Wave propagation in rotating magnetised plasmas

TL;DR

This paper reviews how rotation affects wave propagation in magnetised plasmas, highlighting a new contribution to polarization rotation and exploring image rotation in plasma waves for diagnostic applications.

Contribution

It identifies a new rotational effect on polarization in magnetised plasmas and demonstrates image rotation in plasma waves, suggesting new diagnostic tools.

Findings

Rotation adds to Faraday rotation in plasmas.

Image rotation occurs in plasma waves with orbital angular momentum.

Potential for new plasma diagnostic techniques.

Abstract

Wave propagation properties in a medium are fundamentally affected when this medium is moving instead of at rest. In isotropic dielectric media rotation has two noteworthy contributions: one is a mechanically induced circular birefringence which materialises as a rotation of the polarisation, the other is image rotation which corresponds to a rotation of the transverse structure of a wave. Here we review the effect of rotation in a magnetised plasma. We first show that the mechanical effect of rotation on polarisation is in a magnetised plasma superimposed onto the classical Faraday rotation, and that failing to account for this new contribution could lead to errors in the interpretation of polarimetry data. We also demonstrate that image rotation is recovered in plasmas for a number of low-frequency magnetised plasma waves carrying orbital angular momentum, and that this phenomenon holds promise for the development of new rotation diagnostic tools in plasmas.