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Title: Correction of the spectral calibration of the Joint European Torus core light detecting and ranging Thomson scattering diagnostic using ray tracing

This work isolated the cause of the observed discrepancy between the electron temperature (T{sub e}) measurements before and after the JET Core LIDAR Thomson Scattering (TS) diagnostic was upgraded. In the upgrade process, stray light filters positioned just before the detectors were removed from the system. Modelling showed that the shift imposed on the stray light filters transmission functions due to the variations in the incidence angles of the collected photons impacted plasma measurements. To correct for this identified source of error, correction factors were developed using ray tracing models for the calibration and operational states of the diagnostic. The application of these correction factors resulted in an increase in the observed T{sub e}, resulting in the partial if not complete removal of the observed discrepancy in the measured T{sub e} between the JET core LIDAR TS diagnostic, High Resolution Thomson Scattering, and the Electron Cyclotron Emission diagnostics.
Authors:
 [1] ; ;  [2] ;  [3] ;
  1. FOM Institute DIFFER – Dutch Institute for Fundamental Energy Research, Association EURATOM-FOM, 3430 BE Nieuwegein (Netherlands)
  2. EURATOM-CCFE Fusion Association, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom)
  3. JBM Optique, 4 Rue du Calvaire Bâtiment 11, 92210 Saint Cloud (France)
Publication Date:
OSTI Identifier:
22220384
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 84; Journal Issue: 10; Other Information: (c) 2013 Euratom; 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; CORRECTIONS; CYCLOTRONS; ELECTRON TEMPERATURE; ELECTRONS; FILTERS; INCIDENCE ANGLE; JET TOKAMAK; OPTICAL RADAR; PHOTONS; PLASMA CONFINEMENT; PLASMA DIAGNOSTICS; RESOLUTION; RF SYSTEMS; THOMSON SCATTERING