An analysis of streamer discharge using a high-speed camera

Summary form only given, as follows. Pulsed streamer discharges have been extensively used in many applications such as control of NO/sub x/ and SO/sub x/ from flue gases, treatment of dioxins, removal of VOC (Volatile Organic Compounds) and in some ozonizers. A high efficiency operation is necessary for practical applications. Knowledge of the mechanism of streamer discharge propagation is important for the endeavor currently going on worldwide to improve the, effectiveness of the pulsed discharge systems. In the present work a coaxial cylindrical electrodes is used. The central electrode was made of stainless steel and had a diameter of 0.5 mm and the outer electrode was made of copper and had an inner diameter of 76 mm and a length of 10 mm. A short length was necessary to observe the streamers clearly. A pulsed voltage of 70 kV and 200 ns width was applied across the electrodes from a Blumlein generator. Extensive photographs were taken for a wide range of conditions with a resolution of 15 ns. It has been found that the streamer started from the inner electrode and reached the outer electrode in about 80 ns. This leads to an average propagation velocity of the streamers of 5/spl times/10/sup 7/ cm/s. The results will be discussed in relation to a variety of practical conditions.