Distribution characteristics of nanosecond-pulsed surface dielectric barrier discharge at different electrode gaps

Electrode gap is an important geometric parameter in surface dielectric barrier discharge (SDBD). Based on experimental studies and simulations, the influence of electrode gaps on the distribution characteristics of nanosecond-pulsed SDBD is studied, and the mechanisms of two plasma distributions (quasi-diffuse mode and separated-channel mode) are analyzed theoretically. Experimental results show that electrode gap is the key geometric parameter accounting for the two typical discharge characteristics and different plasma distributions. Simulations of external electric fields of discharge areas present that the direct reasons of two plasma distributions are the morphological and numerical differences of external electric fields at different gaps. Combined with gas discharge theory, it is deduced that the quasi-diffuse distribution is due to that the streamers forward-expanding and spanwise-exciting ionization act simultaneously, while the separated-channel distribution is mainly because the streamer forward expanding is dominant and span-wide ionization is relatively weak. The main mechanisms are the match of the changing rate of electric field with time and space, and the expanding velocity of streamer channels. © 2017, The editorial office of Transaction of China Electrotechnical Society. All right reserved.