Turbulence and transport in two-dimensional magnetized electron plasmas

TL;DR

This study uses nonlinear fluid simulations to explore turbulence and transport phenomena in two-dimensional magnetized electron plasmas, revealing how density gradients and electric fields influence energy cascades and electron transport.

Contribution

It introduces a new simulation code and demonstrates the impact of density gradients and electric fields on turbulence and transport in 2D electron plasmas, including formation of large-scale structures.

Findings

Energy cascades follow a Kolmogorov-like spectrum.

External electric fields significantly enhance electron transport.

Intermittent turbulence involves coexisting forward and inverse cascades.

Abstract

Electron plasmas confined by an external magnetic field exhibit variations in a two-dimensional plane orthogonal to the confining magnetic field. A nonlinear fluid simulation code to investigate the properties of 2-D electron plasma wave turbulence in a nonuniform magnetoplasma has been developed. It is found that the presence of the density gradient convection by mean electric fields considerably influence the characteristic nonlinear interaction processes, such as the energy cascades and the cross-field electron transport. The initial random turbulent state evolves towards an intermittent state where forward cascade of vorticity coexists with an inverse cascade of electric potential fluctuations. The latter lead to the formation of large scale entities in 2D electron plasmas and can be alternatively understood by seeking exact nonlinear coherent vortex solutions in the form of a dipolar-like configuration. The energy cascades are governed typically by the Kolmogorov-like $k^{-5/3}$ spectrum. In agreement with the experimental observations, we find that the electron transport is improved significantly by the application of an externally imposed electric field.