A two-fluid model of the bifurcated current sheet

Abstract

Recent satellite observations show that current sheets in the space plasma environment are often characterized by bifurcated structures. The majority of the available models of the bifurcated current sheet in the literature are based upon equilibrium Vlasov-Maxwell kinetic theory. While in principle, kinetic models are more fundamental, investigations based on fluid theory can sometimes be advantageous. For instance, because of its inherent simplicity, fluid models of the current sheet can be used in the detailed nonlocal or global analysis of fluid stability. The present paper puts forth a two-fluid model of the bifurcated current sheet on the basis of the pseudo-potential method. According to the present model, double peaked current sheet is characterized by a transverse non-uniform flow and a profile of plasma density that has a plateau in the region between the current peaks. Further, the plasma pressure tensor associated with such a bifurcated current sheet is shown to be anisotropic and non-gyrotropic.