Tearing mode formation induced by internal crash events at different β N

TitleTearing mode formation induced by internal crash events at different β N
Publication TypeJournal Article
Year of Publication2017
AuthorsV. Igochine, I. Classen, M. Dunne, A. Gude, S. Gunter, K. Lackner, R.M McDermott, M. Sertoli, D.. Vezinet, M. Willensdorfer, Q. Yu, H. Zohm, ASDEX Upgrade Team
JournalNuclear Fusion
Volume57
Issue3
Pagination036015
Abstract

Tearing mode formation after internal crash events like sawteeth or fishbones is one of the most important MHD processes that results in a big island structure and associated confinement degradation. The process implies magnetic reconnection at the rational surface, which has been investigated in great detail in the ASDEX Upgrade tokamak. Using direct local measurements, it is found that the crash leads to the formation of an ideal kink mode with large saturated amplitude at the resonant surface immediately after the sawtooth crash. This kink mode transforms into a tearing mode on a much longer timescale than the crash itself. The ideal kink mode, formed at the resonant surface after the crash, provides the driving force for the magnetic reconnection. The conversion of the ideal kink mode into a tearing mode after the internal crash is similar for various values of plasma rotation and normalized pressure.

URLhttp://pubman.mpdl.mpg.de/pubman/item/escidoc:2398199:6/component/escidoc:2401513/Igochine_Tearing.pdf
DOI10.1088/1741-4326/aa4fb9
Division

FP

Department

PEPD

PIDc6df82450ccb1327528ac6de28bc9dfe
Alternate TitleNucl. Fusion
LabelOA

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