Dynamic Evolution of Helium Atmospheric Pressure Plasma Jet With ITO-PET Electrodes

A helium atmospheric pressure plasma jet configured with transparent double ring electrodes is driven by an ac high voltage power, and its dynamic evolution in a whole cycle is carefully investigated with ns scale intensified-charge coupled device images. During the positive current pulse, a plasma bullet appears at downstream of active electrode and donut shape plasma presents inside ground electrode, respectively, and wavepacket-like behavior emerges in Dielectric Barrier Discharge (DBD) zone. However, for negative current pulse, the phenomena with double plasma bullets occur beneath active electrode, and plasma inside ground electrode is formed via overflow of diffuse plasma in DBD zone.