Statistical analysis of pulsed micro-discharges and ozone generation in dielectric barrier discharges

Pulsed micro-discharges produced by dielectric barrier discharges (DBDs) in a sub-millimeter gap were investigated under 200 cycles of sinusoidal ac voltage at 5 kHz in this work. The impulsive current in the external circuit was accurately measured by an oscilloscope with a bandwidth of 2.5 GHz and maximum sampling rate of 40 GS/s to calculate the filamentary current in the discharge gap. The amplitude, pulse duration and transferred charge of a single filamentary current and the micro-discharge energy acquired over the 200 voltage cycles were statistically analyzed for different discharge gaps and gas pressures. The micro-discharge parameters and ozone generation efficiencies for different conditions were compared. The ozone production efficiency was found to increase with increasing pressure from 1 bar absolute to 2 bar absolute, and the gap length from 0.2 mm to 0.5 mm. The maximum ozone production efficiency achieved in the work was 217 g/kWh, with a gap length of 0.5 mm, 2.0 bar absolute pressure, and an applied voltage of 5.5 kV at 5 kHz.