Distribution Characteristics of Surface Charge of Dielectric Barrier Columnar Discharge in Atmospheric Helium

In dielectric barrier discharges, the surface charge on dielectric plate has a significant impact on the discharge. In order to further understand the influence of the surface charge on dielectric of columnar discharge, the distribution characteristics of the surface charge of dielectric barrier columnar discharge were analyzed by using the two-dimensional fluid model. And a comparison between the surface charge distribution of the dielectric barrier columnar discharges and the filament discharges was made. The results show that, during the process of columnar discharge, the surface charge density on the dielectric plates changes obviously in the columnar discharge area. While it changes slightly in the non-discharge-column area where strong Townsend discharge occurred and is nearly un-changed in the non-discharge-column area where weak Townsend discharge occurred. After the columnar discharge is extinguished, the distribution of surface charge on the dielectric plate in the columnar discharge area remains unchanged. And the distribution of the positive charge on the cathode dielectric plate presents a gaussian distribution, while the distribution of the negative charge on the anode dielectric plate presents a flat-top wave distribution. The full width at half maximum (FWHM) of the surface of the columnar discharge is twice of the filament discharge. These simulation results indicate the dielectric surface charge is the main reason for the memory effect of the dis-charge column, and contribute toward a better understanding of columnar discharges.