Comparison of dynamical features between the fast H-L and the H-I-L transition for EAST RF-heated plasmas

doi:10.1088/1402-4896/ac4635

	Comparison of dynamical features between the fast H-L and the H-I-L transition for EAST RF-heated plasmas
	Chen, Liang 1; Xu, Guosheng 1,5; Shao, Lingming 1; Gao, Wei 1; Wang, Yifeng 1; Duan, Yanmin 1; Wang, Shouxin 1; Ti, Ang 1; Mao, Songtao 1; Li, Miaohui 1
刊名	PHYSICA SCRIPTA
	2022
卷号	97
关键词	H-L transition I-phase mean E x B flow diamagnetic flows divertor recycling
ISSN号	0031-8949
DOI	10.1088/1402-4896/ac4635
通讯作者	Xu, Guosheng(gsxu@ipp.ac.cn) ; Shao, Lingming(shaolm@ipp.ac.cn)
英文摘要	In this paper, a comparison of dynamical features between the fast H-L and the H-I-L transition, which can be identified by the intermediate phase, or 'I-phase', has been made for radio-frequency (RF) heated deuterium plasmas in EAST. The fast H-L transition is characterized by a rapid release of stored energy during the transition transient, while the H-I-L transition exhibits a 'soft' H-mode termination. One important distinction between the transitions has been observed by dedicated probe measurements slightly inside the separatrix, with respect to the radial gradient of the floating potential, which corresponds to the E x B flow and/or the electron temperature gradient. The potential gradient inside the separatrix oscillates and persists during the stationary I-phase, and shows a larger amplitude than that before the fast H-L transition. The reduction of the gradient leads to the final transition to the L-mode for both the fast H-L and the H-I-L transition. These findings indicate that the mean E x B flow shear and/or edge electron temperature gradient play a critical role underlying the H-L transition physics. In addition, the back transition in EAST is found to be sensitive to magnetic configuration, where the vertical configuration, i.e., inner strike-point located at vertical target, favours access to the H-I-L transition, while the horizontal shape facilitates achievement of the fast H-L transition. The divertor recycling level normalized to electron density is higher before the fast H-L transition, as compared to that before the I-phase, which strongly suggest that the density of the recycled neutrals is an important ingredient in determining the back transition behaviour.
资助项目	National Magnetic Confinement Fusion Science Program of China[2019YFE03030000] ; National Natural Science Foundation of China[U19A20113] ; National Natural Science Foundation of China[1197050784] ; Science Foundation of Institute of Plasma Physics, Chinese Academy of Sciences[DSJJ-18-02] ; AHNSF[1808085J07] ; CASHIPS Director's Fund[BJPY2019A01] ; CASHIPS Director's Fund[YZJJ2020QN13]
WOS关键词	HIGH-CONFINEMENT ; MODE ; TURBULENCE
WOS研究方向	Physics
语种	英语
出版者	IOP Publishing Ltd
WOS记录号	WOS:000740834700001
资助机构	National Magnetic Confinement Fusion Science Program of China ; National Natural Science Foundation of China ; Science Foundation of Institute of Plasma Physics, Chinese Academy of Sciences ; AHNSF ; CASHIPS Director's Fund
内容类型	期刊论文
源URL	[http://ir.hfcas.ac.cn:8080/handle/334002/127109]
专题	中国科学院合肥物质科学研究院
通讯作者	Xu, Guosheng; Shao, Lingming
作者单位	1.Chinese Acad Sci, Inst Plasma Phys, Hefei Inst Phys Sci, Hefei 230031, Peoples R China 2.Dalian Univ Technol, Sch Phys & Optoelect Technol, Dalian 116024, Peoples R China 3.Tech Univ Denmark, Dept Phys, DK-2800 Lyngby, Denmark 4.Anhui Univ Sci & Technol, Sch Mech Engn, Huainan 232001, Peoples R China 5.Univ Sci & Technol China, Hefei 230026, Peoples R China
推荐引用方式 GB/T 7714	Chen, Liang,Xu, Guosheng,Shao, Lingming,et al. Comparison of dynamical features between the fast H-L and the H-I-L transition for EAST RF-heated plasmas[J]. PHYSICA SCRIPTA,2022,97.
APA	Chen, Liang.,Xu, Guosheng.,Shao, Lingming.,Gao, Wei.,Wang, Yifeng.,...&Gong, Xianzu.(2022).Comparison of dynamical features between the fast H-L and the H-I-L transition for EAST RF-heated plasmas.PHYSICA SCRIPTA,97.
MLA	Chen, Liang,et al."Comparison of dynamical features between the fast H-L and the H-I-L transition for EAST RF-heated plasmas".PHYSICA SCRIPTA 97(2022).