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Diamond PH, Singh R, Long T, Hong R, Ke R, Yan Z, Cao M, Tynan GR. How the birth and death of shear layers determine confinement evolution: from the L → H transition to the density limit. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2023; 381:20210227. [PMID: 36587820 DOI: 10.1098/rsta.2021.0227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Accepted: 11/05/2022] [Indexed: 06/17/2023]
Abstract
Electric field profile structure-especially its shear-is a natural order parameter for the edge plasma, and characterizes confinement regimes ranging from the H-mode (Wagner et al. 1982 Phys. Rev. Lett. 49, 1408-1412 (doi:10.1103/PhysRevLett.49.1408)) to the density limit (DL) (Greenwald et al. 1988 Nucl. Fusion 28, 2199-2207 (doi:10.1088/0029-5515/28/12/009)). The theoretical developments and lessons learned during 40 years of H-mode studies (Connor & Wilson 1999 Plasma Phys. Control. Fusion 42, R1-R74 (doi:10.1088/0741-3335/42/1/201); Wagner 2007 Plasma Phys. Control. Fusion 49, B1-B33 (doi:10.1088/0741-3335/49/12b/s01)) are applied to the shear layer collapse paradigm (Hong et al. 2017 Nucl. Fusion 58, 016041 (doi:10.1088/1741-4326/aa9626)) for the onset of DL phenomena. Results from recent experiments on edge shear layers and DL phenomenology are summarized and discussed in the light of L [Formula: see text] H transition physics. The theory of shear layer collapse is then developed. We demonstrate that shear layer physics captures both the well known current (Greenwald) scaling of the DL (Greenwald 2002 Plasma Phys. Control. Fusion 44, R27-R53 (doi:10.1088/0741-3335/44/8/201); Greenwald et al. 2014 Phys. Plasmas 21, 110501 (doi:10.1063/1.4901920)), as well as the emerging power scaling (Zanca, Sattin, JET Contributors 2019 Nucl. Fusion 59, 126011 (doi:10.1088/1741-4326/ab3b31)). The derivation of the power scaling theory exploits an existing model, originally developed for the L [Formula: see text] H transition (Diamond, Liang, Carreras, Terry 1994 Phys. Rev. Lett. 72, 2565-2568 (doi:10.1103/PhysRevLett.72.2565); Kim & Diamond 2003 Phys. Rev. Lett. 90, 185006 (doi:10.1103/PhysRevLett.90.185006)). We describe the enhanced particle transport events that occur following shear layer collapse. Open problems and future directions are discussed. This article is part of a discussion meeting issue 'H-mode transition and pedestal studies in fusion plasmas'.
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Affiliation(s)
- Patrick H Diamond
- Department of Physics, University of California San Diego, La Jolla, CA, USA
| | - Rameswar Singh
- Department of Physics, University of California San Diego, La Jolla, CA, USA
| | - Ting Long
- Center for Fusion Science, Southwestern Institute of Physics, Chengdu, People's Republic of China
| | - Rongjie Hong
- Department of Physics and Astronomy, University of California Los Angeles, CA, USA
| | - Rui Ke
- Center for Fusion Science, Southwestern Institute of Physics, Chengdu, People's Republic of China
| | - Zheng Yan
- Department of Engineering Physics, University of Wisconsin Madison, Madison, WI, USA
| | - Mingyun Cao
- Department of Physics, University of California San Diego, La Jolla, CA, USA
| | - George R Tynan
- Department of Mechanical and Aerospace Engineering, University of California San Diego, CA, USA
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2
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Warmer F, Tanaka K, Xanthopoulos P, Nunami M, Nakata M, Beidler CD, Bozhenkov SA, Beurskens MNA, Brunner KJ, Ford OP, Fuchert G, Funaba H, Geiger J, Gradic D, Ida K, Igami H, Kubo S, Langenberg A, Laqua HP, Lazerson S, Morisaki T, Osakabe M, Pablant N, Pasch E, Peterson B, Satake S, Seki R, Shimozuma T, Smith HM, Stange T, Stechow AV, Sugama H, Suzuki Y, Takahashi H, Tokuzawa T, Tsujimura T, Turkin Y, Wolf RC, Yamada I, Yanai R, Yasuhara R, Yokoyama M, Yoshimura Y, Yoshinuma M, Zhang D. Impact of Magnetic Field Configuration on Heat Transport in Stellarators and Heliotrons. PHYSICAL REVIEW LETTERS 2021; 127:225001. [PMID: 34889640 DOI: 10.1103/physrevlett.127.225001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 07/30/2021] [Accepted: 09/20/2021] [Indexed: 06/13/2023]
Abstract
We assess the magnetic field configuration in modern fusion devices by comparing experiments with the same heating power, between a stellarator and a heliotron. The key role of turbulence is evident in the optimized stellarator, while neoclassical processes largely determine the transport in the heliotron device. Gyrokinetic simulations elucidate the underlying mechanisms promoting stronger ion scale turbulence in the stellarator. Similar plasma performances in these experiments suggests that neoclassical and turbulent transport should both be optimized in next step reactor designs.
