Low-pressure dielectric barrier discharges in argon : experimental investigations and modelling

The discharge behaviour of a dielectric barrier discharge (DBD) in low-pressure argon gas was investigated. Measurements of the electrical characteristics and light emission dynamics were compared to the results of a two-dimensional fluid model. Our investigations showed that the breakdown phase of our DBD was very similar to the ignition phase of a low-pressure glow discharge without dielectrics, described by Townsend theory. The effect of the dielectric material was limited to the decay phase of the discharge, where charging of the dielectrics quenched the discharge. Additionally, the argon metastable density could be monitored by measuring light emission from nitrogen impurities. A metastable density of about 5x1017 m-3 was present during the entire voltage cycle, with only a small (~5 %) increase during a discharge