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22-27 October 2018
Mahatma Mandir Conference Centre
Asia/Kolkata timezone
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Localized modulation of turbulence by magnetic islands on HL-2A tokamak

25 Oct 2018, 08:30
4h
Mahatma Mandir Conference Centre

Mahatma Mandir Conference Centre

Gandhinagar (nearest Airport: Ahmedabad), India
Poster P5 Posters

Speaker

Min Jiang (Southwestern Institute of Physics)

Description

Magnetic islands formed in magnetically confined plasmas have significant influence on plasma profiles and cross-field transport, and can even cause plasma disruption [1,2]. However, observations of internal transport barriers near the rational magnetic surface suggest the importance of magnetic islands in plasma confinement via increase of flow shear at the island boundary [3,4]. In recent years the multi-scale interaction between large-scale modes and micro-scale turbulence has been found to play an important role in regulating turbulent transport and eventually form the low to high mode transition [5,6]. In this paper, modulation on turbulent electron temperature fluctuations and density fluctuations by an m/n =1/1 tearing mode island was observed in the core plasma region of the HL-2A tokamak. High tempo-spatial resolution two-dimensional images of temperature fluctuations show the first evidence that the turbulence modulation occurs only when the island width exceeds a certain threshold value (6.4 cm) and the modulation is localized merely in the inner half area of the island due to significant alteration of local profiles and turbulence drives. Evidence also reveals that for large islands turbulence spreading takes place across the flat temperature of the O-point at the inner half island region, whereas in the outer half area the small temperature gradient drives a low level of temperature fluctuations. [1] G. Fiksel et al 1995 Phys. Rev. Lett. 75 3866. [2] W. Suttrop et al 1997 Nucl. Fusion 37 119. [3] K. Ida et al 2002 Phys. Rev. Lett. 88 015002. [4] E. Joffrin et al 2003 Nucl. Fusion 43 1167. [5] A. Fujisawa et al 2004 Phys. Rev. Lett. 93 165002. [6] I. Shesterikov et al 2013 Phys. Rev. Lett. 111 055006.
Country or International Organization China, People's Republic of
Paper Number EX/P5-4

Primary author

Min Jiang (Southwestern Institute of Physics)

Co-authors

B.S. Yuan (Southwestern Institute of Physics) Dr Deliang Yu (Southwestern Institute of Physics) Prof. Jiquan Li (Kyoto University) Mr Min Xu (Southwestern Institute of Physics) P.W. Shi (Southwestern Institute of Physics) Q.W. Yang (Southwestern Institute of Physics) Dr Wei Chen (Southwestern Institute of Physics, P.O. Box 432 Chengdu 610041, China) Dr Wulyu Zhong (CnSWIP) Dr Xiaoquan JI (Southwestern Institute of Physics, Chengdu 610041 China) Prof. Xuantong Ding (Southwestern Institute of Physics) Y. Zhou (Southwestern Institute of Physics) Y.G. Li (Southwestern Institute of Physics) Prof. Yi Liu (southwestern institute of physics) Prof. Yuhong Xu (Southwest Jiaotong University) Z.C. Yang (Southwestern Institute of Physics) Dr Zhongbing Shi (Southwestern Institute of Physics)

Presentation Materials

Paper