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P: Fachverband Plasmaphysik
P 9: HEPP III
P 9.3: Talk
Tuesday, February 27, 2024, 14:50–15:15, ELP 6: HS 3
Exploring the influence of plasma triangularity on pedestal stability and structure in ASDEX Upgrade — •Lidija Radovanovic1, Elisabeth Wolfrum2, Mike Dunne2, Tobias Görler2, Georg Harrer1, Facundo Sheffield Heit2, Friedrich Aumayr1, and The ASDEX Upgrade Team3 — 1Institute of Applied Physics, TU Wien, 1040 Vienna, Austria — 2Max Planck Institute for Plasma Physics, 85748 Garching, Germany — 3See author list of U. Stroth et al. 2022 Nucl. Fusion 62 042006
The confinement and the performance of a tokamak plasma in the high confinement regime are closely related to the structure of the pedestal. One possible factor limiting the pedestal width is the onset of instabilities, kinetic ballooning modes (KBMs), at the top of the pedestal, which we approximate by local ideal ballooning modes (IBMs). The stability of these modes can be altered by varying the plasma shape. To determine the role of local IBMs at the pedestal top, other possible instabilities present in the pedestal top are analysed with the local linear version of the gyro kinetic code GENE and compared with the shearing rate. The results show that different physical mechanisms influence the pedestal width of the electrons and ions with respect to their density and temperature. Particularly, the electron pressure pedestal top strongly correlates with the minimum in ballooning stability. The objective of this study is to link physical processes in frameworks of MHD, transport and gyro kinetics with the experimentally observed pedestal structure.
Keywords: plasma physics; pedestal; MHD; H-Mode; fusion