Influence of perturbations in a magnetoplasma on the propagation of quasioptical wave beams

We analyzed features of the influence of perturbations in an anisotropic medium on the propagation of quasioptical wave beams. The solutions of the quasioptical equation in the nonaberrational approximation are found, which describe the evolution of the wave-beam width. It is shown that the influence of perturbations in an anisotropic medium differs qualitatively from the influence of the perturbations in an isotropic medium. Examples are presented of numerical calculations of the wave beam profiles in model media corresponding to the cases of density and magnetic field perturbations in the magnetoplasma confined in toroidal devices (tokamaks and stellarators).