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Title: Chaotic coordinates for the Large Helical Device

Abstract

The theory of quadratic-flux-minimizing (QFM) surfaces is reviewed, and numerical techniques that allow high-order QFM surfaces to be efficiently constructed for experimentally relevant, non-integrable magnetic fields are described. As a practical example, the chaotic edge of the magnetic field in the Large Helical Device (LHD) is examined. A precise technique for finding the boundary surface is implemented, the hierarchy of partial barriers associated with the near-critical cantori is constructed, and a coordinate system, which we call chaotic coordinates, that is based on a selection of QFM surfaces is constructed that simplifies the description of the magnetic field, so that flux surfaces become “straight” and islands become “square.”.

Authors:
 [1]
  1. National Institute for Natural Sciences, National Institute for Fusion Sciences, 322-6 Oroshi, Toki, 509-5292 (Japan)
Publication Date:
OSTI Identifier:
22299676
Resource Type:
Journal Article
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 21; Journal Issue: 10; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1070-664X
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; CHAOS THEORY; COORDINATES; LHD DEVICE; MAGNETIC FIELDS; MAGNETIC SURFACES

Citation Formats

Hudson, S. R., E-mail: shudson@pppl.gov, and Suzuki, Y. Chaotic coordinates for the Large Helical Device. United States: N. p., 2014. Web. doi:10.1063/1.4897390.
Hudson, S. R., E-mail: shudson@pppl.gov, & Suzuki, Y. Chaotic coordinates for the Large Helical Device. United States. https://doi.org/10.1063/1.4897390
Hudson, S. R., E-mail: shudson@pppl.gov, and Suzuki, Y. 2014. "Chaotic coordinates for the Large Helical Device". United States. https://doi.org/10.1063/1.4897390.
@article{osti_22299676,
title = {Chaotic coordinates for the Large Helical Device},
author = {Hudson, S. R., E-mail: shudson@pppl.gov and Suzuki, Y.},
abstractNote = {The theory of quadratic-flux-minimizing (QFM) surfaces is reviewed, and numerical techniques that allow high-order QFM surfaces to be efficiently constructed for experimentally relevant, non-integrable magnetic fields are described. As a practical example, the chaotic edge of the magnetic field in the Large Helical Device (LHD) is examined. A precise technique for finding the boundary surface is implemented, the hierarchy of partial barriers associated with the near-critical cantori is constructed, and a coordinate system, which we call chaotic coordinates, that is based on a selection of QFM surfaces is constructed that simplifies the description of the magnetic field, so that flux surfaces become “straight” and islands become “square.”.},
doi = {10.1063/1.4897390},
url = {https://www.osti.gov/biblio/22299676}, journal = {Physics of Plasmas},
issn = {1070-664X},
number = 10,
volume = 21,
place = {United States},
year = {Wed Oct 15 00:00:00 EDT 2014},
month = {Wed Oct 15 00:00:00 EDT 2014}
}