Kinetic intermittency in magnetized plasma turbulence

TL;DR

This paper investigates kinetic intermittency in magnetized plasma turbulence using gyrokinetic formalism, revealing how linear and nonlinear phase mixing influence electron and ion structures and their spatial intermittency.

Contribution

It introduces the first analysis of kinetic intermittency in plasma turbulence, linking spatial intermittency with linear phase mixing and Landau damping effects.

Findings

Electron structures are highly intermittent and dominated by linear phase mixing.

Ion structures are weakly intermittent with nonlinear phase mixing dominance.

Magnetic islands are regions of Landau damping correlated with electron intermittency.

Abstract

We employ magnetized plasma turbulence, described by a gyrokinetic formalism in an interval ranging from the end of the fluid scales to the electron gyroradius, to introduce the first study of kinetic intermittency, in which nonlinear structures formed directly in the distribution functions are analyzed by accounting for velocity space correlations generated by linear (Landau resonance) and nonlinear phase mixing. Electron structures are found to be strongly intermittent and dominated by linear phase mixing, while nonlinear phase mixing dominates the weakly intermittent ions. This is the first time spatial intermittency and linear phase mixing are shown to be self-consistently linked for the electrons and, as the magnetic field follows the intermittency of the electrons at small scales, explain why magnetic islands are places dominated by Landau damping in steady state turbulence.