Atmospheric Pressure Transient Micro Glow Discharge Driven by Burst Pulse Generator with Nonlinear Transmission Line

Abstract

Summary form only given. One of the features of microplasmas is that atmospheric pressure glow discharges (APGDs), which attract growing attention in a variety of plasma applications, are easily obtained. We reported the dc-powered microplasma in air between nozzle and mesh electrodes with miniature gas flow. Although the stable glow discharge was generated, the input power was the order of 0.1-0.5 W, which was rather low for high power applications. Transient glow discharges in atmospheric condition make the higher power operation possible. The transient glow discharge is obtained using the high-voltage pulse with extremely short duration that is shorter than characteristic time for the glow-to-arc transition. The pulse duration was typically less than 100 ns for the atmospheric microplasma. To obtain high voltage pulses having such a short duration, we utilized a nonlinear transmission line (NLTL) in the pulse generator. The NLTL is composed of lumped linear inductors and nonlinear capacitors of which capacitance decreases with increasing the applied voltage. In the NLTL, a voltage pulse with short duration propagates as a nonlinear wave and changes its initial shape into a solitary wave with shortening the pulse width and growing the amplitude. We applied input pulsed voltage with long duration, which developed into nonlinear pulse train with short duration of the order of 50 ns. The burst pulses with the peak voltage of 2.2 kV generate one stable micro transient glow discharge after another, owing to their short pulse width and the residual ions and electrons after the discharge. The glow discharge appears in the electrode system with needles or micro-spheres. The instantaneous electric power ranges up to 20 kW. However, the mean power is typically 10 W.