Spatiotemporally resolved characteristics of arc plasma in non-thermal multi-arc generator at atmospheric pressure

The spatiotemporally resolved characteristics of arc plasma in a non-thermal multi-arc generator with three high-voltage electrodes and a common grounded one were investigated by means of arc current signal, discharge image signal, and image analysis. Experimental results show that the spatial distribution of multi-arc plasma can be adjusted by the gas flow rate, and multi-arc plasma tends to distribute in the center of the arc chamber with the decrease in the gas flow rate. Once the confluence of three independent arc columns occurs, a common arc root will be shared by three arcs. The common arc-root attachment varies between constricted state and diffuse state, and the variation duration was in a cycle of about 1 ms, which is associated with beat vibration caused by the small deviation among the frequencies of three arc currents. This phenomenon suggests that the size of the arc root attachment can be adjusted by means of the frequency of the driving power supply.