Measurement Of RF-atmospheric Pressure Glow Jet By Microwave Resonance Probe

The diagnostic method of radio-frequency atmospheric pressure glow jet(RF-APGJ) by microwave resonance probe, which based on the principle of thetransmission line were studied. The interference between the probe and the dischargerwas analyzed by simulation, and a technique to eliminate the interference was alsofound. We used the optimized microwave resonance probe to measure the electrondensity of RF-APGJ at different powers.In the actual operation of the experiment, it was observed that the reflectionspectrum of the probe would be obviously interfered when the probe approaching thedischarger. So, the interference problems were discussed firstly. We established asimple physical model and operated a series of simulations for probe interferenceproblems in order to find ways to eliminate interference. The main work was to adddifferent shielding materials to the probe at the shorted end and find the best one toeliminate interference.Secondly，we diagnosed the RF-APGJ by the optimized microwave resonanceprobe. It was observed that the FWHM of reflection resonance spectrum wasinfluenced by RF-APGJ at different discharge power. The FWHM of reflectionresonance spectrum became widen with the increase of discharge power. When theflow rate of helium increased at a constant power (66W), the FWHM became widenas well. Furthermore, when the flow rate of oxygen in the mixed gas increased from0to40sccm, the FWHM became narrowed.Finally, the optical emission spectrum of RF-APGJ was also measured, and the electron temperature of helium RF-APGJ was calculated by the Saha-Boltzmanndistribution at different power. Based on the theoretical formula, the deduced electrondensity was approximately in the order1016m-3.