Characteristics of non-thermal AC arcs in multi-arc generator

To obtain large-volume non-thermal arc plasma (NTAP), a multiple NTAP generator with three pairs of electrodes has been developed. The arc plasma characteristics, including dynamic process, spatial distribution and rotation velocity in discharge zone, were investigated by high speed photograph and image processing methods. Results showed that the dynamic behaviors and spatial distribution of arc plasma were strongly related to the electrode configuration. A swirl flow of multi-arc plasma is formed by adjusting electrode configuration, and a steady luminance area is clearly observed in the center of discharge zone. Moreover, the size of the luminance area increased with decreasing the gas flow rate. The electrical connection in series can be formed between/among these arc columns with their respective driving power supplies in multi-arc dynamic evolution process. An approximately periodical process of acceleration and deceleration of the arc rotation velocity was observed in multi-arc generator with swirl flow configuration. In general, the mean velocity of arc rotation was higher in multi-arc generator with swirl flow configuration when a pair of electrodes driven by a power supply are opposite each other rather than adjacent.