Findings

Alfven waves cause current sheet bending and kink instability.

Electron populations form a double Maxwellian distribution.

Enhanced dissipation linked to wave-current sheet interactions.

Abstract

We present results from 2.5-dimensional Particle-in-Cell simulations of the interaction of nonlinear Alfven waves with thin current sheets in relativistic plasmas. We find that the Alfven waves cause the current sheet to bend and kink and increase its dissipation. The electrons are eventually heated to form a double Maxwellian, with the hotter Maxwellian caused by the current sheet dissipation and cooler Maxwellian caused by the Alfven turbulence cascade. These results may have important implications for the kinetic dissipation of MHD turbulence in which both nonlinear Alfven waves and current sheets are present, such as turbulence in accretion flows driven by the saturated magnetorotational instability (MRI).