Physics design of new lower tungsten divertor for long-pulse high-power operations in EAST

doi:10.1088/1741-4326/ac3297

	Physics design of new lower tungsten divertor for long-pulse high-power operations in EAST
	Xu, G. S.5,6; Wang, L.5; Yao, D. M.5; Jia, G. Z.5; Sang, C. F.7; Liu, X. J.5; Chen, Y. P.5; Si, H.5; Yang, Z. S.5; Guo, H. Y.2,8
刊名	NUCLEAR FUSION
	2021-12-01
卷号	61
关键词	tungsten divertor upgrade closed divertor concept plasma-material interaction divertor detachment EAST tokamak
ISSN号	0029-5515
DOI	10.1088/1741-4326/ac3297
通讯作者	Xu, G. S.(gsxu@ipp.ac.cn) ; Jia, G. Z.(gzjia@ipp.ac.cn)
英文摘要	A new lower tungsten divertor has been developed and installed in the EAST superconducting tokamak to replace the previous graphite divertor with power handling capability increasing from <2 MW m(-2) to similar to 10 MW m(-2), aiming at achieving long-pulse H-mode operations in a full metal wall environment with the steady-state divertor heat flux of similar to 10 MW m(-2). A new divertor concept, 'corner slot' (CS) divertor, has been employed. By using the 'corner effect', a strongly dissipative divertor with the local buildup of high neutral pressure near the corner can be achieved, so that stable detachment can be maintained across the entire outer target plate with a relatively lower impurity seeding rate, at a separatrix density compatible with advanced steady-state core scenarios. These are essential for achieving efficient current drive with low-hybrid waves, a low core impurity concentration and thus a low loop voltage for fully non-inductive long-pulse operations. Compared with the highly closed small-angle-slot divertor in DIII-D, the new divertor in EAST exhibits the following merits: (1) a much simpler geometry with integral cassette body structure, combining vertical and horizontal target plates, which are more suitable for actively water-cooled W/Cu plasma facing components, facilitating installation precision control for minimizing surface misalignment, achieving high engineering reliability and lowering the capital cost as well; (2) it has much greater flexibility in magnetic configurations, allowing for the position of the outer strike point on either vertical or horizontal target plates to accommodate a relatively wide triangularity range, delta (l) = 0.4-0.6, thus enabling to explore various advanced scenarios. A water-cooled copper in-vessel coil has been installed under the dome. Five supersonic molecular beam injection systems have been mounted in the divertor to achieve faster and more precise feedback control of the gas injection rate. Furthermore, this new divertor allows for double null divertor operation and slowly sweeping the outer strike point across the horizontal and vertical target plates to spread the heat flux for long-pulse operations. Preliminary experimental results demonstrate the 'corner effect' and are in good agreement with simulations using SOLPS-ITER code including drifts. The EAST new divertor provides a test-bed for the closed divertor concept to achieve steady-state detachment operation at high power. Next step, a more closed divertor, 'sharp-cornered slot' divertor, building upon the current CS divertor concept, has been proposed as a candidate for the EAST upper divertor upgrade.
资助项目	National Magnetic Confinement Fusion Energy R&D Program of China[2019YFE03030000] ; National Magnetic Confinement Fusion Energy R&D Program of China[2018YFE0303104] ; National Magnetic Confinement Fusion Energy R&D Program of China[2017YFE0301300] ; National Magnetic Confinement Fusion Energy R&D Program of China[2017YFE0300402] ; National Natural Science Foundation of China[U19A20113] ; National Natural Science Foundation of China[11922513] ; Key Research Program of Frontier Sciences, CAS[QYZDB-SSW-SLH001] ; CASHIPS Director's Fund[BJPY2019A01] ; AHNSF[1808085J07]
WOS关键词	DETACHMENT ; IMPLEMENTATION ; OPTIMIZATION ; EXHAUST
WOS研究方向	Physics
语种	英语
出版者	IOP Publishing Ltd
WOS记录号	WOS:000722411300001
资助机构	National Magnetic Confinement Fusion Energy R&D Program of China ; National Natural Science Foundation of China ; Key Research Program of Frontier Sciences, CAS ; CASHIPS Director's Fund ; AHNSF
内容类型	期刊论文
源URL	[http://ir.hfcas.ac.cn:8080/handle/334002/126750]
专题	中国科学院合肥物质科学研究院
通讯作者	Xu, G. S.; Jia, G. Z.
作者单位	1.Gen Atom, POB 85608, San Diego, CA 92186 USA 2.ENN Sci & Technol Dev Co Ltd, Langfang 065001, Peoples R China 3.Southwestern Inst Phys, Box 432, Chengdu 610041, Peoples R China 4.Anhui Univ Sci & Technol, Sch Mech Engn, Huainan 232001, Peoples R China 5.Chinese Acad Sci, Inst Plasma Phys, POB 1126, Hefei 230031, Peoples R China 6.Univ Sci & Technol China, Hefei 230026, Peoples R China 7.Dalian Univ Technol, Dalian 116024, Peoples R China 8.ENN Energy Holdings Ltd, Langfang 065001, Peoples R China
推荐引用方式 GB/T 7714	Xu, G. S.,Wang, L.,Yao, D. M.,et al. Physics design of new lower tungsten divertor for long-pulse high-power operations in EAST[J]. NUCLEAR FUSION,2021,61.
APA	Xu, G. S..,Wang, L..,Yao, D. M..,Jia, G. Z..,Sang, C. F..,...&Wan, B. N..(2021).Physics design of new lower tungsten divertor for long-pulse high-power operations in EAST.NUCLEAR FUSION,61.
MLA	Xu, G. S.,et al."Physics design of new lower tungsten divertor for long-pulse high-power operations in EAST".NUCLEAR FUSION 61(2021).