Streamer Propagation of Positive and Negative Pulsed Corona Discharges in Air

Streamer propagation of positive and negative pulsed corona discharges is observed using streak and ICCD cameras. The discharge occurs in a 13-mm point-to-plane gap in dry air. In the positive discharge, the primary streamer propagates from the point to the plane, and then, the secondary streamer develops from the point to the middle of the gap. When the voltage is high, a midgap streamer is also observed. In the negative discharge, the primary streamer develops from the point to the plane, and then, an anodic channel develops from the plane to the middle of the gap. The velocity and luminous intensity of the primary streamer in the positive discharge increase as the streamer propagates from the point to the plane, while those in the negative discharge show an opposite tendency.