Optimal MSE polarisation angle and q-profile estimation using Kalman filters and the plasma simulator RAPTOR

EUROfusion MST1 Team, the ASDEX-Upgrade team, M.C.C. Messmer (Corresponding author), F. Felici, O. Sauter, A. A. Teplukhina, J. P.G. Loenen, M. Reich, R. Fischer, D. Rittich, R. J.E. Jaspers

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Uittreksel

Accurate q-profile reconstruction is of importance for the development of advanced scenarios, but continues to be a challenge in tokamak research. To constrain the q-profile in the plasma centre the motional Stark effect diagnostic (MSE) is often used, however achieving routine measurements with the required accuracy proves to be difficult in many devices. We present a novel approach to obtain accurate estimates of the q-profile using an observer based approach. The observer combines MSE measurements with a model-based prediction of the system. For this the plasma transport simulator RAPTOR is coupled with a fixed-boundary equilibrium solver to create a model-based prediction of the MSE measurements. An extended Kalman filter is used to merge profile evolution predictions from the RAPTOR code with measurements. Using synthetic data we demonstrate accurate q-profile estimations in situations where the model is purposely disturbed and only erroneous MSE measurements are available. For shots at ASDEX Upgrade we show that by constraining RAPTOR with MSE measurements, the evolution of the model's q-profile is in close proximity to reference profiles of reconstructed equilibria from an integrated diagnostic suite.

TaalEngels
Artikelnummer035011
Aantal pagina's11
TijdschriftPlasma Physics and Controlled Fusion
Volume61
Nummer van het tijdschrift3
DOI's
StatusGepubliceerd - 1 feb 2019

Vingerafdruk

Stark effect
Kalman filters
simulators
Simulators
Polarization
Plasmas
polarization
profiles
predictions
Extended Kalman filters
shot
proximity
estimates

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    Citeer dit

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    title = "Optimal MSE polarisation angle and q-profile estimation using Kalman filters and the plasma simulator RAPTOR",
    abstract = "Accurate q-profile reconstruction is of importance for the development of advanced scenarios, but continues to be a challenge in tokamak research. To constrain the q-profile in the plasma centre the motional Stark effect diagnostic (MSE) is often used, however achieving routine measurements with the required accuracy proves to be difficult in many devices. We present a novel approach to obtain accurate estimates of the q-profile using an observer based approach. The observer combines MSE measurements with a model-based prediction of the system. For this the plasma transport simulator RAPTOR is coupled with a fixed-boundary equilibrium solver to create a model-based prediction of the MSE measurements. An extended Kalman filter is used to merge profile evolution predictions from the RAPTOR code with measurements. Using synthetic data we demonstrate accurate q-profile estimations in situations where the model is purposely disturbed and only erroneous MSE measurements are available. For shots at ASDEX Upgrade we show that by constraining RAPTOR with MSE measurements, the evolution of the model's q-profile is in close proximity to reference profiles of reconstructed equilibria from an integrated diagnostic suite.",
    keywords = "extended Kalman filter, motional Stark effect, MSE, observer, q-profile reconstruction, RAPTOR, tokamak control",
    author = "{EUROfusion MST1 Team} and {ASDEX-Upgrade team} and M.C.C. Messmer and F. Felici and O. Sauter and Teplukhina, {A. A.} and Loenen, {J. P.G.} and M. Reich and R. Fischer and D. Rittich and Jaspers, {R. J.E.}",
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    doi = "10.1088/1361-6587/aaf7ed",
    language = "English",
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    journal = "Plasma Physics and Controlled Fusion",
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    Optimal MSE polarisation angle and q-profile estimation using Kalman filters and the plasma simulator RAPTOR. / EUROfusion MST1 Team; the ASDEX-Upgrade team ; Messmer, M.C.C. (Corresponding author).

    In: Plasma Physics and Controlled Fusion, Vol. 61, Nr. 3, 035011, 01.02.2019.

    Onderzoeksoutput: Bijdrage aan tijdschriftTijdschriftartikelAcademicpeer review

    TY - JOUR

    T1 - Optimal MSE polarisation angle and q-profile estimation using Kalman filters and the plasma simulator RAPTOR

    AU - EUROfusion MST1 Team

    AU - ASDEX-Upgrade team

    AU - Messmer,M.C.C.

    AU - Felici,F.

    AU - Sauter,O.

    AU - Teplukhina,A. A.

    AU - Loenen,J. P.G.

    AU - Reich,M.

    AU - Fischer,R.

    AU - Rittich,D.

    AU - Jaspers,R. J.E.

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    N2 - Accurate q-profile reconstruction is of importance for the development of advanced scenarios, but continues to be a challenge in tokamak research. To constrain the q-profile in the plasma centre the motional Stark effect diagnostic (MSE) is often used, however achieving routine measurements with the required accuracy proves to be difficult in many devices. We present a novel approach to obtain accurate estimates of the q-profile using an observer based approach. The observer combines MSE measurements with a model-based prediction of the system. For this the plasma transport simulator RAPTOR is coupled with a fixed-boundary equilibrium solver to create a model-based prediction of the MSE measurements. An extended Kalman filter is used to merge profile evolution predictions from the RAPTOR code with measurements. Using synthetic data we demonstrate accurate q-profile estimations in situations where the model is purposely disturbed and only erroneous MSE measurements are available. For shots at ASDEX Upgrade we show that by constraining RAPTOR with MSE measurements, the evolution of the model's q-profile is in close proximity to reference profiles of reconstructed equilibria from an integrated diagnostic suite.

    AB - Accurate q-profile reconstruction is of importance for the development of advanced scenarios, but continues to be a challenge in tokamak research. To constrain the q-profile in the plasma centre the motional Stark effect diagnostic (MSE) is often used, however achieving routine measurements with the required accuracy proves to be difficult in many devices. We present a novel approach to obtain accurate estimates of the q-profile using an observer based approach. The observer combines MSE measurements with a model-based prediction of the system. For this the plasma transport simulator RAPTOR is coupled with a fixed-boundary equilibrium solver to create a model-based prediction of the MSE measurements. An extended Kalman filter is used to merge profile evolution predictions from the RAPTOR code with measurements. Using synthetic data we demonstrate accurate q-profile estimations in situations where the model is purposely disturbed and only erroneous MSE measurements are available. For shots at ASDEX Upgrade we show that by constraining RAPTOR with MSE measurements, the evolution of the model's q-profile is in close proximity to reference profiles of reconstructed equilibria from an integrated diagnostic suite.

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    KW - MSE

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    KW - RAPTOR

    KW - tokamak control

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