Impact of lithium wall conditioning and wave-frequency on high density lower hybrid current drive experiment on EAST

doi:10.1016/j.nme.2021.100955

	Impact of lithium wall conditioning and wave-frequency on high density lower hybrid current drive experiment on EAST
	Baek, S. G.1; Li, M. H.3; Wallace, G. M.1; Bonoli, P. T.1; Choi, W.2; Ding, B. J.3; Gao, W.3; Gong, X.3; Li, Y. C.3; Lin, S.3
刊名	NUCLEAR MATERIALS AND ENERGY
	2021-03-01
卷号	26
关键词	Lower hybrid current drive Scrape-off-layer Divertor D-alpha Tokamak Lithium wall conditioning
DOI	10.1016/j.nme.2021.100955
通讯作者	Baek, S. G.(sgbaek@psfc.mit.edu) ; Li, M. H.(mhli@ipp.ac.cn) ; Ding, B. J.(bjding@ipp.ac.cn)
英文摘要	A series of dedicated lower hybrid current drive (LHCD) experiments on EAST shows that lithium wall conditioning extends LH current drive and heating up to the line-averaged density of (n) over bar (e) approximate to 4x10(19) m(-3) for both 2.45 and 4.6 GHz. Current drive at such a high density is crucial for the development of long-pulse non-inductive scenarios on EAST. With lithiation, the LH power injection of 1.5 MW at 2.45 GHz resulted in a drop of loop voltage of similar to 0.3 V, which is a comparable loop voltage drop observed with 1.1 MW at 4.6 GHz. The observed decrease in loop voltage is attributed mostly to the RF heating effect. Another LHCD experiment suggests that lithium wall coating has a more significant impact on the scrape-off-layer (SOL) properties than changes in the Greenwald fraction. LHCD at 2.45 GHz still suffers from a loss of efficiency. Enhanced power ionization in front of the launcher may cause the onset of density-dependent wave instabilities. The rise in the midplane SOL density may also accelerate a transition in the divertor regime, leading to additional ionization and collisional losses in the X-point divertor plasma. Ray-tracing modeling supports that a lower wave frequency is more prone to collisional power loss. The experiments confirm that lithiation is a useful tool to control the SOL plasma, and suggest that density control in front of the launcher may be critical to mitigating power loss mechanisms in the plasma boundary.
资助项目	US Department of Energy[DE-SC0010492] ; National Key Research and Development Program of China[2016YFA0400603] ; National Key Research and Development Program of China[2016YFA0400602] ; National Natural Science Foundation of China[11775259] ; National Natural Science Foundation of China[11675214] ; National Natural Science Foundation of China[11805233] ; National Natural Science Foundation of China[11975266] ; National Natural Science Foundation of China[U19A20113]
WOS研究方向	Nuclear Science & Technology
语种	英语
出版者	ELSEVIER
WOS记录号	WOS:000628782500064
资助机构	US Department of Energy ; National Key Research and Development Program of China ; National Natural Science Foundation of China
内容类型	期刊论文
源URL	[http://ir.hfcas.ac.cn:8080/handle/334002/121373]
专题	中国科学院合肥物质科学研究院
通讯作者	Baek, S. G.; Li, M. H.; Ding, B. J.
作者单位	1.MIT, Plasma Sci & Fus Ctr, 77 Massachusetts Ave, Cambridge, MA 02139 USA 2.Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA 3.Chinese Acad Sci, Inst Plasma Phys, Hefei 230031, Peoples R China
推荐引用方式 GB/T 7714	Baek, S. G.,Li, M. H.,Wallace, G. M.,et al. Impact of lithium wall conditioning and wave-frequency on high density lower hybrid current drive experiment on EAST[J]. NUCLEAR MATERIALS AND ENERGY,2021,26.
APA	Baek, S. G..,Li, M. H..,Wallace, G. M..,Bonoli, P. T..,Choi, W..,...&Zhao, H..(2021).Impact of lithium wall conditioning and wave-frequency on high density lower hybrid current drive experiment on EAST.NUCLEAR MATERIALS AND ENERGY,26.
MLA	Baek, S. G.,et al."Impact of lithium wall conditioning and wave-frequency on high density lower hybrid current drive experiment on EAST".NUCLEAR MATERIALS AND ENERGY 26(2021).