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arXiv · 1705.09487

Multiscale interaction between a large scale magnetic island and small scale turbulence

M. J. Choi·J. Kim·J. -M. Kwon·H. K. Park·Y. In·W. Lee·K. D. Lee·G. S. Yun·J. Lee·M. Kim·W. -H. Ko·J. H. Lee·Y. S. Park·Y. -S. Na·N. C. Luhmann Jr·B. H. Park
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Abstract

Multiscale interaction between the magnetic island and turbulence has been demonstrated through simultaneous two-dimensional measurements of turbulence and temperature and flow profiles. The magnetic island and turbulence mutually interact via the coupling between the electron temperature ($T_e$) gradient, the $T_e$ turbulence, and the poloidal flow. The $T_e$ gradient altered by the magnetic island is peaked outside and flattened inside the island. The $T_e$ turbulence can appear in the increased $T_e$ gradient regions. The combined effects of the $T_e$ gradient and the the poloidal flow shear determine two-dimensional distribution of the $T_e$ turbulence. When the reversed poloidal flow forms, it can maintain the steepest $T_e$ gradient and the magnetic island acts more like a electron heat transport barrier. Interestingly, when the $T_e$ gradient, the $T_e$ turbulence, and the flow shear increase beyond critical levels, the magnetic island turns into a fast electron heat transport channel, which directly leads to the minor disruption.

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M. J. Choi, J. Kim, J. -M. Kwon, H. K. Park, Y. In, W. Lee, K. D. Lee, G. S. Yun, J. Lee, M. Kim, W. -H. Ko, J. H. Lee, Y. S. Park, Y. -S. Na, N. C. Luhmann Jr, B. H. Park. 2017-05-26. Multiscale interaction between a large scale magnetic island and small scale turbulence. https://doi.org/10.1088/1741-4326/aa86fe

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