Experimental research on microdischarge characteristics of DBD

Summary form only given. Dielectric barrier discharge (DBD) consists of filamentary micro-discharges under nonequilibrium, atmospheric pressure plasma condition. The size and spatial distribution of microdischarge spots are of great importance to surface processing. In our experiment, water electrodes were used for visualization. Charge-coupled device and highspeed photography technology were used to capture the quasi-stationary and transient image of microdischarge spots. The microdischarge current and voltage waveforms were recorded by digital oscilloscope. A special circuit synchronized both optical device and oscilloscope. The experiments were done under different voltages, frequencies, gaps and dielectrics with nitrogen mixture flowing through the discharge chamber. By comparisons of visualization images and electrical waveforms, some interesting conclusions were drawn.