On the existence of small amplitude double layers in an electron–positron–ion plasma

Abstract

A theoretical model is presented to investigate the double layers, associated with the kinetic Alfvén waves, in a magnetized electron–positron–ion plasma with a small but finite value of β, and small-amplitude double layer solutions are obtained. The existence of small-amplitude double layers requires that the density of ions is appreciably larger than that of positrons at equilibrium. The properties of the double layers are determined by the ratio between the number densities of positrons and ions at equilibrium, the direction cosines defining the moving frame, as well as the electron to positron temperature ratio.