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Affiliation(s)
- Felix Warmer
- Max-Planck-Institut für Plasmaphysik, Wendelsteinstrasse 1, 17491 Greifswald, Germany
| | - K Tanaka
- National Institute for Fusion Science, National Institutes on Natural Sciences, Toki, 509-5292, Japan
- Kyushu University, Interdisciplinary Graduate School of Engineering Sciences, Plasma and Quantum Science and Engineering, Kasuga, Fukuoka 816-8580, Japan
| | - P Xanthopoulos
- Max-Planck-Institut für Plasmaphysik, Wendelsteinstrasse 1, 17491 Greifswald, Germany
| | - M Nunami
- National Institute for Fusion Science, National Institutes on Natural Sciences, Toki, 509-5292, Japan
- SOKENDAI (The Graduate University for Advanced Studies), Toki, Gifu 509-5292, Japan
- Nagoya University, Graduate School of Science, Nagoya 464-8603, Japan
| | - M Nakata
- National Institute for Fusion Science, National Institutes on Natural Sciences, Toki, 509-5292, Japan
- SOKENDAI (The Graduate University for Advanced Studies), Toki, Gifu 509-5292, Japan
| | - C D Beidler
- Max-Planck-Institut für Plasmaphysik, Wendelsteinstrasse 1, 17491 Greifswald, Germany
| | - S A Bozhenkov
- Max-Planck-Institut für Plasmaphysik, Wendelsteinstrasse 1, 17491 Greifswald, Germany
| | - M N A Beurskens
- Max-Planck-Institut für Plasmaphysik, Wendelsteinstrasse 1, 17491 Greifswald, Germany
| | - K J Brunner
- Max-Planck-Institut für Plasmaphysik, Wendelsteinstrasse 1, 17491 Greifswald, Germany
| | - O P Ford
- Max-Planck-Institut für Plasmaphysik, Wendelsteinstrasse 1, 17491 Greifswald, Germany
| | - G Fuchert
- Max-Planck-Institut für Plasmaphysik, Wendelsteinstrasse 1, 17491 Greifswald, Germany
| | - H Funaba
- National Institute for Fusion Science, National Institutes on Natural Sciences, Toki, 509-5292, Japan
| | - J Geiger
- Max-Planck-Institut für Plasmaphysik, Wendelsteinstrasse 1, 17491 Greifswald, Germany
| | - D Gradic
- Max-Planck-Institut für Plasmaphysik, Wendelsteinstrasse 1, 17491 Greifswald, Germany
| | - K Ida
- National Institute for Fusion Science, National Institutes on Natural Sciences, Toki, 509-5292, Japan
- SOKENDAI (The Graduate University for Advanced Studies), Toki, Gifu 509-5292, Japan
| | - H Igami
- National Institute for Fusion Science, National Institutes on Natural Sciences, Toki, 509-5292, Japan
| | - S Kubo
- National Institute for Fusion Science, National Institutes on Natural Sciences, Toki, 509-5292, Japan
- Nagoya University, Graduate School of Science, Nagoya 464-8603, Japan
| | - A Langenberg
- Max-Planck-Institut für Plasmaphysik, Wendelsteinstrasse 1, 17491 Greifswald, Germany
| | - H P Laqua
- Max-Planck-Institut für Plasmaphysik, Wendelsteinstrasse 1, 17491 Greifswald, Germany
| | - S Lazerson
- Max-Planck-Institut für Plasmaphysik, Wendelsteinstrasse 1, 17491 Greifswald, Germany
| | - T Morisaki
- National Institute for Fusion Science, National Institutes on Natural Sciences, Toki, 509-5292, Japan
- SOKENDAI (The Graduate University for Advanced Studies), Toki, Gifu 509-5292, Japan
| | - M Osakabe
- National Institute for Fusion Science, National Institutes on Natural Sciences, Toki, 509-5292, Japan
- SOKENDAI (The Graduate University for Advanced Studies), Toki, Gifu 509-5292, Japan
| | - N Pablant
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - E Pasch
- Max-Planck-Institut für Plasmaphysik, Wendelsteinstrasse 1, 17491 Greifswald, Germany
| | - B Peterson
- National Institute for Fusion Science, National Institutes on Natural Sciences, Toki, 509-5292, Japan
| | - S Satake
- National Institute for Fusion Science, National Institutes on Natural Sciences, Toki, 509-5292, Japan
- SOKENDAI (The Graduate University for Advanced Studies), Toki, Gifu 509-5292, Japan
| | - R Seki
- National Institute for Fusion Science, National Institutes on Natural Sciences, Toki, 509-5292, Japan
- SOKENDAI (The Graduate University for Advanced Studies), Toki, Gifu 509-5292, Japan
| | - T Shimozuma
- National Institute for Fusion Science, National Institutes on Natural Sciences, Toki, 509-5292, Japan
| | - H M Smith
- Max-Planck-Institut für Plasmaphysik, Wendelsteinstrasse 1, 17491 Greifswald, Germany
| | - T Stange
- Max-Planck-Institut für Plasmaphysik, Wendelsteinstrasse 1, 17491 Greifswald, Germany
| | - A V Stechow
- Max-Planck-Institut für Plasmaphysik, Wendelsteinstrasse 1, 17491 Greifswald, Germany
| | - H Sugama
- National Institute for Fusion Science, National Institutes on Natural Sciences, Toki, 509-5292, Japan
- SOKENDAI (The Graduate University for Advanced Studies), Toki, Gifu 509-5292, Japan
| | - Y Suzuki
- National Institute for Fusion Science, National Institutes on Natural Sciences, Toki, 509-5292, Japan
