A study on plasma diagnostics by quasi-optical resonator method

A quasi-optical resonator system for plasma's non-intrusive diagnosis is presented. The test system includes xenon-lamp, quasi-optical resonant cavity, vector network analyzer and mobile platform. Before and after adding plasma to the resonant cavity, the change of resonance frequency and quality factor can be detected by vector network analyzer. According to the perturbation theory, plasma's parameters could be given by calculation. By changing xenon-lamp's position in the quasi-optical cavity, a wider range of concentration can be calculated in different electric field strength. Reliability of the quasi-optical system for plasma diagnostics is verified through analyzing the results.