Simulations of 2D magnetic electron drift vortex mode turbulence in plasmas

TL;DR

This paper uses simulations to explore the turbulent behavior of 2D magnetic electron drift vortex modes in nonuniform plasmas, revealing anisotropic energy spectra and magnetic structures that influence electron transport.

Contribution

It introduces a detailed simulation study of nonlinear MEDV mode turbulence, highlighting the formation of streamer-like flows and anisotropic spectral characteristics.

Findings

Generation of streamer-like electron flows.

Steep anisotropic energy spectrum in turbulence.

Magnetic structures affect electron transport.

Abstract

Simulations are performed to investigate turbulent properties of nonlinearly interacting two-dimensional (2D) magnetic electron drift vortex (MEDV) modes in a nonuniform unmagnetized plasma. The relevant nonlinear equations governing the dynamics of the MEDV modes are the wave magnetic field and electron temperature perturbations in the presence of the equilibrium density and temperature gradients. The important nonlinearities come from the advection of the electron fluid velocity perturbation and the electron temperature, as well as from the nonlinear electron Lorentz force. Computer simulations of the governing equations for the nonlinear MEDV modes reveal the generation of streamer-like electron flows, such that the corresponding gradients in the direction of the inhomogeneities tend to flatten out. By contrast, the gradients in an orthogonal direction vary rapidly. Consequently, the inertial range energy spectrum in decaying MEDV mode turbulence exhibits a much steeper anisotropic spectral index. The magnetic structures in the MEDV mode turbulence produce nonthermal electron transport in our nonuniform plasma.