Tolerance of pulsed discharges to contamination by gas phase particulates

In this paper, the authors theoretically investigate the consequence of contamination of pulsed gas discharges by gas phase particulates. This study is performed with a multi-dimensional continuum model for a glow discharge sustained in rare gases in which they specify a distribution of dust. The continuum model integrates the conservation and transport equations for excited states and ions, while driving the plasma with an external circuit. Electron impact rate coefficients are obtained from a lookup table in which they are catalogued as a function of E/N and dust density, as well as other pertinent parameters such as fractional ionization. These rate coefficients were obtained by separately parameterizing the Monte Carlo simulation described above. They find that variations in dust density of <10's% across the bore of the discharge tube (dust density ≅ 105 cm-3) are sufficient to cause constriction and arcing of the plasma. Wall generated contamination leads to arcing along the axis; volumetrically generated contamination leads to constriction along the walls. Tolerances of rare gas discharges against instabilities caused by contamination are presented