Two-dimensional simulation of cusp confinement of a plasma

Abstract

A two-dimensional particle-in-cell (PIC) simulation of a periodic 'picket fence' is described and used to study plasma behavior and confinement. A Lagrangian formulation which includes the invariance of the z-component of the generalized momentum is written as a time symmetric difference scheme in the electrostatic approximation. The results include the following features. The plasma settles into a steady state after a transient period. Positive charge peaks are formed in front of the 'fence' conductors. The potential develops a monotonically decreasing channel of the order of 0.5 Te/e in the cusp. The half-width of the leak in the cusp through which the ions escape is significantly smaller than the ion gyroradius.