Bonn 2000 – wissenschaftliches Programm

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P: Plasmaphysik

P 20: Entladungen (Poster)

P 20.25: Poster

Donnerstag, 6. April 2000, 17:00–19:30, Aula

Atmospheric Pressure Glow Discharges in Air — •Robert H. Stark¹, Uwe Ernst², Klaus Frank², and Karl H. Schoenbach¹ — ¹Physical Electronics Research Institute, Old Dominion University, Norfolk, VA 23529, USA — ²Institute of Physics, University of Erlangen, Germany

Direct current glow discharges have been operated in atmospheric pressure air by using microhollow cathode discharges as plasma cathodes. The microhollow cathode discharge serves as electron emitter to support stable high-pressure glow discharge operation. It could be shown that the glow discharge current could be controlled linearly by the plasma cathode current at constant electric field across the glow. Stable dc glow discharge operation have been demonstrated up to approximately 20 mA. Pulsed operation allowed us to increase the current to approximately 100 mA in the microsecond time regime before glow-to-arc transition occurs. The observed positive slope in the V-I characteristic at these high currents indicates that parallel operation of these discharges is possible when the discharges are operated in the pulsed mode. The electron density in the atmospheric pressure glow is on the order of 10¹² to 10¹³ cm⁻³. A gas temperature of 2000 K was determined by using emission spectroscopy of rotational nitrogen states. The electrical power necessary to sustain these atmospheric pressure air glows is on the order of 5 kW/cm⁻³, which is in agreement with theoretical calculations. This work was funded by the Air Force Office of Scientific Research (AFOSR) and the National Science Foundation (NSF), and Deutscher Akademischer Austauschdienst (DAAD).