Potential Application Of Microwave Diagnostics To RFP

KTX(Keda Torus Experiment)is one of the important(RFP)Reversed Field Pinch experimental devices.Its vast potential contribution to fusion science relies on its advanced plasma diagnostics.This paper discusses the possibility of three microwave diagnostics applied on KTX,including ECE(Electron Cyclotron Emission),Reflectometry and CTS(Collective Thomson Scattering),which serve to measure electron temperature profile,density profile and local ion temperature respectively.Compared with tokamak,Reversed Field Pinch confines plasma of higher density,higher magnetic shear and stronger fluctuation.ECE has to be operated on optical thin conditions due to the high density plasma,resulting in less signal intensity.This paper discusses the ECE signal intensity based on KTX parameters.The magnetic shear of KTX plasma leads to the coupling between O mode and X mode,violating the WKB assumption that is important to Reflectometry.This paper concludes that this coupling effect does not prevent reflectometry from measuring electron density of KTX if the polarization of the receiving antenna is properly aligned.Density fluctuation is another source of measurement error using reflectometry,which can be mitigated by increasing the speed of sweeping frequency.Collective Thomson Scattering tends to be influenced by the impurity,magnetic field and ECE background.This paper quantifies these effects and provides a design that avoids their influences.