Mode Transition of the Positive Needle-to-Plane Air Discharge at Atmospheric Pressure

One of the major obstacles to obtain stable atmospheric-pressure non-equilibrium air plasma source for long-term operation is the plasma instability, particularly the corona-to-spark transition, corona-to-glow transition and glow-to-arc/spark transition. Two or three mode transitions of air discharge at atmospheric pressure are observed in previous works [1]–[2], and while the transition boundary and the physical mechanism are not well understood. Therefore, the aim of this study is to demonstrate all possible discharge modes in air and study on their characteristics and mode transitions.