Magnetohydrodynamics-induced internal crash near density limit in ohmic discharge on experimental advanced superconducting tokamak

doi:10.1088/1402-4896/ab62d6

	Magnetohydrodynamics-induced internal crash near density limit in ohmic discharge on experimental advanced superconducting tokamak
	Xu, L. Q.1; Duan, Y. M.1; Shen, W.1; Yuan, Y.1,2; Chao, Y.1,2; Mao, S. T.1; Lin, S. Y.1; Chen, K. Y.1; Hu, L. Q.1
刊名	PHYSICA SCRIPTA
	2020-05-01
卷号	95
关键词	soft x-ray tomography tokamak diagnostics MHD 3D MHD nonlinear simulation
ISSN号	0031-8949
DOI	10.1088/1402-4896/ab62d6
通讯作者	Duan, Y. M.(ymduan@ipp.cas.cn) ; Lin, S. Y.(linsy@ipp.ac.cn)
英文摘要	The magnetohydrodynamics (MHD)-induced internal crash (IC) is one of the most fundamental dynamics of a tokamak discharge. Study of IC and the consequent formation of seed island (for neo-classical tearing modes) are still attractive in both experimental and numerical studies. In this work, a set of MHD-induced sawtooth like crashes (SLCs) have been observed in experimental advanced superconducting tokamak (EAST) ohmic discharge near density limit. With the tomography of high-resolution upgraded soft x-ray imaging system, it is observed that m/n = 2/1 tearing mode converts to a m/n = 1/1 instability, and it then triggers crash in the plasma core, here, m is the poloidal mode number and n is the toroidal mode number. Similar to sawtooth crash (SC), the crash of SLC here is due to m/n = 1/1 mode nonlinear dynamic. An extended MHD simulation code M3D is used to understand of the dynamics of m/n = 1/1 internal kink mode in SC in torus. A complex SC is reproduced from M3D nonlinear simulation under EAST realistic magnetic flux equilibrium and experimental resistivity. The rapid growth of unstable m/n = 1/1 kink and interaction with its higher harmonics, are responsible for SC. The simulation results show an existence of annular chaos belt outside q = 1 surface during SC. Furthermore, magnetic islands with higher poloidal mode number are found after SC. The formation of island after SC make plasma current profile flat in the core.
资助项目	National Natural Science Foundation of China[11575247] ; National Natural Science Foundation of China[11975273] ; National Natural Science Foundation of China[11605243]
WOS关键词	CYCLOTRON EMISSION MEASUREMENTS ; SAWTOOTH OSCILLATIONS ; INSTABILITIES ; DISRUPTIONS ; SAWTEETH
WOS研究方向	Physics
语种	英语
出版者	IOP PUBLISHING LTD
WOS记录号	WOS:000537676900002
资助机构	National Natural Science Foundation of China
内容类型	期刊论文
源URL	[http://ir.hfcas.ac.cn:8080/handle/334002/103079]
专题	中国科学院合肥物质科学研究院
通讯作者	Duan, Y. M.; Lin, S. Y.
作者单位	1.CAS Hefei, Inst Plasma Phys, Hefei 230031, Anhui, Peoples R China 2.Univ Sci & Technol China, Hefei 230026, Anhui, Peoples R China
推荐引用方式 GB/T 7714	Xu, L. Q.,Duan, Y. M.,Shen, W.,et al. Magnetohydrodynamics-induced internal crash near density limit in ohmic discharge on experimental advanced superconducting tokamak[J]. PHYSICA SCRIPTA,2020,95.
APA	Xu, L. Q..,Duan, Y. M..,Shen, W..,Yuan, Y..,Chao, Y..,...&Hu, L. Q..(2020).Magnetohydrodynamics-induced internal crash near density limit in ohmic discharge on experimental advanced superconducting tokamak.PHYSICA SCRIPTA,95.
MLA	Xu, L. Q.,et al."Magnetohydrodynamics-induced internal crash near density limit in ohmic discharge on experimental advanced superconducting tokamak".PHYSICA SCRIPTA 95(2020).