Nonlinear studies of fast electron current pulse propagation in a two dimensional inhomogeneous plasma

Abstract

The evolution of fast current and magnetic field pulse structures through an inhomogeneous plasma medium was reported in recent publications [ Yadav et al., Phys. Plasmas 15, 062308 (2008); Yadav et al., Phys. Plasmas 16, 040701 (2009) ]. The evolution characteristics have been investigated here in further detail. Following specific issues have been addressed; (i) characterization of the phenomena of trapping versus transmission of the current pulse structures through a high density plasma region, (ii) interaction of the current pulse with plasma density inhomogeneity at various incidence angles, and (iii) destabilization of sharp sheared current layers resulting from the interaction with an elongated plasma density inhomogeneity. It is also illustrated that the destabilization of the current pulse trapped in an elongated high density plasma region forms a novel stable coherent nonlinear pattern of alternating signed vortices arranged as beads along the density profile.