Eigenmodes and eigenfunctions of high-power electromagnetic waves in inhomogeneous magnetized plasmas and their stability to stimulated Raman backscattering

Abstract

Eigenmodes and eigenfunctions of high-power electromagnetic waves in inhomogeneous magnetized plasmas are investigated. Considering the dielectric permittivity in the presence of an external magnetic field and relativistic nonlinearity and considering the inhomogeneity of the electron density in the linear and rippled structures, two nonlinear wave equations are obtained. In the linear regime, eigenmodes and eigenfunctions of the electric field for two-electron densities are obtained. In the nonlinear regime, results indicate that by increasing the external magnetic field, the amplitude of the electric field increases, which affects the dielectric permittivity. The conditions of the stimulated Raman backscattering and the equation of the space-charge potential are obtained. Results also indicate that in the presence of the external magnetic field, plasma inhomogeneity, and relativistic nonlinearity, the stimulated Raman backscattering becomes unstable.