Characteristics of Self-Organized Structure in Microgap Dielectric Barrier Discharge at Atmospheric Pressure

In the microplasma generated by dielectric barrier discharge (DBD), a huge variety of discharge patterns are generated by self-organization. In this study, we experimentally observed variation in the hexagonal structures in capacity-coupled microgap DBD using a helium (He)/argon (Ar) mixture. The spatial distribution of the self-organized structure was revealed via a discharge experiment in which the equivalent barrier capacitance was continuously changed within the range of 56–1500 pF. The results demonstrate that the lattice spacing of the patterns can be continuously controlled within the range of 1.22–1.59 mm for an equivalent barrier capacitance of 56–172 pF. It is likely that an increase in external capacitance increases the discharge cell voltage. In contrast, the lattice constant remained unchanged with an increase in barrier capacitance within a range of 172–1500 pF. The lattice spacing of the patterns could be continuously controlled within a range of 0.66–0.74 mm for all He/Ar gas mixing ratios.