Intermittency in Hall-magnetohydrodynamics with a strong guide field

TL;DR

This paper investigates intermittency in Hall-magnetohydrodynamic turbulence with a strong guide field, revealing how the Hall effect influences fluctuation intermittency at small scales.

Contribution

It introduces a reduced model for compressible Hall-MHD turbulence with a guide field and analyzes intermittency variations across different scales and ion skin depths.

Findings

Magnetic field more intermittent than velocity in MHD limit

Hall effect reduces intermittency at scales below ion skin depth

Fluctuations become monofractal at small scales due to Hall effect

Abstract

We present a detailed study of intermittency in the velocity and magnetic field fluctuations of compressible Hall-magnetohydrodynamic turbulence with an external guide field. To solve the equations numerically, a reduced model valid when a strong guide field is present is used. Different values for the ion skin depth are considered in the simulations. The resulting data is analyzed computing field increments in several directions perpendicular to the guide field, and building structure functions and probability density functions. In the magnetohydrodynamic limit we recover the usual results with the magnetic field being more intermittent than the velocity field. In the presence of the Hall effect, field fluctuations at scales smaller than the ion skin depth show a substantial decrease in the level of intermittency, with close to monofractal scaling.