Effect of Polarity and Rise Time of Applied Pulsed Voltage on Streamer Discharge Phenomena

Pulsed streamer discharges have been extensively used in many applications such as control of $NO_X$ and $SO_2$ from exhaust gases, treatment of dioxins, removal of volatile organic compounds, generation of ozone and laser excitation. An operation with a high-energy efficiency is necessary for practical applications. It is very important to know the propagation mechanism of streamer discharges in order to improve the energy efficiency of pulsed discharge systems. In this paper, the emission from pulsed streamer discharges in a coaxial electrode system in air at 0.1 MPa was observed using a high-speed gated intensified charge-coupled display camera. A concentric wire-cylinder electrodes configuration was used. Positive and negative pulsed voltages having a width of about 200 ns were applied to the central electrode. From the results, the streamer discharges were initiated at the inner electrode and terminated at the outer electrode. It is suggested that the propagation velocity of the streamer discharges is being influenced strongly by the rise time and the polarity of the pulsed voltage.