Microwave Imaging Reflectometry in LHD

Abstract

Microwave Imaging Reflectometry (MIR) is under development for 2-D/3-D measurement of the electron density fluctuations in Large Helical Device (LHD). A rotatable ellipsoidal mirror has been installed inside the vacuum chamber of LHD in order to optimize the illumination beam angle vertically and horizontally. The illumination and reflected beam paths near the reflection surface are calculated by using the ray-tracing code. The illumination angles are optimized in the plasma experiment.