Tungsten control in type-I ELMy H-mode plasmas on EAST

Zong Xu; Zhen-Wei Wu; Ling Zhang; Yun-Xing Cheng; Wei Gao; Xiao-Dong Lin; Xiang Gao; Ying-Jie Chen; Yue-Heng Huang; Juan Huang; Qing Zang; Yin-Xian Jie; Yan-Min Duan; Ying-Ying Li; Hai-Qing Liu; Guo-Sheng Xu; EAST team

doi:10.1007/s41365-021-00929-4

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Tungsten control in type-I ELMy H-mode plasmas on EAST

ACCELERATOR, RAY TECHNOLOGY AND APPLICATIONS | Updated：2021-09-30

- Tungsten control in type-I ELMy H-mode plasmas on EAST
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- Nuclear Science and Techniques Vol. 32, Issue 9, Article number: 95(2021)
- Affiliations：
  
  1.Advanced Energy Research Center, Shenzhen University, Shenzhen 518060, China
  2.Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060,China
  3.Institute of Plasma Physics, Chinese Academy of Science, Hefei 230031, China
  4.University of Science & Technology of China, Hefei 230031, China
- Author bio：
  
  E-mail:Zhen-Wei Wu zwwu@ipp.ac.cn,
  Ling Zhang zhangling@ipp.ac.cn
- Funds：
- DOI：10.1007/s41365-021-00929-4
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Zong Xu, Zhen-Wei Wu, Ling Zhang, et al. Tungsten control in type-I ELMy H-mode plasmas on EAST. [J]. Nuclear Science and Techniques 32(9):95(2021)
DOI：

Zong Xu, Zhen-Wei Wu, Ling Zhang, et al. Tungsten control in type-I ELMy H-mode plasmas on EAST. [J]. Nuclear Science and Techniques 32(9):95(2021) DOI： 10.1007/s41365-021-00929-4.

摘要

Abstract

The first experimental investigation of the tungsten behavior in ELMy H-mode plasmas with co-/counter neutral beam injection (NBI) and unfavorable/favorable ,B,t, was performed on EAST. Tungsten was found to accumulate easily in ELMy H-mode plasma with co-NBI heating and unfavorable ,B,t,. Thus, in this case the tungsten concentration can exceed 10,−4, resulting in degradation of the plasma confinement and periodic H-L transitions. To reduce the tungsten concentration in steady-state type-I ELMy H-mode operation, counter-NBI is applied to modify the density and temperature and brake the plasma toroidal rotation. The applied counter-NBI decreases the PHZ+,E,r, inward pinch velocity and reverses the direction of neoclassical inward convection, thus decreasing the tungsten concentration from ~7 × 10,−5, to ~2 × 10,−5, in type-I ELMy H-mode plasma with favorable ,B,t,. A comparison of the effects of different ,B,t, directions on the tungsten behavior also shows that favorable ,B,t, is beneficial for reducing the tungsten concentration in the core plasma. These results imply that counter-NBI with favorable ,B,t, can effectively prevent tungsten accumulation and expand the operating window for exploring steady-state type-I ELMy H-mode operation of EAST.

关键词

Keywords

Tungsten accumulationCounter-NBIfavorable BtELMy H-modeEAST

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