Pulsed Streamer Discharges Generated by Sub-Microsecond Pulsed Power in Air

The non-thermal, chemically active plasma is one of the promising technologies for the removal of the hazardous environmental pollutants. Pulsed streamer discharges in atmospheric pressure gases have received a great deal of interest for many years. It is very important to know the propagation mechanism of streamer discharges in order to improve the energy efficiency of pulsed discharge systems. In the present work, a Blumlein generator that has a pulse width of 100 ns was used to investigate the streamer discharge propagation. The propagation images in a coaxial reactor were taken by a streak camera for both positive and negative polarities of the applied voltage. From the results, primary and secondary streamers were observed propagating from the inner wire electrode to the outer cylinder electrode, and the maximum propagation velocity of the streamer head were 0.6 - 1.2 mm/ns in the range of 43 - 93 kV of the absolute value of the applied voltage. The propagation velocity of the positive streamer was faster than that of the negative polarity. The electric field at the wire electrode for streamer onset was 12 MV/m for the positive streamer and 20 MV/m for the negative streamer.