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Title: Faraday-effect polarimeter-interferometer system for current density measurement on EAST

A multichannel far-infrared laser-based POlarimeter-INTerferometer (POINT) system utilizing the three-wave technique is under development for current density and electron density profile measurements in the EAST tokamak. Novel molybdenum retro-reflectors are mounted in the inside wall for the double-pass optical arrangement. A Digital Phase Detector with 250 kHz bandwidth, which will provide real-time Faraday rotation angle and density phase shift output, have been developed for use on the POINT system. Initial calibration indicates the electron line-integrated density resolution is less than 5 × 10{sup 16} m{sup −2} (∼2°), and the Faraday rotation angle rms phase noise is <0.1°.
Authors:
; ; ; ; ; ; ; ; ; ;  [1] ; ;  [2] ; ;  [1] ;  [3]
  1. Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China)
  2. Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095 (United States)
  3. (China)
Publication Date:
OSTI Identifier:
22303826
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 85; Journal Issue: 11; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; CALIBRATION; CURRENT DENSITY; ELECTRON DENSITY; FARADAY EFFECT; HT-7U TOKAMAK; INTERFEROMETERS; LASERS; MOLYBDENUM; PHASE SHIFT; POLARIMETERS; RESOLUTION