A novel coplanar-volume coupled discharge with a capillary-to-plate configuration, in which a capillary coplanar dielectric barrier discharge (CDBD) functions as pre-ionization source and a negative DC voltage is introduced to extend the plasma region from dielectric surface to space, is proposed and investigated experimentally. Optical and electrical properties, streamer evolution and active species generation are systematically studied to obtain a deep insight into the plasma characteristics of coplanar-volume coupled discharge. Compared with traditional VDBD, the ignition voltage is reduced and discharge intensity is greatly enhanced in coplanar-volume coupled discharge under the effects of pre-ionization. Spatial-temporal evolution of streamer morphology demonstrates that there are two discharge processes of coupled primary discharge and coupled secondary discharge in coplanar-volume coupled discharge, which are respectively developed from the coplanar primary discharge and coplanar secondary discharge in capillary CDBD. By analyzing the effects of pulse and negative DC voltage on plasma characteristics, it is found that coplanar-volume coupled discharge shows stronger plasma light intensity, higher discharge energy and better discharge chemical activity under the same total discharge voltage.

coplanar-volume coupled discharge,capillary coplanar barrier discharge,pre-ionization,plasma characteristics