Diagnostics of TM/sub 010/-mode microwave cavity discharges in CO/sub 2/-N/sub 2/-He laser gas mixtures. I. Measurement of dielectric constant

Plasma parameters in the microwave discharged CO/sub 2/ laser gas mixtures of CO/sub 2/-N/sub 2/-He=0.9/2.5/20 at 25 Torr obtained using the perturbation method for a TM/sub 010/-mode cylindrical resonant cavity were examined. From the changes in resonant frequencies and Q values of the cavity, dielectric constant of the discharged plasma under the condition of RF to laser output power conversion ratio of 14% at mass flow rate of 4.2 kg/h was determined to be nearly 0.96-0.01j. It was also obtained from the dielectric constants of the plasma that electron number density, the electron temperature, and discharge parameters (E/n) were (0.3-3)/spl times/10/sup 15/m/sup -3/, 0.5-2.7 eV, and (0.5-2)/spl times/10/sup -/15 Vcm/sup 2/, respectively.<
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