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.