Variable density formation by intense microwave beams near the critical density

Modification of electron density of an inhomogeneous, unmagnetized plasma by the relativistic ponderomotive force of intense microwave beams near the critical density is studied. Using the Maxwell and fluid equations and taking into account the relativistic mass, relativistic ponderomotive force, linear inhomogeneity for electron temperature, and tangential inhomogeneity for electron density, the non‐linear electron density, non‐linear dielectric permittivity, and non‐linear wave equations are derived. Results show that positive and negative values of σ₁ and σ₂ (degree of inhomogeneity of the background electron density and electron temperature, respectively) parameters can affect the electric and magnetic field profiles. In addition, profiles of the non‐linear electron density indicate that by decreasing the σ₁ parameter, the amplitude of the peaks increases near the critical density. For positive values of the σ₂ parameter, by increasing this parameter the amplitude of the peaks increases, while for negative values of the σ₂ parameter, by decreasing this parameter the amplitude of the peaks increases.