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Title: Effect of pressure-driven MHD instabilities on confinement in reactor-relevant high-beta helical plasmas

Abstract

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.

Authors:
; ; ; ; ; ; ;  [1];  [2];  [3]
  1. National Institute for Fusion Science, Toki 509-5292 (Japan)
  2. Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585 (Japan)
  3. Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan)
Publication Date:
OSTI Identifier:
21537882
Resource Type:
Journal Article
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 18; Journal Issue: 5; Other Information: DOI: 10.1063/1.3592675; (c) 2011 American Institute of Physics; Journal ID: ISSN 1070-664X
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; CONFINEMENT TIME; HIGH-BETA PLASMA; LHD DEVICE; MAGNETOHYDRODYNAMICS; PLASMA CONFINEMENT; PLASMA INSTABILITY; TURBULENCE; CLOSED PLASMA DEVICES; CONFINEMENT; FLUID MECHANICS; HYDRODYNAMICS; INSTABILITY; MECHANICS; PLASMA; THERMONUCLEAR DEVICES

Citation Formats

Watanabe, K Y, Takemura, Y, Funaba, H, Sakakibara, S, Tanaka, K, Ohdachi, S, Toi, K, Narushima, Y, Masamune, S, and Watanabe, F. Effect of pressure-driven MHD instabilities on confinement in reactor-relevant high-beta helical plasmas. United States: N. p., 2011. Web. doi:10.1063/1.3592675.
Watanabe, K Y, Takemura, Y, Funaba, H, Sakakibara, S, Tanaka, K, Ohdachi, S, Toi, K, Narushima, Y, Masamune, S, & Watanabe, F. Effect of pressure-driven MHD instabilities on confinement in reactor-relevant high-beta helical plasmas. United States. https://doi.org/10.1063/1.3592675
Watanabe, K Y, Takemura, Y, Funaba, H, Sakakibara, S, Tanaka, K, Ohdachi, S, Toi, K, Narushima, Y, Masamune, S, and Watanabe, F. 2011. "Effect of pressure-driven MHD instabilities on confinement in reactor-relevant high-beta helical plasmas". United States. https://doi.org/10.1063/1.3592675.
@article{osti_21537882,
title = {Effect of pressure-driven MHD instabilities on confinement in reactor-relevant high-beta helical plasmas},
author = {Watanabe, K Y and Takemura, Y and Funaba, H and Sakakibara, S and Tanaka, K and Ohdachi, S and Toi, K and Narushima, Y and Masamune, S and Watanabe, F},
abstractNote = {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.},
doi = {10.1063/1.3592675},
url = {https://www.osti.gov/biblio/21537882}, journal = {Physics of Plasmas},
issn = {1070-664X},
number = 5,
volume = 18,
place = {United States},
year = {Sun May 15 00:00:00 EDT 2011},
month = {Sun May 15 00:00:00 EDT 2011}
}