Abstract Multi-channel soft x-ray (SX) detectors are applied to generate images of magnetohydrodynamic (MHD) oscillation on the HT-7 tokamak, and the data from SX cameras are analysed by using the Fourier--Bessel harmonic reconstruction method and the singular value decomposition. The image reconstruction of SX emissivity is obtained on the assumption of plasma rigid rotation. One of the important phenomena in the HT-7 discharge is the transition from the sawtooth oscillations to the MHD oscillations when the plasma density grows higher. The MHD structure observed in the SX tomography is featured as follows: the magnetic surface of MHD structure is made up of the crescent-shaped ``hot core'' and the circular ``cold bubble''. The structure of the magnetic surface is relatively stable. It rotates in the direction of the electron diamagnetic drift at a frequency being the oscillation frequency of the MHD oscillations.
Received: 01 July 2005
Revised: 26 August 2005
Accepted manuscript online:
Fund: Project Supported by the National Natural Science Foundation of China (Grant Nos 10375070 and 10305012).
Cite this article:
Ma Tian-Peng (马天鹏), Ruan Huai-Lin (阮怀林), Hu Li-Qun (胡立群), Wan Bao-Nian (万宝年), Gao Xiang (高翔), Zhen Xiang-Jun (甄香君), Zhou Li-Wu (周立武), Sun You-Wen (孙有文), Gao Wei (高伟), Chen Zhong-Yong (陈忠勇), Lin Shi-Yao (林士耀), Kong Wei (孔伟) Tomographic analysis of the central magnetohydrodynamic oscillations on the HT-7 tokamak 2006 Chinese Physics 15 593
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