Quasineutral Particle Simulation of Magnetized Plasma Discharges: GeneralFormalism and Application to ECR Discharges

摘要

In quasineutral plasmas it is difficult and inefficient to calculate theelectrostatic field from Poisson's equation. We have developed a particle-in-cell/Monte Carlo (PIC/MC) simulation method for magnetized discharges, in which internal electric fields and sheath potentials are determined directly from the requirement of quasineutrality. Sheaths are treated as thin potential barriers, and the Bohm criterion for ion flux into the sheath is imposed as a boundary condition. Electron plasma oscillations do not appear in the model, and the Debye length is essentially set to zero. Thus time steps and spatial gridding can be chosen to represent the macroscopic time and space scales of interest, greatly enhancing numerical efficiency. The simulation technique correctly represents kinetic features such as Landau damping. We believe it is applicable generally to a wide variety of phenomena in plasmas that may be magnetized or unmagnetized, bounded or unbounded, collisional or collisionless.