Discharge characteristics of pin-micron droplet-pin system driven by DC pulse voltage

The multi-phase discharge with the gas-liquid interface has attracted a lot of interest and especially the plasma biomedicine application has become the research hotpot in recent years. Considering the size effect of the gas and liquid phases, this paper focuses on the discharge processes based on the micron droplet system with a pin-to-pin electrode excited by the high DC pulse voltage with 30 ns rising time. The main innovation of this article is the droplet diameters varying from 300 mu m to 600 mu m. The image shows that the discharge always develops along the surface of the droplet, and the droplet appears to have the effect of guiding the ionizing wave. And the discharge affects the shape of the droplet. When the applied voltage (U-A) is different, the difference between with droplet and without droplet inside the electrodes shows reverse characteristics. When U-A is 10 kV, the emission duration time and area of the without droplet case is larger than that with the droplet while the result is the opposite for when U-A is 40 kV. There is a pre-breakdown channel before the ellipsoidal discharge and the pre-breakdown channel is related to the electrode-droplet position. And the pre-breakdown channel always propagates along the droplet surface.