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Title: Electron kinetic effects on optical diagnostics in fusion plasmas

At anticipated high electron temperatures in ITER, the effects of electron thermal motion on Thomson scattering (TS), toroidal interferometer/polarimeter (TIP) and poloidal polarimeter (PoPola) diagnostics will be significant and must be accurately treated. We calculate electron thermal corrections to the interferometric phase and polarization state of an EM wave propagating along tangential and poloidal chords (Faraday and Cotton-Mouton polarimetry) and perform analysis of the degree of polarization for incoherent TS. The precision of the previous lowest order linear in τ = T{sub e}/m{sub e}c{sup 2} model may be insufficient; we present a more precise model with τ{sup 2}-order corrections to satisfy the high accuracy required for ITER TIP and PoPola diagnostics. The linear model is extended from Maxwellian to a more general class of anisotropic electron distributions that allows us to take into account distortions caused by equilibrium current, ECRH and RF current drive effects. The classical problem of degree of polarization of incoherent Thomson scattered radiation is solved analytically exactly without any approximations for the full range of incident polarizations, scattering angles, and electron thermal motion from non-relativistic to ultra-relativistic. The results are discussed in the context of the possible use of the polarization properties of Thomson scattered light as amore » method of T{sup e} measurement relevant to ITER operational scenarios.« less
Authors:
; ; ;  [1] ; ;  [2]
  1. University of Wisconsin-Madison and the Center for Magnetic Self-Organization in Laboratory and Astrophysical Plasmas, Madison, Wisconsin (United States)
  2. University of California Los Angeles, Los Angeles, California (United States)
Publication Date:
OSTI Identifier:
22308284
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1612; Journal Issue: 1; Conference: International conference on fusion reactor diagnostics, Varenna (Italy), 9-13 Sep 2013; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; APPROXIMATIONS; CORRECTIONS; CURRENTS; ECR HEATING; ELECTRON TEMPERATURE; ELECTRONS; INTERFEROMETERS; ITER TOKAMAK; PLASMA; POLARIMETERS; POLARIZATION; RELATIVISTIC RANGE; THOMSON SCATTERING