On the causes of anomaly in the polarimetric measurements at JET

Enrico Zilli, Matteo Brombin, Alexandru Boboc, Andrea Murari

Research output: Contribution to journalArticle

Abstract

A recent investigation of an anomaly in the polarimetric measurements at the Joint European Torus (JET) is reported. A calculation, based on the Stokes vector and the Mueller matrix method, has been developed to simulate the effects of the waveguide on the polarization of the propagating beams. These effects consist in both rotations of the polarization and alterations of the ellipticity, and affect both the probing and the reference beams. The model that is assumed here is made up of a rotated retarder followed by a rotator, with three free parameters to be optimized. A very good agreement between the resulting calculated curves and the experimental calibration diagrams is obtained for the four vertical channels of JET polarimeter. Variations of both phase shift and amplitude ratio are fitted by the model. This result supports the hypothesis that the waveguide system, which transfers the beams from the torus to the detectors, is the main source of the anomaly. © 2012 IEEE.
Original languageEnglish
Article number6161656
Pages (from-to)1142 - 1148
Number of pages7
JournalIEEE Transactions on Plasma Science
Volume40
Issue number4
DOIs
Publication statusPublished - Apr 2012
Externally publishedYes

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All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics
  • Nuclear and High Energy Physics

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