Influence of the dielectric thickness on the homogeneity of a diffuse dielectric barrier discharge in air

This work focuses on a diffuse Dielectric Barrier Discharge (DBD) in atmospheric pressure air using an original experimental approach. In air, the role of the capacitance on the discharge regime has not yet been studied even though it affects the discharge current. To address this gap in knowledge, the dielectric capacitance was modified by the means of the dielectric thickness in a plane-to-plane DBD configuration. The discharge regime was analyzed using short exposure time photographs and electrical measurements in order to remove any potential uncertainties regarding the diffuse nature of the DBD in atmospheric pressure air. The influence of the dielectric capacitance on the discharge regime was analyzed thanks to the working domain of the discharge. Additionally, using an original electrical model of the discharge, the effective surface and current density of the discharge was obtained only from electrical measurements. Thus, the crucial role of the maximum current density on the discharge regime was highlighted. The control of the current density by the means of the dielectric capacitance led to the obtention of a diffuse discharge at a frequency up to 5 kHz for the very first time. Considering this high frequency, the possibility of using a DBD in air at atmospheric pressure for coating applications is discussed.