Effect of pressure-driven MHD instabilities on confinement in reactor-relevant high-beta helical plasmas
- National Institute for Fusion Science, Toki 509-5292 (Japan)
- Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585 (Japan)
- Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan)
Through the experiment data analysis in the large helical device (LHD), the influence of the global MHD instability and the relatively short wave length MHD instabilities driven turbulence on the confinement performance in reactor-relevant high-beta helical plasmas is studied. The comparison of the energy confinement time between just before global MHD instability disappears and after that, and the estimation of the saturated mode structure by the multi-channel soft x-ray measurement enable us to quantitatively estimate the influence of the global interchange type MHD instability with different saturated mode structures on the confinement performance. According to the comparison between thermal conductivities in experiments and those predicted by theoretical transport models, the transport properties in the peripheral region of high beta LHD plasmas are quite similar with anomalous transport model based on an interchange type MHD instability driven turbulence, and that result is supported by the dependence of the density fluctuation with relatively short wave length on beta value.
- OSTI ID:
- 21537882
- Journal Information:
- Physics of Plasmas, Vol. 18, Issue 5; Other Information: DOI: 10.1063/1.3592675; (c) 2011 American Institute of Physics; ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
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