TY - JOUR
T1 - Observation of magnetic islands in tokamak plasmas during the suppression of edge-localized modes
AU - The ASDEX Upgrade Team
AU - Willensdorfer, Matthias
AU - Mitterauer, Verena
AU - Hoelzl, Matthias
AU - Suttrop, Wolfgang
AU - Cianciosa, Mark
AU - Dunne, Mike
AU - Fischer, Rainer
AU - Leuthold, Nils
AU - Puchmayr, Jonas
AU - Samoylov, Oleg
AU - Suárez López, Guillermo
AU - Wendler, Daniel
AU - Zoletnik, S.
AU - Zohm, H.
AU - Zito, A.
AU - Zimmermann, B.
AU - Zilker, M.
AU - Zholobenko, W.
AU - Zhang, W.
AU - Zehetbauer, T.
AU - Zammuto, I.
AU - Zagorski, R.
AU - Yu, Q.
AU - Yoo, C.
AU - Yang, Q.
AU - Wolfrum, E.
AU - Wolf, R.
AU - Wischmeier, M.
AU - Wiringer, B.
AU - Willensdorfer, M.
AU - White, A. E.
AU - Wendler, D.
AU - Weiland, M.
AU - Wang, X.
AU - Wagner, D.
AU - von Toussaint, U.
AU - Voitsekhovitch, I.
AU - Vogel, G.
AU - Viezzer, E.
AU - Vierle, T.
AU - Vicente, J.
AU - Vianello, N.
AU - Verdoolaege, G.
AU - Verdier, T.
AU - Tripský, M.
AU - Maquet, V.
AU - Lyssoivan, A.
AU - Lerche, E.
AU - Kazakov, Y.
AU - Jachmich, S.
N1 - Publisher Copyright:
© The Author(s) 2024.
PY - 2024/12
Y1 - 2024/12
N2 - In tokamaks, a leading platform for fusion energy, periodic filamentary plasma eruptions known as edge-localized modes occur in plasmas with high-energy confinement and steep pressure profiles at the plasma edge. These edge-localized modes could damage the tokamak wall but can be suppressed using small three-dimensional magnetic perturbations. Here we demonstrate that these magnetic perturbations can change the magnetic topology just inside the steep gradient region of the plasma edge. We identify signatures of a magnetic island, and their observation is linked to the suppression of edge-localized modes. We compare high-resolution measurements of perturbed magnetic surfaces with predictions from ideal magnetohydrodynamic theory where the magnetic topology is preserved. Although ideal magnetohydrodynamics adequately describes the measurements in plasmas exhibiting edge-localized modes, it proves insufficient for plasmas where these modes are suppressed. Nonlinear resistive magnetohydrodynamic modelling supports this observation. Our study experimentally confirms the predicted role of magnetic islands in inhibiting the occurrence of edge-localized modes. This will be beneficial for physics-based predictions in future fusion devices to control these modes.
AB - In tokamaks, a leading platform for fusion energy, periodic filamentary plasma eruptions known as edge-localized modes occur in plasmas with high-energy confinement and steep pressure profiles at the plasma edge. These edge-localized modes could damage the tokamak wall but can be suppressed using small three-dimensional magnetic perturbations. Here we demonstrate that these magnetic perturbations can change the magnetic topology just inside the steep gradient region of the plasma edge. We identify signatures of a magnetic island, and their observation is linked to the suppression of edge-localized modes. We compare high-resolution measurements of perturbed magnetic surfaces with predictions from ideal magnetohydrodynamic theory where the magnetic topology is preserved. Although ideal magnetohydrodynamics adequately describes the measurements in plasmas exhibiting edge-localized modes, it proves insufficient for plasmas where these modes are suppressed. Nonlinear resistive magnetohydrodynamic modelling supports this observation. Our study experimentally confirms the predicted role of magnetic islands in inhibiting the occurrence of edge-localized modes. This will be beneficial for physics-based predictions in future fusion devices to control these modes.
UR - http://www.scopus.com/inward/record.url?scp=85207382514&partnerID=8YFLogxK
U2 - 10.1038/s41567-024-02666-y
DO - 10.1038/s41567-024-02666-y
M3 - Article
AN - SCOPUS:85207382514
SN - 1745-2473
VL - 20
SP - 1980
EP - 1988
JO - Nature Physics
JF - Nature Physics
IS - 12
ER -