Magnetized microdischarge plasma generation at low pressure

摘要

A magnetized microdischarge plasma is generated at low pressure with planar electrodes and a non-uniform magnetic field configuration causing closed E×B electron drift. Stable generation with a 1 mm electrode gap has been achieved in 0.5-55 Torr of argon. The breakdown voltage curve is found to have two local minima, the lower of which is believed to be caused by strong electron magnetization, as supported by simple Monte Carlo simulations. The current-voltage curves show strong variations between operation at 10 Torr and lower pressures. The plasma confinement, as inferred from the luminous emission of the annular-shape discharge, appears to be stronger at low pressures. Optical emission is used to infer electron excitation temperatures, which are estimated to be about 1 eV.