Title: Toward holistic understanding of the ITER-like resonant magnetic perturbation (RMP) ELM control on KSTAR

Abstract

Here, KSTAR has clarified a set of unresolved 3D physics issues utilizing the ITER-like in-vessel, three-row, resonant magnetic perturbation (RMP) configurations. Since RMP-driven, edge-localized-modes (ELMs)-crash control elevates the divertor heat flux peak through its impact on edge plasma parameters and transport, a series of intentionally misaligned RMP configurations (IMCs) have been explored to investigate the relationship between RMP ELM control and divertor heat fluxes, while searching for an ideal IMC that could be favorable in both aspects. First of all, the contrasting influence of kink vs anti-kink phasing on the ELM-crash suppression has been articulated, demonstrating the synergistic benefit of 'kink' phasing on ELM-crash-suppression. On the other hand, the three-row IMC in the anti-kink phasing becomes more insensitive to the ELM-crashes at the sub-marginal level of RMP, consistent with theory. Meanwhile, the divertor 'wetted' area of ELM-crash-suppression gets narrower than that of ELM-crash-mitigation, suggesting that ELM-crash-mitigation remains advantageous over ELM-crash-suppression in terms of time-averaged divertor thermal loading. In comparison, based on a set of two-row IMCs, no evidence of divertor heat flux broadening was found during ELM-crash-suppression, supporting a hypothesis that the dispersal of the divertor heat flux in three-row IMCs cannot be driven by helically structured two-row RMPs alone.more » Among ITER-like three-rows, lower two-row RMPs have been found to be much more effective in suppressing the ELM-crashes than upper two-row RMPs. Although it is quite preliminary, the up/down asymmetric dependence of RMP coupling may be generically attributed to lower-single-null plasmas. Such a holistic understanding of RMP-driven, ELM-crash-control in KSTAR is expected not only to elucidate various subtle points in the vicinity of ELM-crash-suppression, but also to clarify the relevant divertor thermal loading issues for ITER and beyond.« less

Authors:

In, Yongkyoon  ^[1];

• Search DOE PAGES for author "In, Yongkyoon"
• Search DOE PAGES for ORCID "0000-0002-9219-1304"

Lee, H. H. ^[2]; Park, G. Y. ^[2]; Jeon, Y. M. ^[2]; Kim, M.  ^[2];

• Search DOE PAGES for author "Kim, M."
• Search DOE PAGES for ORCID "0000-0002-8627-4584"

Kim, K. ^[2]; Park, J. -K.  ^[3];

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• Search DOE PAGES for ORCID "0000-0003-2419-8667"

Yang, S. M.  ^[3];

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• Search DOE PAGES for ORCID "0000-0003-1214-1268"

Loarte, A.  ^[4];

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• Search DOE PAGES for ORCID "0000-0001-9592-1117"

Liu, Y. Q.  ^[5];

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• Search DOE PAGES for ORCID "0000-0002-8192-8411"

Park, H. ^[1]

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+ Show Author Affiliations

1. Ulsan National Inst. of Science and Technology, (Korea, Republic of)
2. Korea Inst. of Fusion Energy, Daejeon (Korea, Republic of)
3. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
4. ITER Organization, St. Paul Lez Durance (France)
5. General Atomics, San Diego, CA (United States)

Publication Date:

Tue Apr 05 00:00:00 EDT 2022

Research Org.:

Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

Sponsoring Org.:

USDOE; Korean Ministry of Science and ICT; National and Research Fund

OSTI Identifier:

1880121

Grant/Contract Number:  

AC02-09CH11466

Resource Type:

Accepted Manuscript

Journal Name:

Nuclear Fusion

Additional Journal Information:

Journal Volume: 62; Journal Issue: 6; Journal ID: ISSN 0029-5515

Publisher:

IOP Science

Country of Publication:

United States

Language:

English

Subject:

70 PLASMA PHYSICS AND FUSION TECHNOLOGY; edge-localized-modes (ELM); resonant magnetic perturbation (RMP); ELM-crash-suppression; divertor thermal loading