Effect of Faraday mirror imperfections in a fiber optic current sensor dedicated to ITER

Research output: Contribution to journalArticle


Institutes & Expert groups

  • İzmir Institute of Technology
  • UMons - University of Mons-Hainaut
  • CEA Cadarache - Commissariat à l'Énergie Atomique

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Plasma current measurements in ITER are safety-related and must therefore satisfy a very demanding specification. In this paper, the use of the Fiber Optics Current Sensor (FOCS) operating in the reflection mode with a Faraday mirror to perform plasma current measurements is analyzed. Based on the Jones matrix formalism, we performed numerical simulations to investigate the impact of the Faraday mirror detuning on the measurement accuracy. We show that the use of standard commercial components does not allow to satisfy the ITER requirements for the whole plasma current range. A simple solution to the problem is proposed, which consists in taking into account a mirror calibration in the current estimator. We show that the achievable mirror calibration accuracy is sufficient to fulfill the ITER requirements.


Original languageEnglish
Pages (from-to)48-52
Number of pages5
JournalFusion Engineering & Design
Publication statusPublished - Jan 2019


  • Fiber optics current sensors, Polarimetric sensors, Plasma diagnosis

ID: 6743226