Electron extraction mechanisms of a micro-ECR neutralizer

摘要

Three-dimensional particle simulations have been conducted to analyze the mechanisms of electron extraction through the orifices of a 4.2 GHz microwave discharge microneutralizer, using a xenon electron cyclotron resonance plasma. The dimensions of the neutralizer are 20 x 20 x 4 mm(3), and a ring-shaped microwave antenna and permanent magnets are employed for its discharges. The numerical model is composed of a particle-in-cell simulation with a Monte Carlo collision algorithm for charged particle motions, a finite-difference time-domain method for microwaves, and a finite element analysis for magnetostatic fields. The simulation results have shown that the electrostatic field inside the plasma source has a dominant effect on electron extraction. The extracted electrons move along the magnetic field line to the orifice entrances and the E x B drift at the orifice edge induces electron extraction. (C) 2016 The Japan Society of Applied Physics