Streamer propagation in CO₂ and N₂/CO₂ mixtures at atmospheric pressure

Abstract This study investigated streamer discharge in CO 2 and N 2 CO 2 mixtures. Experiments were conducted at atmospheric pressure and room temperature conditions by using a point-to-plane electrode configuration. A repetitive pulse discharge at 50 Hz was used to stabilise the discharge in CO 2 . Under these conditions, the discharge current and intensified charge-coupled device camera images were systematically analysed during streamer evolution in CO 2 . The results revealed that streamer propagation and electrical properties were considerably influenced by the N 2 concentration in CO 2 . Analysis of the emission of secondary streamers indicated that the emission ratio of primary streamers and secondary streamers in CO 2 differed considerably from that in air. The onset delay time of streamer discharge was measured and statistically processed based on previous studies of streamer onset processes. Findings indicated an increase in the discharge delay time and its dispersion when N 2 was added to CO 2 , which indicated that variations in the initial electron content affected the inception process of streamer discharge.