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Title: Recent developments of the JET far-infrared interferometer-polarimeter diagnostic

Journal Article · · Review of Scientific Instruments
DOI:https://doi.org/10.1063/1.3478146· OSTI ID:22055793
 [1]; ;  [2];  [3]
  1. EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom)
  2. Associazione EURATOM-ENEA, University of Rome ''Tor Vergata'', 00173 Roma (Italy)
  3. Consorzio RFX, Assoc. EURATOM ENEA sulla Fusione, Corso Stati Uniti 4, I-35127 Padova (Italy)

The far-infrared diagnostic provides essential internal measurements of the plasma density and magnetic field topology (q-profile via Faraday rotation angle) in real-time. The diagnostic capabilities have recently been extended in a number of key areas. Fast interferometer data, with 10 {mu}s time resolution, and a new MATLAB code have allowed improved analysis of the evolution of density profiles during fast events such as vertical plasma displacements, edge localized mode, pellet fuelling, and disruptions. Using the polarimeter measurements in real-time, a new calibration procedure has been developed based on a propagation code using the Mueller matrix formalism. A further major upgrade of the system is presently underway: adding a second color laser to the vertical channels and implementing a new phase counter based on analog zero crossing and field-programmable gate array boards.

OSTI ID:
22055793
Journal Information:
Review of Scientific Instruments, Vol. 81, Issue 10; Other Information: (c) 2010 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
Country of Publication:
United States
Language:
English