Experimental study of nanosecond-pulse dielectric barrier discharge in open air

Dielectric barrier discharge (DBD) is an important method to produce non-thermal plasma in atmospheric air, which is widely used in a variety of industrial fields. In this paper, the discharge is generated in atmospheric air using a magnetic compression solid-state pulsed power generator. The output pulse can be up to 30 kV with a rise time of about 40 ns and a full width at half maximum of 70 ns. The characteristics are studied by the measurement of voltage and current waveforms, discharge images, and optical emission spectroscopy. The experimental results show that when the air gap is less than 3 mm, no filaments are observed and the DBD is diffuse in the whole discharge regime. The rotational and vibrational temperatures of the DBD are calculated according to the emission band of the nitrogen second positive system near 380.5 nm. The relationship between the emission intensity and the rotational temperature with the applied voltage and pulse repetition frequency are investigated and discussed. The experimental results show that the emission intensity is sensitive to the applied voltage and pulse repetition frequency; however the rotational and vibrational temperatures indicates insensitivity to the applied voltage and pulse repetition frequency.