Plasma clouds/jets transport across transverse magnetic barriers through three-dimensional particle-in-cell simulations

Thursday, 18 December 2014
Gabriel Voitcu1, Marius Echim1,2 and Joseph F Lemaire2,3, (1)Institute of Space Sciences, Bucharest, Romania, (2)Belgian Institute for Space Aeronomy, Brussels, Belgium, (3)Université Catholique de Louvain, Louvain-La-Neuve, Belgium
The study of plasma clouds/jets propagation across magnetic field configurations typical for the frontside magnetopause and the terrestrial magnetotail plays a key role for understanding the physics of the magnetosphere and its interaction with the solar wind. In this paper we use three-dimensional full-electromagnetic particle-in-cell simulations to investigate the interaction of localized plasma clouds with transverse magnetic field profiles typical for a tangential discontinuity. We consider a non-diamagnetic small Larmor radius plasma cloud streaming across a background non-uniform magnetic field that increases over few ion Larmor radii. Space and time variations of the plasma parameters and electromagnetic field are analyzed and discussed for different “strengths” of the transverse magnetic barrier. The numerical simulations reveal the formation of a polarization electric field that sustains the forward convection of the cloud across the discontinuity and illustrate the adiabatic breaking of the cloud as it is streaming into the right hand side of the discontinuity where the field is larger. The results obtained are compared with the theoretical model describing the impulsive penetration mechanism. When the initial bulk velocity of the plasma cloud is too small, the forward motion is stopped and an additional polarization electric field is created in the vicinity of the transition region that deflects the cloud along the discontinuity surface.