Observation of the stripe and filamentary self-organized structure of atmospheric pressure nitrogen microgap dielectric barrier discharge*

A dielectric barrier discharge (DBD) is a discharge caused by an alternating voltage applied to a pair of electrodes, one or both of which are covered in the dielectric material. Microplasmas generated by DBD have been observed to self-organize their discharge structure under certain conditions. Self-organization is an undesirable nonuniform discharge in several industrial applications; however, the periodic discharge structure generated by self-organization has recently been applied to plasma photonic crystals. With short-time observation techniques, hexagonal lattice structures and stripe structures in helium microgap DBDs are visually observed, and stripe structures are shown to be composed of hexagonal structures. There are several examples of observations of stripe structures in the case of N2 discharge, but no observations of discharge phases on a short-time scale have been reported.

In this study, the discharge phase of an atmospheric pressure nitrogen microgap dielectric barrier discharge self-organized structure was observed. Stripe structures were observed in discharge patterns with two peaks of discharge current under conditions of long exposure time and a high number of integration times. In the discharge region, with an exposure time of 1 µs and several integrations of 1, discharges with a random arrangement of large and small filaments were observed. The average movement speed of the filament was estimated to be at least 62.5 mm/s.