AIP Advances (Feb 2018)

Effect of time-varying flow-shear on the nonlinear stability of the boundary of magnetized toroidal plasmas

  • Youngmin Oh,
  • Hyung Ju Hwang,
  • Michael Leconte,
  • Minwoo Kim,
  • Gunsu S. Yun

DOI
https://doi.org/10.1063/1.5006554
Journal volume & issue
Vol. 8, no. 2
pp. 025224 – 025224-11

Abstract

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We propose a phenomenological yet general model in a form of extended complex Ginzburg-Landau equation to understand edge-localized modes (ELMs), a class of quasi-periodic fluid instabilities in the boundary of toroidal magnetized high-temperature plasmas. The model reproduces key dynamical features of the ELMs (except the final explosive relaxation stage) observed in the high-confinement state plasmas on the Korea Superconducting Tokamak Advanced Research: quasi-steady states characterized by field-aligned filamentary eigenmodes, transitions between different quasi-steady eigenmodes, and rapid transition to non-modal filamentary structure prior to the relaxation. It is found that the inclusion of time-varying perpendicular sheared flow is crucial for reproducing all of the observed dynamical features.