Discharge analysis and electrical modeling of a coaxial dielectric barrier discharge (DBD) lamp

Dielectric barrier discharges (DBDs) occur by the presence of at least one insulating layer in contact with the discharge between two planar or cylindrical electrodes connected to an AC or pulse power supply. Dielectric barrier discharge (DBD) consists of filamentary micro-discharges under nonequilibrium, atmospheric pressure plasma condition. The ignition of discharges occurs when the applied voltage reaches the value of breakdown voltage, which depends on the operating frequency, the relative permittivity of the dielectric and the radial distance of cylindrical geometry employed. To check the dependency on these factors the experiments have been performed under different voltages, frequencies, gaps and dielectrics. The coaxial DBD tubes made of quartz (gas gap: 1-2 mm) filled with Ar/Xe gas at different pressure were used. A sinusoidal voltage up to 4.8 kV peak to peak with frequencies from 20 to 100 kHz has been applied to the discharge electrodes for the generation of microdischarges. By comparisons of visualization images and electrical waveforms, the filamentary discharges have been confirmed. An electrical model has been proposed using MATLAB Simulink to simulate the experimental results of filamentary discharges. The aim of this paper is to explain all the electrical phenomena involved during discharge. A good correlation between the experimental and simulated results have been found, which is used to deduce circuit impedance and other electrical parameters during discharges.