Dielectric permittivity of electron plasma with laser beat waves

TL;DR

This paper investigates how laser beat waves influence the dielectric permittivity of a rarefied electron plasma, deriving analytical expressions considering initial velocity spreads and anisotropic effects.

Contribution

It introduces a kinetic framework that accounts for velocity spread and anisotropy in plasma dielectric permittivity under laser beat wave interaction, providing new analytical formulas.

Findings

Derived anisotropic dielectric permittivity tensor for plasma with laser beat waves.

Obtained analytical expressions for longitudinal and transverse dielectric permittivity components.

Connected conductivity tensor with dielectric permittivity in a nonequilibrium plasma context.

Abstract

Within the framework of the kinetic method, the process of interaction of a rarefied electron plasma with laser beat waves is investigated taking into account the initial spread in the velocities of plasma particles. Using the expression for the spectral distribution function of plasma particles in the presence of laser beat waves, an anisotropic tensor of the plasma dielectric permittivity is obtained. In this case, an expression for the nonequilibrium current density induced by the perturbed field and the constitutive equation connecting the conductivity tensor with the dielectric permittivity are determined. Assuming that in equilibrium the particle distribution function has the form of the Maxwellian distribution function, the dielectric tensor is diagonalized. Analytical expressions are obtained for the longitudinal and transverse components of the dielectric permittivity.