Strong collisionless damping of the low-velocity branch of electromagnetic wave in plasmas with Maxwellian-like electron velocity distribution function

TL;DR

This paper derives an analytical expression for the collisionless damping of low-velocity electromagnetic waves in plasmas with Maxwellian-like electron distributions, highlighting the impact of small deviations in the distribution tail.

Contribution

It introduces a novel analytical approach by approximating the Maxwellian distribution with a rational polynomial, enabling precise calculation of the damping effect.

Findings

Strong collisionless damping occurs at small deviations from Maxwellian distribution.

The damping effect is significant in regions of large electron density.

Differences in the distribution tail influence wave damping despite low electron density there.

Abstract

After approximate replacing of Maxwellian distribution exponent with the rational polynomial fraction we have obtained precise analytical expression for and calculated the principal value of logarithmically divergent integral in the electron wave dispersion equation. At the same time our calculations have shown the presence of strong collisionless damping of the electromagnetic low-velocity (electron) wave in plasmas with Maxwellian-like electron velocity distribution function at some small, of the order of several per cents, differences from Maxwellian distribution in the main region of large electron densities, however due to the differences in the distribution tail, where electron density itself is negligibly small.