Investigation on the Micro-Discharge Characteristics of Dielectric Barrier Discharge in a Needle-Plate Geometry

In this study, a dielectric barrier discharge device with needle-plate electrodes wasused to investigate the characteristics of the micro-discharge in argon at one atmospheric pressureby an optical method. The results show that there are two discharge modes in the dielectric barrierdischarge, namely corona mode and filamentary mode. The corona discharge only occurs in thevicinity of the needle tip when the applied voltage is very low. However, the filamentary dischargemode can occur, and micro-discharge bridges the two electrodes when the applied voltage reachesa certain value. The extended area of micro-discharge on the dielectric plate becomes largerwith the increase in applied voltage or decrease in gas pressure. The variance of the light emissionwaveforms is studied as a function of the applied voltage. Results show that very narrow dischargepulse only appears at the negative half cycle of the applied voltage in the corona discharge mode.However, broad hump (about several microseconds) can be discerned at both the negative halfcycle and the positive half cycle for a high voltage in the filamentary mode. Furthermore, theinception voltage decreases and the width of the discharge hump increases with the increase inapplied voltage. These experimental phenomena can be explained qualitatively by analyzing thedischarge mechanism.