Characterization of a surface wave argon discharge sustained by microwave

Summary form only given. An experimental set-up for production of surface wave discharge in argon has been developed and is reported in this paper. A 600 W -2.45 GHz quasi-cw magnetron was used as microwave source which was coupled to the microwave circuit through an electric probe. A microwave resonator was built to operate as the electromagnetic launcher. The resonator, instead of the conventional coaxial type, consists basically of a WR-340 rectangular waveguide having at one end a precision microwave sliding short-circuit. A circular iris was used to couple the microwave source to the resonator. A glass discharge tube of 2.2 cm O.D., 1.8 mm thick and 1.5 m in length was placed in the resonator and by adjusting the sliding short-circuit position and the screw tuner it was possible to match the electromagnetic pattern in the resonator with the argon discharge tube. The microwave resonator was built to operate in a TE/sub 101/ mode in order to be able to excite a TM/sub 01/ mode in the plasma column. The discharge was operated in the 1-10/spl times/10/sup -2/ Torr pressure range in order to obtain a pressure versus column length characteristic curve.