Electrical and optical characteristics of radio-frequency atmospheric dielectric barrier discharge using anodic alumina barriers

It is widely accepted that dielectrically insulated electrodes can control plasma contraction in radio frequency atmospheric pressure glow discharge at very large currents. It is also known that thin dielectric barriers maximize the permissible discharge current, thus boosting the reactive plasma species and enhancing the application efficacy. An experimental investigation of radio-frequency atmospheric pressure dielectric barrier discharge (rf APDBD) using a thin layer of a novel dielectric, anodic alumina grown by a wet electrochemical process to insulate electrodes is presented in this paper to demonstrate that rf APDBD with anodic alumina barriers remains stable and retains volume without contraction over a wide current range in the & gamma;-mode. The electrical characterization of the rf APDBD is performed using an equivalent electric circuit model based on the measured electrical parameters. In normal glow discharge, the measured impedance data closely matched the simulated data. Optical emission spectroscopy demonstrated that a higher discharge current facilitated active plasma chemistry. The estimated excitation, vibrational, and gas temperatures indicate that rf APDBD with anodized electrodes is well suited for surface treatment and decontamination applications in open air.