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Tracking Blobs with Machine Learning in the Turbulent Edge Plasma of a Tokamak

ORAL

Abstract

The analysis of turbulence in plasmas is fundamental in fusion research. Experimental studies are challenging due to the diverse processes that drive the high-speed dynamics of turbulent phenomena. This work presents a novel application of motion tracking to identify and track turbulent filaments in fusion plasmas, called blobs, in high-frequency video data obtained from Gas Puff Imaging diagnostics. We compare four baseline methods trained on synthetic data and then test on synthetic and real data obtained from plasmas in the Tokamak à Configuration Variable. From the size of the blobs estimated from each of the baseline methods employed, we identify the regime of the blob dynamics as described in Myra et al. [1] which agrees with state-of-the-art conditional averaging methods. As an on-going analysis, we use our blob-tracking models to compare 1) a low- and a high-density plasma, as well as 2) a negative and a positive triangularity plasma, extending our study in [2], in order to find any differences in underlying characteristics of edge fluctuations.

[1] J. R. Myra et al 2006 Phys. Plasmas 13, 112502

[2] W. Han et al 2021 Nucl. Fusion 61 034003

Publication: W. Han, N. Offeddu, T. Golfinopoulos, C. Theiler, C.K. Tsui, J.A. Boedo, E.S. Marmar, and the TCV team. Suppression of first-wall interaction in negative triangularity plasmas on TCV. 2021 Nucl. Fusion 61 034003.<br>W. Han, R. A. Pietersen, R. Villamor-Lora, M. Beveridge, N. Offeddu, T. Golfinopoulos, C. Theiler, J. L. Terry, E. S. Marmar, and I. Drori, "Tracking blobs in the turbulent edge plasma of a tokamak fusion device," (2021). https://arxiv.org/abs/2111.08570

Presenters

  • Woonghee Han

    Massachusetts Institute of Technology MI, Massachusetts Institute of Technology MIT

Authors

  • Woonghee Han

    Massachusetts Institute of Technology MI, Massachusetts Institute of Technology MIT

  • Randall A Pietersen

    Massachusetts Institute of Technology MIT

  • Rafael Villamor-Lora

    Massachusetts Institute of Technology MIT

  • Matthew Beveridge

    Massachusetts Institute of Technology MIT

  • Nicola Offeddu

    Ecole Polytechnique Federale de Lausanne, École Polytechnique Fédérale de Lausanne

  • Sajidah Ahmed

    UiT - The Arctic University of Norway

  • Gregor Decristoforo

    UiT The Arctic University of Norway, UiT - The Arctic University of Norway

  • Theodore Golfinopoulos

    Massachusetts Institute of Technology, Massachusetts Institute of Technology MI, Massachusetts Institute of Technology MIT

  • Christian Theiler

    Ecole Polytechnique Federale de Lausanne, École Polytechnique Fédérale de Lausanne

  • James L Terry

    MIT PSFC, Massachusetts Institute of Technology MI, MIT-PSFC, MIT Plasma Science Fusion Center, Massachusetts Institute of Technology MIT

  • Earl S Marmar

    Massachusetts Institute of Technology MIT

  • Iddo Drori

    Massachusetts Institute of Technology MIT