Nonlinear electron magnetohydrodynamic simulations of sausage-like instability of current channels

Abstract

The stability of current channels to fast electron magnetohydrodynamic modes is a topic of great interest in several frontier areas of plasma research, e.g., fast ignitor concept of laser fusion, fast Z pinches, plasma opening switches, current channels at the center of fast magnetic reconnection region, etc. This paper deals with a detailed fluid simulation study of linear and nonlinear aspects of the velocity shear modes in electron current channels in a two dimensional geometry. Simulation results clearly show the development of sausage-like structures (kink structures, which are intrinsically three-dimensional excitations, are ruled out in the present simulations) which grow linearly and eventually saturate by nonlinear effects. An analytic understanding of the nonlinear saturation mechanism is also provided.