BOUNDARY-CONDITIONS FOR A SIMULATION PLASMA IN A MAGNETIC-FIELD

Various methods of treating particles at the boundary walls in a magnetized simulation plasma are studied extensively. Especially, Lee and Okuda's 'reflection scheme' and the numerical instability caused by this scheme alone are investigated in detail. Methods (Method I, Method II, and the random reflection method), which eliminate the numerical instability, are proposed. They are simple and straightforward, and introduce neither a density gradient nor a surface current next to the walls. Lee and Okuda's complete method is stable by virtue of the introduction of a 'smoothing scheme,' and our methods provide an alternative. © 1979.