Instability induced in a relativistic plasma flux by the excitation of surface waves

Abstract

An analysis is made of the instability of a plasma flux caused by the excitation of a new type of cylindrical surface electromagnetic waves at the interface between the flux and a stationary plasma. It is shown that, unlike the conventional case ε₁>0 and ε₂,<0, at the interface of a relativistic plasma beam there exist growing surface waves at frequencies corresponding to positive values of the permittivities on both sides of the discontinuity. For a given geometry and plasma density the critical parameter for the excitation of these waves is the wave radius of the flux.