Nonlinear MHD modeling of n = 1 RMP-induced pedestal transport and mode coupling effects on ELM suppression in KSTAR

S. K. Kim, S. Pamela, N. Logan, Y. S. Na, C. Lee, J. K. Park, S. Yang, Q. Hu, M. Becoulet, G. Huijsmans, M. Hoelzl, Y. In, M. W. Kim, H. H. Lee, J. Lee, J. H. Lee, O. Kwon, E. Kolemen

Research output: Contribution to journalArticlepeer-review

8 Scopus citations

Abstract

Fully suppressing edge-localized modes (ELMs), e.g., with resonant magnetic perturbations (RMPs), is essential to reach and sustain high-performance steady-state H-mode plasmas because large ELMs can significantly reduce the lifetime of divertor components in future tokamak reactors. RMP-driven ELM suppression in KSTAR has been modeled by coupling the neoclassical transport code PENTRC to the nonlinear 3D MHD code JOREK. We have found that the radial transport from the combined effects of the kink-peeling, tearing response, and neoclassical toroidal viscosity can explain the pedestal degradation observed in experiments. In addition, it has been found that the RMP response can increase the inter-ELM heat flux on the lower outer divertor by redistributing the heat transport between the divertor plates. In addition to the degraded pedestal, ELM suppression is also attributable to the RMP-induced mode interactions. While the linear stability of peeling-ballooning mode (PBMs) improves owing to the degraded pedestal, the PBM and RMP interaction increases the spectral transfer between edge harmonics, preventing catastrophic growth and the crash of unstable modes. Here, it turns out that the magnetic islands near the pedestal top can play a vital role in mediating the mode interactions.

Original languageEnglish (US)
Article number106021
JournalNuclear Fusion
Volume62
Issue number10
DOIs
StatePublished - Dec 2022

All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics
  • Condensed Matter Physics

Keywords

  • KSTAR
  • RMP
  • edge localized mode
  • mode coupling
  • neoclassical toroidal viscosity
  • nonlinear MHD
  • peeling ballooning mode

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