- SOKENDAI (The Graduate University for Advanced Studies), Toki, Gifu 509-5292, Japan
| | - H Takahashi
- National Institute for Fusion Science, National Institutes on Natural Sciences, Toki, 509-5292, Japan
- SOKENDAI (The Graduate University for Advanced Studies), Toki, Gifu 509-5292, Japan
| | - T Tokuzawa
- National Institute for Fusion Science, National Institutes on Natural Sciences, Toki, 509-5292, Japan
- SOKENDAI (The Graduate University for Advanced Studies), Toki, Gifu 509-5292, Japan
| | - T Tsujimura
- National Institute for Fusion Science, National Institutes on Natural Sciences, Toki, 509-5292, Japan
- SOKENDAI (The Graduate University for Advanced Studies), Toki, Gifu 509-5292, Japan
| | - Y Turkin
- Max-Planck-Institut für Plasmaphysik, Wendelsteinstrasse 1, 17491 Greifswald, Germany
| | - R C Wolf
- Max-Planck-Institut für Plasmaphysik, Wendelsteinstrasse 1, 17491 Greifswald, Germany
| | - I Yamada
- National Institute for Fusion Science, National Institutes on Natural Sciences, Toki, 509-5292, Japan
| | - R Yanai
- National Institute for Fusion Science, National Institutes on Natural Sciences, Toki, 509-5292, Japan
| | - R Yasuhara
- National Institute for Fusion Science, National Institutes on Natural Sciences, Toki, 509-5292, Japan
- SOKENDAI (The Graduate University for Advanced Studies), Toki, Gifu 509-5292, Japan
| | - M Yokoyama
- National Institute for Fusion Science, National Institutes on Natural Sciences, Toki, 509-5292, Japan
- SOKENDAI (The Graduate University for Advanced Studies), Toki, Gifu 509-5292, Japan
| | - Y Yoshimura
- National Institute for Fusion Science, National Institutes on Natural Sciences, Toki, 509-5292, Japan
| | - M Yoshinuma
- National Institute for Fusion Science, National Institutes on Natural Sciences, Toki, 509-5292, Japan
- SOKENDAI (The Graduate University for Advanced Studies), Toki, Gifu 509-5292, Japan
| | - D Zhang
- Max-Planck-Institut für Plasmaphysik, Wendelsteinstrasse 1, 17491 Greifswald, Germany
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Miyazawa J, Yamada H, Sakamoto R, Funaba H, Watanabe KY, Sakakibara S, Ida K, Goto M, Morisaki T, Murakami S, Inagaki S. Characteristics of the Global Energy Confinement and Central Pressure in LHD. FUSION SCIENCE AND TECHNOLOGY 2017. [DOI: 10.13182/fst10-a10790] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- J. Miyazawa
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - H. Yamada
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - R. Sakamoto
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - H. Funaba
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - K. Y. Watanabe
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - S. Sakakibara
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - K. Ida
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - M. Goto
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - T. Morisaki
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - S. Murakami
- Kyoto University, Department of Nuclear Engineering, Kyoto 606-8501, Japan
| | - S. Inagaki
- Research Institute for Applied Mechanics, Kyushu University, Kasuga 816-8580, Japan
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Tanaka K, Kawahata K, Tokuzawa T, Akiyama T, Yokoyama M, Shoji M, Michael CA, Vyacheslavov LN, Murakami S, Wakasa A, Mishchenko A, Muraoka K, Okajima S, Takenaga H. Particle Transport of LHD. FUSION SCIENCE AND TECHNOLOGY 2017. [DOI: 10.13182/fst10-a10795] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- K. Tanaka
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - K. Kawahata
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - T. Tokuzawa
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - T. Akiyama
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - M. Yokoyama
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - M. Shoji
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - C. A. Michael
- EURATOM/UAKEA Fusion Association, Culham Science Centre, Oxfordshire OX14 3DB, United Kingdom
| | | | - S. Murakami
- Kyoto University, Department of Nuclear Engineering, Kyoto 606-8501, Japan
| | - A. Wakasa
- Kyoto University, Department of Nuclear Engineering, Kyoto 606-8501, Japan
| | - A. Mishchenko
- Max Planck Institut für Plasmaphysik, EURATOM-Association, D-17491 Greifswald, Germany
| | - K. Muraoka
- Chubu University, School of Engineering, Kasugai 487-8501, Japan
| | - S. Okajima
- Chubu University, School of Engineering, Kasugai 487-8501, Japan
| | - H. Takenaga
- Japan Atomic Energy Agency, 801-1 Mukoyama, Naka 311-0193, Japan
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