Effect of a high-voltage mesh electrode on the volume and surface characteristics of pulsed dielectric barrier discharges

M Kettlitz,H Höft,O Van Rooij,R Brandenburg,A Sobota

doi:10.1063/5.0032342

Abstract

Electrical breakdown in a pulsed asymmetric dielectric barrier discharge between a glass-covered mesh electrode and a grounded metal electrode in the air at atmospheric pressure is investigated. Volume discharge forms between the metal tip and the dielectric surface and spreads over the dielectric surface. Breakdown and discharge behaviors depend on the polarity of the charged electrode covered with glass compared to the metal rod electrode. In the case of the dielectric cathode (covered mesh), volume discharge features a stronger and longer-lasting emission. Volume discharge is weaker with outstretched surface discharge developing on the opposite glass electrode sustained by the embedded mesh when the metal rod functions as a cathode. The development and spatial distribution of the surface discharge depend on the relative polarity of the dielectrics caused by the charge deposition of the preceding discharge and is independent of the polarity of the applied high voltage. The discharge emission is brighter for the metal cathode and dielectric anode than for the metal anode, with a branching discharge developing and spreading in a star-like structure along the embedded grid, while a ring-like structure was observed for the metal anode and dielectric cathode. The duty cycle influences the discharge development and properties through the effects of the gas phase and surface pre-ionization.

Highlights

Due to their operation at atmospheric pressure and their scalability, dielectric barrier discharges (DBDs) have many different applications
The aim of this study is to investigate the discharge behavior in the volume and on the surface of an asymmetric DBD with a thin dielectric layer covering a fine mesh electrode and analyze the coaction of volume and surface discharges
During the rising slope and the falling slope of the applied voltage pulse, only one discharge occurred for each slope

Summary

Introduction

Due to their operation at atmospheric pressure and their scalability, dielectric barrier discharges (DBDs) have many different applications. The surface of the human body is anything but homogeneous or regular, which has motivated the design of flexible DBDs, e.g., a surface DBD incorporating thin (50 μm) polymer dielectric barriers.. The surface of the human body is anything but homogeneous or regular, which has motivated the design of flexible DBDs, e.g., a surface DBD incorporating thin (50 μm) polymer dielectric barriers.12 Another problem is the filamentary and, erratic structure of the DBD in most molecular gases, including the air. An attempt to improve the surface uniformity of filamentary DBDs is the use of thin mesh electrodes covered by a dielectric.. In combination with a thin dielectric barrier, distinct but uniformly distributed spots with a maximum electric field strength are present in the discharge gap near the surface. The use of metal and dielectric electrodes in one arrangement leads to asymmetric discharges with higher discharge intensity and streamer velocities.

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