Theoretical assessment of the OTDR detector noise on plasma current measurement in tokamaks

Research output: Contribution to journalArticlepeer-review


Institutes & Expert groups

  • Masaryk University - Department of Geological Sciences, Faculty of Science
  • UMons - University of Mons-Hainaut

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In this paper, we propose a theoretical study dedicated to the assessment of plasma current measurement in magnetic confinement fusion reactors using a polarization optical time-domain reflectometer (POTDR) setup with a low-birefringence fiber used as the sensing fiber. We consider the general case of a non-uniform magnetic-field distribution along the sensing fiber. The numerical simulations, based on Jones formalism taking into account the OTDR noise, provide the measurement error as a function of the plasma current. The measurement performance is evaluated for an ITER-relevant sensor configuration. We demonstrate that a signal-to-noise ratio of 6 dB, achievable in modern POTDRs, allows us to comply with the ITER requirements for plasma currents from 0 to 1 MA, while for the 1 to 20 MA range, the level is relaxed to 4 dB.


Original languageEnglish
Pages (from-to)2795-2802
Number of pages8
JournalApplied Optics
Issue number11
Publication statusPublished - 10 Apr 2019


  • OTDR, Tokamaks

ID: 6743564