Model expressions for refractive indices of electron waves in cold magnetoactive plasma

TL;DR

This paper derives simple analytical expressions for the refractive indices of all four electron wave modes in a magnetoactive plasma, applicable across various plasma conditions, enhancing understanding of wave propagation in such environments.

Contribution

It introduces universal operational expressions for electron wave refractive indices in magnetoactive plasma, independent of plasma to cyclotron frequency ratios.

Findings

Provides formulas for all four electron wave modes

Applicable across different plasma conditions

Simplifies analysis of wave propagation in magnetoactive plasma

Abstract

Despite the undoubted importance of having fairly simple analytical expressions for the refractive indices of wave modes in a magnetoactive plasma, such expressions are known only in some particular cases. For electron waves with frequencies much higher than the lower hybrid resonance frequency, such an expression is known only for whistler waves in a dense plasma when the electron plasma frequency significantly exceeds the electron cyclotron frequency. In this Letter, we propose simple operational expressions for the refractive indices of all four electron modes in a magnetoactive plasma, namely, the fast magnetosonic, also called whistler mode, the slow extraordinary mode, the ordinary mode, and the fast extraordinary mode. The form of these expressions does not depend on the value of the ratio of plasma frequency to cyclotron frequency.