Investigation of the dielectric barrier discharge properties in different gas mixtures

Experimental investigations of the dielectric barrier discharge (DBD), aimed at the study of the discharge properties at different gas mixtures, are presented. They are devoted to the time- and space-resolved measurements of the DBD radiation. Radiation of the molecular bands over the period of the applied voltage was investigated. The experimental setup allowed to collect radiation from the region near one electrode, The measurements revealed the dependence of the band intensities on the gas mixture and the polarity of the electrode. A range of gases in binary combinations of helium, argon and oxygen with nitrogen were explored. With the help of the well known method of Lissajous figure acquisition, the discharge was characterized electrically. The conditions chosen were typical for this kind of discharges: pressure 1 bar, room temperature, the frequency of the applied voltage 1 kHz. The power dissipated in the discharge was within limits of 10 watts. For some gas mixtures, measurements in the presence of a gas flow were performed. The results have shown that under given conditions, DBD exists in a filamentary form and only in few cases, one can obtain a homogeneous appearance. The change in the appearance corresponds to the changes of the emission intensities in the near-electrode region according to the polarity of the electrode. Also, it was found that the presence of the gas flow has no influence on the discharge properties examined here.