Theoretical Assessment of Plasma Current Measurement in Tokamaks in Relation with the OTDR Detector Noise

Ratislav Motuz, E. Gescheidtova, Willem Leysen, P.J. Moreau, Andrei Goussarov, Petr Drexler, Marc Wuilpart

    Research outputpeer-review


    In this paper, we present a theoretical analysis of the plasma current measurement in tokamak-type fusion reactors using a Polarization Optical Time-Domain Reflectometer (POTDR) setup, where the general case of non-uniform distribution of a magnetic field along the sensing fibre is analyzed. A low birefringent fibre has been considered as the sensing fibre. The numerical simulations were based on the Jones formalism and take into account the OTDR detector noise reflecting the measurement error as a function of the plasma current. The measurement performance was evaluated for an ITER (International Thermonuclear Experimental Reactor)-relevant sensor configuration. Based on the simulation results we demonstrate that for plasma currents in the range of 0 to 1 MA, the signal-to-noise ratio (SNR) of 6 dB, achievable in modern POTDRs, complies with the ITER requirements. Subsequently, the SNR level of 4 dB satisfies the plasma current range of 1 to 20 MA.
    Original languageEnglish
    Title of host publication2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring)
    PublisherIEEE - Institute of Electrical and Electronics Engineers
    Number of pages5
    ISBN (Print)978-1-7281-3403-1
    StatePublished - 2 Mar 2020
    Event2019 - PhotonIcs & Electromagnetics Research Symposium: Spring (PIERS — SPRING) - University of Rome 'La Sapienza', Rome
    Duration: 17 Jun 201920 Jun 2019


    Conference2019 - PhotonIcs & Electromagnetics Research Symposium
    Internet address

    Cite this