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Patent Number: 6147452
Title:  AC glow plasma discharge device having an electrode covered with apertured dielectric
Inventors: Erich E. Kunhardt, Kurt H. Becker
Abstract: A method and apparatus for stabilizing glow plasma discharges by suppressing the transition from glow-to-arc includes a perforated or apertured dielectric plate having an upper surface and a lower surface and one or more holes extending therethrough. The perforated dielectric plate is positioned over the cathode. Each of the holes acts as a separate active current limiting micro-channel that prevents the overall current density from increasing above the threshold for the glow-to-arc transition. This allows for a stable glow discharge to be maintained for a wide range of operating pressures (up to atmospheric pressures) and in a wide range of electric fields include DC and RF fields of varying strength. In another embodiment, the device comprises an AC glow plasma discharge device wherein an apertured dielectric is placed over an electrode. The apertured dielectric may have one or more apertures or capillaries extending therethrough. The frequency of the AC source is adjusted to be matched to the characteristics of the apertured dielectric. At a proper frequency, jets come out of the apertures or capillaries, i.e. the capillaries get turned on and become electrodes to the opposite electrode. As such, the device goes from a glow state to a capillary plasma electrode discharge state. A second dielectric may be applied to the second electrode and the second dielectric may be solid or may be apertured.
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