Models comparison for JET polarimeter data
- Centro Ricerche Energia Frascati, Euratom-ENEA Association, Frascati (Italy)
- Association EURATOM-UKAEA Culham Science Centre Abingdon 0X14 3DB (UK) (United Kingdom)
- Consorzio RFX, Euratom-ENEA Association, Padova (Italy)
A complete comparison between the theory and the measurements in polarimetry was done by using the Far Infrared Polarimeter at JET. More than 300 shots were analyzed, including a wide spectrum of JET scenarios in all critical conditions for polarimetry: high density, high and very low fields, high temperatures.This work is aimed at the demonstration of the robustness of the theoretical models for the JET polarimeter measurements in the perspective of using these models for ITER like plasma scenarios . In this context, an assessment was performed on how the line-integrated plasma density along the central vertical chord of FIR polarimeter could be evaluated using the Cotton-Mouton effect and its possible concrete use to correct fringe jumps of the interferometer.The models considered are: i) the rigorous numerical solution of the Stokes propagation equations, using dielectric tensor evaluated from JET equilibrium and Thomson scattering [1,2]; ii) two types of approximated solutions [2,3] and iii) the Guenther empirical model [4] that considers the mutual effect between Cotton-Mouton and Faraday rotation angle. The model calculations have been compared with polarimeter measurements for the Cotton-Mouton phase shift.The agreement with theory is satisfactory within the limits of experimental errors [3].
- OSTI ID:
- 21136757
- Journal Information:
- AIP Conference Proceedings, Vol. 988, Issue 1; Conference: International conference on burning plasma diagnostics, Varenna (Italy), 24-28 Sep 2007; Other Information: DOI: 10.1063/1.2905056; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA). EFDA-JET Contributors; ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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