https://doi.org/10.1051/epjconf/201817002009
Measurement of plasma current in Tokamaks using an optical fibre reflectometry technique
Department of Electromagnetism and Telecommunications, University of Mons, Mons, Belgium
Belgian Nuclear Research Center SCK-CEN, Mol, Belgium.
CEA (IRFM), Saint-Paul-lez-Durance, France.
e-mail: marc.wuilpart@umons.ac.be
Published online: 10 January 2018
An optical time-domain reflectometer sensitive to the polarization of light is proposed for the measurement of plasma current in the Tore Supra fusion reactor. The measurement principle relies on the Faraday effect i.e. on the generation of a circular birefringence along an optical fiber subject to an axial magnetic field. The circular birefringence induces a polarization rotation that can be mapped along the fiber thanks to an opticaltime domain reflectometer followed by an linear polarizer. A proper fitting of the measurement trace then allows determining the applied plasma current. The sensor has been experimentally validated on the Tore Supra tokamak fusion reactor for a plasma current range going from 0.6 to 1.5 MA. A maximum error of 13.50% has been observed for the lowest current.
Key words: Optical time-domain reflectometry / Faraday effect / current sensing / polarimetry
© The Authors, published by EDP Sciences, 2018
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (http://creativecommons.org/licenses/by/4.0/).
