Item type |
学術雑誌論文 / Journal Article(1) |
公開日 |
2023-03-03 |
タイトル |
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タイトル |
Ion temperature clamping in Wendelstein 7-X electron cyclotron heated plasmas |
言語 |
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言語 |
eng |
キーワード |
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主題Scheme |
Other |
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主題 |
turbulent transport |
キーワード |
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主題Scheme |
Other |
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主題 |
electron heated plasmas |
キーワード |
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主題Scheme |
Other |
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主題 |
ion heat transport |
キーワード |
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主題Scheme |
Other |
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主題 |
neoclassically optimised stellarator |
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主題Scheme |
Other |
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主題 |
power balance |
キーワード |
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主題Scheme |
Other |
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主題 |
profile stiffness |
キーワード |
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主題Scheme |
Other |
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主題 |
ion temperature clampingElectron cyclotron heating |
資源タイプ |
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資源タイプ識別子 |
http://purl.org/coar/resource_type/c_6501 |
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資源タイプ |
journal article |
著者 |
BEURSKENS, Marc
BOZHENKOV, Sergey
FORD, O.
XANTHOPUOLOS, Pavlos
ZOCCO, Alessandro
TURKIN, Yuri
ALONSO, Juan Arturo
BEIDLER, Craig
CALVO, I.
CARRALERO, Daniel
ESTRADA, Teresa
FUCHERT, Golo
GRULKE, O.
HIRSCH, M.
IDA, Katsumi
JAKUBOWSKI, Marcin
KILLER, Carsten
KRYCHOWIAK, Maciej
KWAK, Sehyun
LAZERSON, Samuel
LANGENBERG, Andreas
LUNSFORD, Robert
PABLANT, Novimir
PASCH, E.
PAVONE, Andrea
REIMOLD, F.
ROMBA, Thilo
STECHOW, A. von
SMITH, H. M.
WINDISCH, T.
YOSHINUMA, Mikirou
ZHANG, Daihong
WOLF, Robert
the W7-X Team
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著者ID |
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内容記述タイプ |
Other |
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内容記述 |
0000-0002-3354-0279 |
抄録 |
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内容記述タイプ |
Abstract |
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内容記述 |
The neoclassical transport optimization of the Wendelstein 7-X stellarator has not resulted in the predicted high energy confinement of gas fueled electron-cyclotron-resonance-heated (ECRH) plasmas as modelled in (Turkin et al 2011 Phys. Plasmas 18 022505) due to high levels of turbulent heat transport observed in the experiments. The electron-turbulent-heat transport appears non-stiff and is of the electron temperature gradient (ETG)/ion temperature gradient (ITG) type (Weir et al 2021 Nucl. Fusion 61 056001). As a result, the electron temperature Te can be varied freely from 1 keV–10 keV within the range of PECRH = 1–7 MW, with electron density ne values from 0.1–1.5 × 1020 m−3. By contrast, in combination with the broad electron-to-ion energy-exchange heating profile in ECRH plasmas, ion-turbulent-heat transport leads to clamping of the central ion temperature at Ti ∼ 1.5 keV ± 0.2 keV. In a dedicated ECRH power scan at a constant density of 〈ne〉 = 7 × 1019 m−3, an apparent 'negative ion temperature profile stiffness' was found in the central plasma for (r/a < 0.5), in which the normalized gradient ∇Ti/Ti decreases with increasing ion heat flux. The experiment was conducted in helium, which has a higher radiative density limit compared to hydrogen, allowing a broader power scan. This 'negative stiffness' is due to a strong exacerbation of turbulent transport with an increasing ratio of Te/Ti in this electron-heated plasma. This finding is consistent with electrostatic microinstabilities, such as ITG-driven turbulence. Theoretical calculations made by both linear and nonlinear gyro-kinetic simulations performed by the GENE code in the W7-X three-dimensional geometry show a strong enhancement of turbulence with an increasing ratio of Te/Ti. The exacerbation of turbulence with increasing Te/Ti is also found in tokamaks and inherently enhances ion heat transport in electron-heated plasmas. This finding strongly affects the prospects of future high-performance gas-fueled ECRH scenarios in W7-X and imposes a requirement for turbulence-suppression techniques. |
書誌情報 |
Nuclear Fusion
巻 61,
号 11,
p. 116072,
発行日 2021-10-25
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出版者 |
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出版者 |
IOP Publishing |
ISSN |
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収録物識別子タイプ |
ISSN |
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収録物識別子 |
0029-5515 |
書誌レコードID |
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収録物識別子タイプ |
NCID |
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収録物識別子 |
AA00759871 |
DOI |
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関連タイプ |
isIdenticalTo |
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識別子タイプ |
DOI |
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関連識別子 |
10.1088/1741-4326/ac1653 |
権利 |
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権利情報 |
© EURATOM 2021 |
権利 |
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権利情報 |
Original content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. |
権利 |
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権利情報 |
Any further distribution of this work mustmaintain attribution to the author(s) and the title of the work, journal citation and DOI. |
情報源 |
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関連名称 |
M.N.A. Beurskens et al 2021 Nucl. Fusion 61 116072 |
関連サイト |
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識別子タイプ |
DOI |
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関連識別子 |
http://doi.org/10.1088/1741-4326/ac1653 |
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関連名称 |
Publisher version |
著者版フラグ |
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出版タイプ |
VoR |
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出版タイプResource |
http://purl.org/coar/version/c_970fb48d4fbd8a85 |