Nonlinear longitudinal current, generated by two transversal electromagnetic waves in collisionless plasma

TL;DR

This paper derives a formula for nonlinear longitudinal electric current in collisionless plasma with any electronic gas degeneration, showing how two transversal electromagnetic waves induce a current along the wave vector.

Contribution

It introduces a new kinetic approach to calculate nonlinear plasma response to two electromagnetic waves, revealing the generation of a longitudinal current not present in linear analysis.

Findings

Derived a general formula for electric current in plasma with any electronic degeneration

Showed that nonlinear effects produce a longitudinal current along the wave vector

Compared the current's dependence on wave number and frequency graphically

Abstract

Classical plasma with any degree degeneration of electronic gas is considered. In plasma two external electromagnetic field are propagation. It is required to find the plasma response on these fields. From kinetic Vlasov equation for collisionless plasmas distribution function in square-law approximation on sizes of intensivities of two electric fields is received. The formula for calculation electric current at any temperature (any degree of degeneration electronic gas) is deduced. This formula contains an one-dimensional quadrature. It is shown, that the nonlinearity account leads to occurrence the longitudinal electric current directed along a wave vector. This longitudinal current is perpendicular to known tranversal classical current, received at the linear analysis. The case of small values of wave number is considered. Graphic comparison of dimensionless size of the current depending on wave number and frequency of oscillation of the electromagnetic fields is carry out.