Nonlinear scattering of upper hybrid laser radiation by electron Bernstein modes in a plasma

In this paper the authors investigate the nonlinear scattering of upper hybrid laser radiation by electron Bernstein modes in a homogeneous plasma. The kinetic-model approach has been used to obtain the nonlinear electron-density perturbation of magnetized electron Bernstein modes and nonlinear current density of unmagnetized scattered laser radiation. The threshold for the scattering is found to be rather low. It is found that the decay of upper hybrid laser radiation in a plane perpendicular to the magnetic field into electron Bernstein waves and scattered laser radiation in the ordinary mode is not possible. The analysis presented here for ${\mathrm{Co}}_2$-laser-produced plasma is valid marginally, whereas, for Nd:glass-laser-produced plasma, the validity of this investigation is described very well. The growth rate for the scattering by fundamental electron Bernstein modes in Nd:glass-laser(power density = ${10}^{12}$ W/${\mathrm{cm}}^2$)-produced plasma having a temperature of a few keV, is ≃ 6.0×${10}^{11}$ rad ${\sec }^{-1\mathrm{}}$.