Laboratory Characterization of an Imaging Reflectometer System
Authors: T. Munsat, E. Mazzucato, H. Park, C.W. Domier, N.C. Luhmann, Jr., A.J.H. Donné, and M. van de Pol
Date of PPPL Report: January 2003
Published in: Plasma Physics and Controlled Fusion 45 (2003) 469-487
While microwave reflectometry has proven to be a sensitive tool for measuring electron density fluctuations in many circumstances, it has also been shown to have limited viability for core measurements and/or conditions of strong turbulence. To this end, a new instrument based on 2-D imaging reflectometry has been developed to measure density fluctuations over an extended plasma region in the TEXTOR tokamak. Laboratory characterization of this instrument has been performed using corrugated reflecting targets as an approximation to plasma reflections including 2-D turbulent fluctuations of various magnitude and poloidal wavenumber. Within this approximation, the imaging reflectometer can recover the spectral and spatial characteristics of the reflection layer lost to or otherwise inaccessible to conventional techniques.