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Title: Simultaneous Cotton-Mouton and Faraday rotation angle measurements on JET

Abstract

The change in the ellipticity of a laser beam that passes through plasma due to the Cotton-Mouton effect can provide additional information on the plasma density. This approach, complementary to the more traditional interferometric methods, has been implemented recently using the JET interferometer-polarimeter with a new setup. Routine Cotton-Mouton phase shift measurements are made on the vertical central chords simultaneously with the Faraday rotation angle data. These new data are used to provide robust line-integrated density measurements in difficult plasma scenarios, with strong Edge Localized Modes (ELMs) or pellets. These always affect interferometry, causing fringe jumps and preventing good control of the plasma density. A comparison of line-integrated density from polarimetry and interferometry measurements shows an agreement within 10%. Moreover, in JET the measurements can be performed close to a reactor relevant range of parameters, in particular, at high densities and temperatures. This provides a unique opportunity to assess the quality of the Faraday rotation and Cotton-Mouton phase shift measurements where both effects are strong and mutual nonlinear interaction between the two effects takes place.

Authors:
; ;  [1]
  1. EURATOM/UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom)
Publication Date:
OSTI Identifier:
20861354
Resource Type:
Journal Article
Journal Name:
Review of Scientific Instruments
Additional Journal Information:
Journal Volume: 77; Journal Issue: 10; Other Information: DOI: 10.1063/1.2229169; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0034-6748
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; CONTROL; EDGE LOCALIZED MODES; FARADAY EFFECT; INTERFEROMETERS; LIGHT TRANSMISSION; NONLINEAR PROBLEMS; PHASE SHIFT; PLASMA; PLASMA CONFINEMENT; PLASMA DENSITY; PLASMA DIAGNOSTICS; TOKAMAK DEVICES; VOIGT EFFECT

Citation Formats

Boboc, A, Zabeo, L, Murari, A, and Consorzio RFX, Associazione EURATOM-ENEA sulla Fusione, Corso Stati Uniti 4, I-35127 Padova. Simultaneous Cotton-Mouton and Faraday rotation angle measurements on JET. United States: N. p., 2006. Web. doi:10.1063/1.2229169.
Boboc, A, Zabeo, L, Murari, A, & Consorzio RFX, Associazione EURATOM-ENEA sulla Fusione, Corso Stati Uniti 4, I-35127 Padova. Simultaneous Cotton-Mouton and Faraday rotation angle measurements on JET. United States. https://doi.org/10.1063/1.2229169
Boboc, A, Zabeo, L, Murari, A, and Consorzio RFX, Associazione EURATOM-ENEA sulla Fusione, Corso Stati Uniti 4, I-35127 Padova. Sun . "Simultaneous Cotton-Mouton and Faraday rotation angle measurements on JET". United States. https://doi.org/10.1063/1.2229169.
@article{osti_20861354,
title = {Simultaneous Cotton-Mouton and Faraday rotation angle measurements on JET},
author = {Boboc, A and Zabeo, L and Murari, A and Consorzio RFX, Associazione EURATOM-ENEA sulla Fusione, Corso Stati Uniti 4, I-35127 Padova},
abstractNote = {The change in the ellipticity of a laser beam that passes through plasma due to the Cotton-Mouton effect can provide additional information on the plasma density. This approach, complementary to the more traditional interferometric methods, has been implemented recently using the JET interferometer-polarimeter with a new setup. Routine Cotton-Mouton phase shift measurements are made on the vertical central chords simultaneously with the Faraday rotation angle data. These new data are used to provide robust line-integrated density measurements in difficult plasma scenarios, with strong Edge Localized Modes (ELMs) or pellets. These always affect interferometry, causing fringe jumps and preventing good control of the plasma density. A comparison of line-integrated density from polarimetry and interferometry measurements shows an agreement within 10%. Moreover, in JET the measurements can be performed close to a reactor relevant range of parameters, in particular, at high densities and temperatures. This provides a unique opportunity to assess the quality of the Faraday rotation and Cotton-Mouton phase shift measurements where both effects are strong and mutual nonlinear interaction between the two effects takes place.},
doi = {10.1063/1.2229169},
url = {https://www.osti.gov/biblio/20861354}, journal = {Review of Scientific Instruments},
issn = {0034-6748},
number = 10,
volume = 77,
place = {United States},
year = {2006},
month = {10}
}