Heidelberg 1999 – scientific programme

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P: Plasmaphysik

P 13: Entladungen III

P 13.4: Talk

Thursday, March 18, 1999, 15:00–15:15, ZO 2

Excimer Generation in Microhollow Cathode Discharges and its Applications — •Robert H. Stark, Ahmed El-Habachi, and Karl H. Schoenbach — Physical Electronics Research Institute, Old Dominion University, Norfolk, VA 23529, USA

By reducing the diameter of the cathode opening to values on the sub millimeter range we were able to operate discharges in argon and xenon in a direct current mode up to atmospheric pressure. The large concentration of high-energy electrons in MHCDs, in combination with high pressures favors three body processes such as excimer formation. This was confirmed by experiments in xenon and argon where emission of excimer radiation at 172 nm and 130 nm, respectively, was observed when the pressure was increased beyond 50 torr. Efficiencies of 6% to 9% have been achieved. Further increase of the efficiency seems to be possible by optimizing the discharge operation and electrode geometry. The possibility to form arrays of these discharges will allow the generation of flat panel excimer lamps with radiant emittances exceeding 60 W/cm2 by using multiple discharges in parallel. These low costs, excimer lamps provide an interesting and promising alternative to commercially available lamps.

This work is supported by the U.S. Department of Energy (DoE), Advanced Energy Division, and the National Science Foundation (NSF).