1. Control system of neoclassical tearing modes in real time on HL-2A tokamak.
- Author
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Longwen Yan, Xiaoquan Ji, Shaodong Song, Fan Xia, Yuan Xu, Jiruo Ye, Min Jiang, Wenjin Chen, Tengfei Sun, Shaoyong Liang, Fei Ling, Rui Ma, Mei Huang, Hongpeng Qu, Xianming Song, Deliang Yu, Zhongbin Shi, Yi Liu, Qingwei Yang, and Min Xu
- Subjects
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TOKAMAKS , *MAGNETOHYDRODYNAMICS , *PLASMA stability , *FUSION reactors , *PINCH effect (Physics) - Abstract
The stability and performance of tokamak plasmas are routinely limited by various magnetohydrodynamic instabilities, such as neoclassical tearing modes (NTMs). This paper presents a rather simple method to control the NTMs in real time (RT) on a tokamak, including the control principle of a feedback approach for RT suppression and stabilization for the NTMs. The control system combines Mirnov, electron cyclotron emission, and soft X-ray diagnostics used for determining the NTM positions. A methodology for fast detection of 2/1 or 3/2 NTM positions with 129 x 129 grid reconstruction is elucidated. The forty poloidal angles for steering the electron cyclotron resonance heating (ECRH)/electron cyclotron current drive launcher are used to establish the alignment of antenna mirrors with the center of the NTM and to ensure launcher emission intersecting with the rational surface of a magnetic island. Pilot experiments demonstrate the RT control capability to trace the conventional tearing modes (CTMs) in the HL-2A tokamak. The 2/1 CTMs have been suppressed or stabilized by the ECRH power deposition on site or with the steerable launcher. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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