Atypical Self-Action of Axisymmetric Magnetoacoustic Beams Containing Shock Fronts

Quasi-planar perturbations in a plasma are described by the system of ideal magnetohydrodynamic equations in the presence of the straight constant equilibrium magnetic field. Axisymmetric magnetosonic beams directed along the magnetic field reveal especial diffraction. Diffraction is more manifested as compared to a flow without a magnetic field, and it may be atypical in dependence on the ratio of the sound and the Alfv & eacute;n speeds. Some heating-cooling function responsible for loss/gain of energy is included which may make a flow acoustically active. Unusual diffraction and the impact of the heating-cooling function bring variety in the scenario of nonlinear dynamics of perturbations as well. Self-refraction and thermal self-action of beams containing shock fronts are analytically described.