A W-band transmission measurement system for plasma diagnosis

A non-interventional plasma diagnosis method based on millimeter transmission theory over W-band is proposed in this paper. The attenuation and phase change of electromagnetic wave through plasma were measured by the w-band transmission measurement system. The transient change curves of electron density and collision frequency in the shock tube are obtained by the test data. Moreover, the effects of air pressure and the speed of shock wave on the plasma are analyzed.