Experimental study on intrinsic impurity induced snake for EAST tokamak

doi:10.16568/j.0254-6086.201602004

Abstract

Abstract:

The dynamics and spatial structure of intrinsic impurity induced core 3D snake instability were experimentally studied by means of multi-arrays high temporal and spatial resolution soft X-ray imaging system in EAST. Two types of spontaneous snake were identified regarding to the relationship between sawtooth and snake. The frequency spectra of first type snake is shaped as letters ‘V’ or ‘W’, and the structure of hot core appear in circular. Another type of snake coexists with sawtooth crash. The frequency spectra of this type snake are shaped like a palm, and it grow to a large crescent-shaped helical island-like structure. The second type snake with a bigger radial displacement than the first one and it can trigger 2/1 new-classical tearing mode via mode coupling.

Key words: Snake, Soft X-ray imaging, EAST tokamak, Sawtooth crash

摘要：

利用多阵列高时空分辨的软X 射线阵列成像系统对EAST 芯部固有杂质驱动的蛇形振荡进行时间动态演化和空间结构反演研究，研究了实验上发现的两种时空行为明显不同的两类蛇形振荡，一类具有字母V 或W形状的动态频谱，空间上为理想近圆状热芯结构；另外一类蛇形振荡和锯齿崩塌共存，振荡的频谱呈现手掌状，空间上为很大的电阻性月牙形磁岛结构。结果表明，锯齿共存的蛇形振荡的饱和径向扰动位移通常比无锯齿的蛇形振荡大，并且会触发边界的新经典撕裂模。

关键词: 蛇形振荡, 软X 射线诊断, EAST 装置, 锯齿振荡

CLC Number:

TL65+1

MA Tian-peng1, XU Li-qing2, HU Li-qun2. Experimental study on intrinsic impurity induced snake for EAST tokamak[J]. NUCLEAR FUSION AND PLASMA PHYSICS, 2016, 36(2): 119-125.

马天鹏1，徐立清*2，胡立群2. EAST 装置固有杂质驱动蛇形振荡行为研究[J]. 核聚变与等离子体物理, 2016, 36(2): 119-125.

References

[1] Weller A, Cheetham A D, Edwards A W, et al. Persistent density perturbations at rational-q surfaces following pellet injection in the Joint European Torus [J]. Phys. Rev.Lett., 1987, 59: 2303.
[2] Gill R D, Edwards A W, Pasini D, et al. Snake-like density perturbations in JET [J]. Nucl. Fusion, 1992, 32: 723.
[3] Wesson J A. Snakes [J]. Plasma Phys. Contr. Fusion,1995, 37: A337−A346.
[4] Pecquet A L, Cristofani P, Mattioli M, et al. Snake-like phenomena in Tore Supra following pellet injection [J].Nucl. Fusion, 1997, 37: 451.
[5] Liu Y, Qiu X M, Dong Y B, et al. Snake perturbations during pellet injection and LHCD in the HL-1M tokamak[J]. Plasma Phys. Contr. Fusion, 2004, 46: 455.
[6] Liu Y, Qiu X M, Dong Y B, et al. Sawtooth-stabilization and snake-excitation during LHCD on the HL-1M[J].Chin. Phys. Lett., 2004, 21: 360.
[7] Delgado-Aparicio L, Sugiyama L, Granetz R, et al.Formation and stability of impurity ‘‘snakes’’ in tokamak plasmas[J]. Phys. Rev. Lett., 2013, 110: 065006.
[8] Delgado-Aparicio L, Sugiyama L, Granetz R, et al. On the formation and stability of long-lived impurity-ion snakes in Alcator C-Mod[J]. Nucl. Fusion, 2013. 53:043019.
[9] Xu L Q, Hu L Q, Chen K Y, et al. Observation of 1/1 impurity-related ideal internal kink mode locking in the EAST tokamak[J]. Plasma Phys. Contr. Fusion, 2013, 55:032001.
[10] Xu L Q, Hu L Q, Chen K Y, et al. Repetitive ‘snakes’ and their damping effect on core toroidal rotation in EAST plasmas with multiple H-L-H transitions[J]. Chin. Phys.Lett., 2014, 31: 105201.
[11] Xu L Q, Hu L Q, Chen K Y, et al. Observations of pressure gradient driven m=1 internal kink mode in EAST tokamak[J]. Phys. Plasmas, 2012, 19: 122504.
[12] Shi T H, Wan B N, Shen B, et al. Excitation of (2,1) neoclassical tearing modes by mode coupling with (1,1)internal mode in EAST[J]. Plasma Phys. Contr. Fusion,2013, 55: 055007.
[13] 马天鹏, 胡立群, 陈开云. 小波变换在HT-7 托卡马克磁流体力学振荡动态频谱分析中的应用[J]. 物理学报, 2010, 59: 7209.

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