Mode Transition of an Atmospheric Pressure Arc Plasma Jet Sustained by Pulsed DC Power

Abstract

An atmospheric pressure arc plasma jet sustained using pulsed DC power is studied by examining its appearance using a high-speed camera and measuring current and voltage waveforms at the powered electrode using current and high-voltage probes. Given the seemingly uniform in time visual appearance, the high-speed camera images show that the plasma jet undergoes some transition within each power cycle. Current and voltage waveform characteristics suggest that such a transition is most likely due to a glow-to-arc mode transition. The occurrence of this transition is controlled by the plasma physics rather than by the duty cycle of the pulsed power.