Turbulent multicomponent magnetopause: Analytical description and kinetic simulation of complex distributed current sheets

Abstract

We carry out particle-in-cell simulations of complex current sheets of the family of analytically found Vlasov--Maxwell equilibria that model a collisionless magnetopause and allow for arbitrary energy distributions and countercurrents of various particle component. We find that, depending on the parameters, i)~a weak small-scale bending-type instability is always present at the sharp low-density plasma boundary of such a magnetopause, and ii)~the development of a small-scale Weibel-type instability inside a magnetopause is either excluded or possible. Both cases are studied and compared for two variants of the particle energy distribution~ -- Maxwellian and Kappa. The long-term stability of the whole current sheet is observed either without or with saturated Weibel-type turbulence, which can be generated in a low-magnetized region between neighboring countercurrents. We point out the applicability of the developed model of distributed current sheets and the results of analysis of their small-scale instability for the description of physical phenomena in the magnetopauses of planets and late-type stars.