Damping and dispersion of oscillating modes of a multicomponent ionic mixture in a magnetic field

TL;DR

This paper investigates the spectrum of oscillating modes in a multicomponent magnetized ionic mixture, revealing how Coulomb interactions and higher-order effects influence their damping and dispersion.

Contribution

It provides a detailed analysis of the damping and dispersion of oscillating modes considering long-range Coulomb interactions and Burnett terms in a magnetized ionic mixture.

Findings

Identification of four oscillating modes in the spectrum.

Quantitative evaluation of damping and dispersion effects.

Highlighting the importance of higher-order gradient terms.

Abstract

The collective-mode spectrum of a multicomponent magnetized ionic mixture for small wave number k is studied with the use of magnetohydrodynamics and formal kinetic theory. Apart from the usual thermal and diffusive modes, the spectrum contains a set of four oscillating modes. By evaluating the k^2 contributions to the eigenfrequencies, the damping and the dispersion of these oscillating modes are determined. The long-range nature of the Coulomb interactions is shown to imply that Burnett terms with higher-order gradients in the linear phenomenological laws have to be taken into account in order to obtain a full description of all damping and dispersion effects.