Characteristics of grassy ELMs and their impact on the divertor heat flux width

doi:10.1088/1741-4326/ac83d9

	Characteristics of grassy ELMs and their impact on the divertor heat flux width
	Li, Nami 2,3; Xu, X. Q.3; Wang, Y. F.1; Yan, N.1; Zhang, J. Y.1; Qian, J. P.1; Sun, J. Z.2; Wang, D. Z.2
刊名	NUCLEAR FUSION
	2022-09-01
卷号	62
关键词	grassy ELM BOUT plus plus turbulence heat flux width
ISSN号	0029-5515
DOI	10.1088/1741-4326/ac83d9
通讯作者	Li, Nami(li55@llnl.gov)
英文摘要	BOUT++ turbulence simulations are conducted for a 60 s steady-state long pulse high beta (p) EAST grassy ELM discharge. BOUT++ linear simulations show that the unstable mode spectrum covers a range of toroidal mode numbers from low-n (n = 10-15) peeling-ballooning modes (P-B) to high-n (n = 40-80) drift-Alfven instabilities. Nonlinear simulations show that the ELM crash is triggered by low-n peeling modes and fluctuation is generated at the peak pressure gradient position and radially spread outward into the scrape-off-layer, even though the drift-Alfven instabilities dominate the linear growth phase. However, drift-Alfven turbulence delays the onset of the grassy ELM and enhances the energy loss with the fluctuation extending to pedestal top region. Simulations further show that if the peeling drive is removed, the fluctuation amplitude drops by an order of magnitude and the ELM crashes disappear. The divertor heat flux width is similar to 2 times larger than the estimates based on the HD model and the Eich's ITPA multi-tokamak scaling (or empirical Eich scaling) due to the strong radial turbulence transport.
资助项目	National Key R&D Program of China[2017YFE0301206] ; National Key R&D Program of China[2017YFE0300402] ; National Key R&D Program of China[2017YFE0301100] ; Users with Excellence Program of Hefei Science Center, CAS[2021HSC-UE014] ; National Natural Science Foundation of China[11675037] ; US Department of Energy by Lawrence Livermore National Laboratory[DE-AC52-07NA27344] ; US Department of Energy by Lawrence Livermore National Laboratory[LLNL-JRNL-833914]
WOS研究方向	Physics
语种	英语
出版者	IOP Publishing Ltd
WOS记录号	WOS:000840498400001
资助机构	National Key R&D Program of China ; Users with Excellence Program of Hefei Science Center, CAS ; National Natural Science Foundation of China ; US Department of Energy by Lawrence Livermore National Laboratory
内容类型	期刊论文
源URL	[http://ir.hfcas.ac.cn:8080/handle/334002/132079]
专题	中国科学院合肥物质科学研究院
通讯作者	Li, Nami
作者单位	1.Chinese Acad Sci, Inst Plasma Phys, Hefei 230031, Peoples R China 2.Dalian Univ Technol, Sch Phys, Dalian 116024, Peoples R China 3.Lawrence Livermore Natl Lab, Livermore, CA 94550 USA
推荐引用方式 GB/T 7714	Li, Nami,Xu, X. Q.,Wang, Y. F.,et al. Characteristics of grassy ELMs and their impact on the divertor heat flux width[J]. NUCLEAR FUSION,2022,62.
APA	Li, Nami.,Xu, X. Q..,Wang, Y. F..,Yan, N..,Zhang, J. Y..,...&Wang, D. Z..(2022).Characteristics of grassy ELMs and their impact on the divertor heat flux width.NUCLEAR FUSION,62.
MLA	Li, Nami,et al."Characteristics of grassy ELMs and their impact on the divertor heat flux width".NUCLEAR FUSION 62(2022).