Penetration of n = 2 resonant magnetic field perturbations in EAST

doi:10.1088/1741-4326/abea57

	Penetration of n = 2 resonant magnetic field perturbations in EAST
	Ren, Jie 1,4; Sun, You-Wen 1; Wang, Hui-Hui 1; Gu, Shuai 2,3; Qian, Jin-Ping 1; Shi, Tong-Hui 1; Shen, Biao 1; Liu, Yue-Qiang 2; Guo, Wen-Feng 1; Chu, Nan 1
刊名	NUCLEAR FUSION
	2021-05-01
卷号	61
关键词	tokamak field penetration intrinsic error field phasing scan mode coupling
ISSN号	0029-5515
DOI	10.1088/1741-4326/abea57
通讯作者	Sun, You-Wen(ywsun@ipp.ac.cn)
英文摘要	This paper presents the penetration of n = 2 magnetic field perturbations, where n is the toroidal mode number. The n = 2 intrinsic error field (IEF) is measured in an ohmic heating plasma using the compass scan method, i.e. the toroidal asymmetry in the threshold current for the penetration of n = 2 resonant magnetic perturbations (RMPs). Its amplitude is 55.5 A in equivalent coil current or B-r,B-3/2 = 0.1 G and the toroidal phase of the IEF is around 170.6 degrees (129 degrees). Phasing scans (scans of the phase difference between the upper and lower coil currents) of the n = 2 RMPs are carried out to obtain the effects of the n = 2 spectrum on field penetration. The observed dependence of the field penetration on the spectrum is consistent with those of simulations using the MARS-F code. One of the interesting phenomena is that the n = 2 mode often stimulates an n = 1 mode. The dominant poloidal harmonic of the n = 1 mode is m = 2, and the dominant poloidal harmonic of the n = 2 mode is m = 3. The evolution of the n = 1 mode has two stages, i.e., an initial small island growth stage, and a later saturation stage. In the initial stage, the amplitude of the n = 1 magnetic island grows, while the phase remains fixed. When the amplitude of the magnetic island exceeds a certain threshold, it enters the second stage, in which the magnetic island is locked into another phase and its amplitude starts to saturate. The phase in the initial small island stage depends linearly on the phase of the applied n = 2 RMP, which suggests that the n = 2 mode is directly driven by the coupling between the n = 1 and n = 2 modes. The phase in the second stage is either locked to the phase close to the previously measured n = 1 IEF, or is locked to the phase close to the n = 2 response field. This suggests that the final phase of the n = 1 mode depends on competition between the locking effect induced by the n = 1 IEF and the nonlinear coupling effect between the two modes. This might be an issue in the MHD control application using high-n RMPs in the future ITER device.
资助项目	National Key R&D Program of China[2017YFE0301100] ; National Natural Science Foundation of China[11875292] ; National Natural Science Foundation of China[11805237]
WOS研究方向	Physics
语种	英语
出版者	IOP PUBLISHING LTD
WOS记录号	WOS:000639931100001
资助机构	National Key R&D 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/334002/121982]
专题	中国科学院合肥物质科学研究院
通讯作者	Sun, You-Wen
作者单位	1.Chinese Acad Sci, Inst Plasma Phys, Hefei 230031, Peoples R China 2.Oak Ridge Associated Univ, Oak Ridge, TN 37830 USA 3.Gen Atom, POB 85608, San Diego, CA 92186 USA 4.Univ Sci & Technol China, Hefei 230026, Peoples R China
推荐引用方式 GB/T 7714	Ren, Jie,Sun, You-Wen,Wang, Hui-Hui,et al. Penetration of n = 2 resonant magnetic field perturbations in EAST[J]. NUCLEAR FUSION,2021,61.
APA	Ren, Jie.,Sun, You-Wen.,Wang, Hui-Hui.,Gu, Shuai.,Qian, Jin-Ping.,...&Wan, Bao-Nian.(2021).Penetration of n = 2 resonant magnetic field perturbations in EAST.NUCLEAR FUSION,61.
MLA	Ren, Jie,et al."Penetration of n = 2 resonant magnetic field perturbations in EAST".NUCLEAR FUSION 61(2021).