Characteristics of impurity-dependent breakdown in helium dielectric barrier discharge jets

Abstract

Multiple current pulses during breakdown (or so-called pseudoglow discharge1) in floating-electrode dielectric barrier discharge jets (DBD jets) were studied in this work. Industrial grade helium (purity 99.995 %) and the helium with impurity were employed for the DBD jet generation. Preliminary works used methyl methacrylate (MMA, ∼1800 ppm) as the added impurity. Based on the electrical characteristics, both the jets show the characteristics of multiple current pulses during breakdown but contained different numbers, widths, and sequencing of current pulses, as shown in Fig. 1. In the pure helium DBD jet, several relatively small pulses form a single broad current pulse per half-cycle, while with MMA several more widely separated current pulses occur. It was also seen that the number of the current pulses in the helium and helium/MMA DBD jets increases with the rising power.