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Microtearing modes ...
Microtearing modes as the source of magnetic fluctuations in the JET pedestal
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- Hatch, D. R. (author)
- Univ Texas Austin, Inst Fus Studies, Austin, TX 78712 USA.
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- Kotschenreuther, M. (author)
- Univ Texas Austin, Inst Fus Studies, Austin, TX 78712 USA.
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- Mahajan, S. M. (author)
- Univ Texas Austin, Inst Fus Studies, Austin, TX 78712 USA.
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- Pueschel, M. J. (author)
- Univ Texas Austin, Inst Fus Studies, Austin, TX 78712 USA.
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- Michoski, C. (author)
- Univ Texas Austin, Oden Inst Computat Engn & Sci, Austin, TX 78712 USA.
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- Merlo, G. (author)
- Univ Texas Austin, Oden Inst Computat Engn & Sci, Austin, TX 78712 USA.
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- Hassan, E. (author)
- Univ Texas Austin, Inst Fus Studies, Austin, TX 78712 USA.
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- Field, A. R. (author)
- Culham Sci Ctr, CCFE, Abingdon OX14 3DB, Oxon, England.
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- Frassinetti, Lorenzo (author)
- KTH,Fusionsplasmafysik
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- Giroud, C. (author)
- Culham Sci Ctr, CCFE, Abingdon OX14 3DB, Oxon, England.
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- Hillesheim, J. C. (author)
- Culham Sci Ctr, CCFE, Abingdon OX14 3DB, Oxon, England.
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- Maggi, C. F. (author)
- Culham Sci Ctr, CCFE, Abingdon OX14 3DB, Oxon, England.
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- von Thun, C. Perez (author)
- Inst Plasma Phys & Laser Microfus, Hery 23, PL-01497 Warsaw, Poland.
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- Roach, C. M. (author)
- Culham Sci Ctr, CCFE, Abingdon OX14 3DB, Oxon, England.
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- Saarelma, S. (author)
- Culham Sci Ctr, CCFE, Abingdon OX14 3DB, Oxon, England.
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- Jarema, D. (author)
- Max Planck Inst Plasma Phys, Boltzmannstr 2, D-85748 Garching, Germany.
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- Jenko, F. (author)
- Univ Texas Austin, Inst Fus Studies, Austin, TX 78712 USA.;Univ Texas Austin, Oden Inst Computat Engn & Sci, Austin, TX 78712 USA.;Max Planck Inst Plasma Phys, Boltzmannstr 2, D-85748 Garching, Germany.
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Univ Texas Austin, Inst Fus Studies, Austin, TX 78712 USA Univ Texas Austin, Oden Inst Computat Engn & Sci, Austin, TX 78712 USA. (creator_code:org_t)
- 2021-02-08
- 2021
- English.
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In: Nuclear Fusion. - : IOP Publishing. - 0029-5515 .- 1741-4326. ; 61:3
- Related links:
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http://arxiv.org/pdf...
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https://urn.kb.se/re...
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https://doi.org/10.1...
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Abstract
Subject headings
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- We report on a detailed study of magnetic fluctuations in the JET pedestal, employing basic theoretical considerations, gyrokinetic simulations, and experimental fluctuation data to establish the physical basis for their origin, role, and distinctive characteristics. We demonstrate quantitative agreement between gyrokinetic simulations of microtearing modes (MTMs) and two magnetic frequency bands with corresponding toroidal mode numbers n = 4 and 8. Such disparate fluctuation scales, with substantial gaps between toroidal mode numbers, are commonly observed in pedestal fluctuations. Here we provide a clear explanation, namely the alignment of the relevant rational surfaces (and not others) with the peak in the omega(*) profile, which is localized in the steep gradient region of the pedestal. We demonstrate that a global treatment is required to capture this effect. Nonlinear simulations suggest that the MTM fluctuations produce experimentally-relevant transport levels and saturate by relaxing the background electron temperature gradient, slightly downshifting the fluctuation frequencies from the linear predictions. Scans in collisionality are compared with a simple MTM dispersion relation. At the experimental points considered, MTM growth rates can either increase or decrease with collision frequency depending on the parameters thus defying any simple characterization of collisionality dependence.
Subject headings
- NATURVETENSKAP -- Fysik (hsv//swe)
- NATURAL SCIENCES -- Physical Sciences (hsv//eng)
Keyword
- pedestal
- microtearing
- gyrokinetics
- transport
Publication and Content Type
- ref (subject category)
- art (subject category)
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To the university's database
- By the author/editor
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Hatch, D. R.
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Kotschenreuther, ...
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Mahajan, S. M.
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Pueschel, M. J.
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Michoski, C.
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Merlo, G.
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Hassan, E.
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Field, A. R.
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Frassinetti, Lor ...
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Giroud, C.
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Hillesheim, J. C ...
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Maggi, C. F.
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von Thun, C. Per ...
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Roach, C. M.
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Saarelma, S.
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Jarema, D.
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Jenko, F.
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- About the subject
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- NATURAL SCIENCES
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NATURAL SCIENCES
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and Physical Science ...
- Articles in the publication
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Nuclear Fusion
- By the university
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Royal Institute of Technology