Influence of test conditions on dielectric barrier discharges operating in air with flowing helium

Dielectric barrier discharge (DBD) tests were carried out in an air gap with flowing helium. Through photos taken from discharges between transparent water electrodes, influence of some test conditions on characteristics of DBD was invested. The conditions included amplitude and frequency of applied voltage, velocity of gas flow, distance of gas gap, and thickness of barriers. The results show that when applied voltage amplitude, frequency, or velocity of helium flows increase, the filamentary discharge seems to transfer into a diffuse one by naked eyes. But the discharge current behaves more pulses not one in glow discharge.