Mapping the sawtooth

Smiet, C. B.; Kramer, G. J.; Hudson, S. R.

doi:10.1088/1361-6587/ab5073

Title: Mapping the sawtooth

Journal Article · 23 October 2019 · Plasma Physics and Controlled Fusion

DOI: https://doi.org/10.1088/1361-6587/ab5073 · OSTI ID:1580273

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Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Leiden Univ. (Netherlands)
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

The sawtooth oscillation involves a topological change of the magnetic field lines in the core of a tokamak discharge. In this work, we simulate a steady state sawtoothing discharge using the M3DC ¹-code. During the sawtooth the topological structure of the magnetic field is analyzed by tracking the fixed points of the field line map: the mapping induced by the field lines going once around the tokamak. We numerically locate the fixed points of the field line map (of which the magnetic axis is one) and use them construct a Poincaré section that resolves the core region and the (1, 1) island. Finally, by following the evolution of the magnetic field through the motion and bifurcation of the fixed points of the field line map we get an intuitive picture of the processes that take place during a Kadomtsev style sawtooth crash.

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Research Organization:: Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)

Sponsoring Organization:: USDOE Office of Science (SC), Fusion Energy Sciences (FES)

Grant/Contract Number:: AC02-09CH11466

OSTI ID:: 1580273

Journal Information:: Plasma Physics and Controlled Fusion, Vol. 62, Issue 2; ISSN 0741-3335

Publisher:: IOP ScienceCopyright Statement

Country of Publication:: United States

Language:: English

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Cited by: 3 works

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