Characterization of Discharges in Atmospheric Pressure Air at 300-1000 KGenerated by Nanosecond Pulses Repetitively Applied at 2-30 kHz

摘要

Nanosecond repetitively pulsed discharges have been generated in atmospheric pressure air in avertical pin-to-pin electrode configuration. Corona-, diffuse-, and filamentary-like regimes andtransitions between them were characterized for various applied voltages (5-8 kV), gastemperatures (300-1000 K), pulse repetition frequencies (2-30 kHz), gap distances (1-7 mm), andairflow velocities (1-17 m/s). The energy deposited in the discharge was deduced from current andvoltage measurements. The spatial and/or temporal evolution of excited species densities forN2?, N2(B), NO(A), N2 + (B), and O(3p 5 P) were determined using absolute intensity-calibratedemission spectroscopy. Differences in the discharges' electrical current, emission intensity, andgas heating distinguished the regimes. For the diffuse-like state, an ionization wave propagatingfrom the anode to the cathode shortly after application of the high-voltage pulse was observed.