On the conical refraction of hydromagnetic waves in plasma with anisotropic thermal pressure: General consideration

A phenomenon analogous to the conical refraction well known in crystalo-optics and crystaloacoustics is considered for the magnetohydrodynamical waves in a collisionless plasma with anisotropic thermal pressure. Imposing the most general condition for the existence of the phenomenon, the angle of the conical refraction is calculated, which appeared to be dependent on the ratio of the Alfvacute en velocity and sound speed measured in the perpendicular direction with respect to the external magnetic field. Feasible ways to experimentally demonstrate the phenomenon are discussed and a novelty brought about by the general consideration is outlined. copyright 1996 American Institute of Physics