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Indexed by:期刊论文

Date of Publication:2009-04-01

Journal:PHYSICS OF PLASMAS

Included Journals:SCIE、EI

Volume:16

Issue:4

ISSN No.:1070-664X

Abstract:Two homogeneous discharge modes, Townsend discharge and glow discharge, can be obtained in dielectric barrier discharges at atmospheric pressure when an external voltage with an appropriate frequency is applied to the electrodes. In this paper, a one-dimensional self-consistent model was used to investigate the transition and the difference in characteristics of these two modes. The simulation results showed that the spatiotemporal distributions of the electron temperature in the two discharge modes differed noticeably. In the glow discharge, the electron temperature in the cathode fall was several times higher than that in any of the other regions; in contrast, the electron temperature in the Townsend discharge was approximately spatially uniform. The electron energy distribution functions (EEDFs) at different locations in the discharge gap at the discharge current peaks were given and analyzed. In the glow discharge, the EEDF in the cathode fall region contained the largest percentage of high energy in all regions, and the majority of the electrons in the negative glow region possessed very low energy. However in the Townsend discharge, the EEDFs at different locations were similar to each other. In addition, both the discharge current density and the voltage drop on the discharge gas versus the applied voltage were also examined. It was found that when the applied voltage was over a critical value, the Townsend discharge turned into the glow discharge, the peak magnitude of the discharge current density increased abruptly. The maximum of the discharge current density was nearly a linear function of the applied voltage, while the voltage drop on the discharge gas was approximately a constant. Also, we found that there was a minimum of the applied voltage leading to the transition from the Townsend discharge to the glow discharge as the discharge gap spacing varied. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3109665]