Study of the characteristic differences of positive and negative half-cycles from atmospheric pressure glow discharge driven by resonant AC voltage

There are many advantages in obtaining low-temperature plasmas that are rich in active particles by atmospheric pressure glow discharge, so there has been a lot of research on the acquisition method and application of it. However, there is a lack of knowledge about the mechanism of atmospheric pressure glow discharge driven by an AC resonant power supply. In this paper, we describe our study of the characteristic differences between half-cycle positive and negative atmospheric pressure glow discharges driven in open air by an AC resonant power supply, and we describe our analysis of the associated physical mechanism. The comparison and analysis of experimental results indicate that both positive-cycle and negative-cycle discharges led to typical glow discharge and no streamer discharge appeared in the discharge process. There were still charged particles in the discharge channel when the discharge current was zero. With increasing amplitude of the output voltage of the power supply, the glow area near the electrode surface and the plasma distribution area in the discharge channel increased. When the output voltage of the power supply was low, the negative polarity discharge was more likely to form in the gap of the pin-to-plate electrode. In the AC discharge process, the α-mode discharge was dominant, and the developing speed of the positive-cycle discharge was faster than that of the negative-cycle discharge. The polarity effect became less obvious with the increase in the output voltage amplitude of the power supply.