Millimeter wave imaging diagnostic for simultaneous density and temperature fluctuation measurements on the TEXTOR Tokamak

A millimeter wave imaging diagnostic for simultaneous density and temperature fluctuation measurements has been developed for operation on the TEXTOR Tokamak. The system is based on the quasi-optical imaging of the radiation from the plasma onto state-of-the-art millimeter wave mixer/receiver arrays. The temperature (fluctuation) measurements are based on the observation of electron cyclotron emission from a 2D plasma area with 8×16 sample volumes of about 1 cm³. The density fluctuation measurements are based on active probing by means of reflectometry. In this case reflections from 16 sample volumes, arranged along the cutoff surfaces are diagnosed. The combined millimeter wave imaging diagnostic offers distinct advantages above the commonly used non-imaging diagnostics.