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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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Zhang D, König R, Feng Y, Burhenn R, Brezinsek S, Jakubowski M, Buttenschön B, Niemann H, Pavone A, Krychowiak M, Kwak S, Svensson J, Gao Y, Pedersen TS, Alonso A, Baldzuhn J, Beidler CD, Biedermann C, Bozhenkov S, Brunner KJ, Damm H, Hirsch M, Giannone L, Drewelow P, Effenberg F, Fuchert G, Hammond KC, Höfel U, Killer C, Knauer J, Laqua HP, Laube R, Pablant N, Pasch E, Penzel F, Rahbarnia K, Reimold F, Thomsen H, Winters V, Wagner F, Klinger T. First Observation of a Stable Highly Dissipative Divertor Plasma Regime on the Wendelstein 7-X Stellarator. PHYSICAL REVIEW LETTERS 2019; 123:025002. [PMID: 31386539 DOI: 10.1103/physrevlett.123.025002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Indexed: 06/10/2023]
Abstract
For the first time, the optimized stellarator Wendelstein 7-X has operated with an island divertor. An operation regime in hydrogen was found in which the total plasma radiation approached the absorbed heating power without noticeable loss of stored energy. The divertor thermography recorded simultaneously a strong reduction of the heat load on all divertor targets, indicating almost complete power detachment. This operation regime was stably sustained over several energy confinement times until the preprogrammed end of the discharge. The plasma radiation is mainly due to oxygen and is located at the plasma edge. This plasma scenario is reproducible and robust at various heating powers, plasma densities, and gas fueling locations. These experimental results show that the island divertor concept actually works and displays good power dissipation potential, producing a promising exhaust concept for the stellarator reactor line.
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Affiliation(s)
- D Zhang
- Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany
| | - R König
- Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany
| | - Y Feng
- Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany
| | - R Burhenn
- Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany
| | - S Brezinsek
- Forschungszentrum Jülich GmbH, IEK-4 52425 Jülich, Germany
| | - M Jakubowski
- Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany
| | - B Buttenschön
- Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany
| | - H Niemann
- Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany
| | - A Pavone
- Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany
| | - M Krychowiak
- Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany
| | - S Kwak
- Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany
| | - J Svensson
- Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany
| | - Y Gao
- Forschungszentrum Jülich GmbH, IEK-4 52425 Jülich, Germany
| | - T S Pedersen
- Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany
| | - A Alonso
- Laboratorio Nacional de Fusion CIEMAT, 28040 Madrid, Spain
| | - J Baldzuhn
- Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany
| | - C D Beidler
- Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany
| | - C Biedermann
- Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany
| | - S Bozhenkov
- Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany
| | - K J Brunner
- Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany
| | - H Damm
- Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany
| | - M Hirsch
- Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany
| | - L Giannone
- Max-Planck-Institut für Plasmaphysik, 85748 Garching, Germany
| | - P Drewelow
- Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany
| | - F Effenberg
- University of Wisconsin, Madison, Wisconsin 53706, USA
| | - G Fuchert
- Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany
| | - K C Hammond
- Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany
| | - U Höfel
- Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany
| | - C Killer
- Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany
| | - J Knauer
- Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany
| | - H P Laqua
- Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany
| | - R Laube
- Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany
| | - N Pablant
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540, USA
| | - E Pasch
- Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany
| | - F Penzel
- Max-Planck-Institut für Plasmaphysik, 85748 Garching, Germany
| | - K Rahbarnia
- Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany
| | - F Reimold
- Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany
| | - H Thomsen
- Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany
| | - V Winters
- University of Wisconsin, Madison, Wisconsin 53706, USA
| | - F Wagner
- Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany
| | - T Klinger
- Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany
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3
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Initial Exploration of High-Field Pulsed Stellarator Approach to Ignition Experiments. JOURNAL OF FUSION ENERGY 2018. [DOI: 10.1007/s10894-018-0199-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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4
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Nakamura Y, Tamura N, Kobayashi M, Yoshimura S, Suzuki C, Yoshinuma M, Goto M, Motojima G, Nagaoka K, Tanaka K, Sakamoto R, Peterson B, Ida K, Osakabe M, Morisaki T. A comprehensive study on impurity behavior in LHD long pulse discharges. NUCLEAR MATERIALS AND ENERGY 2017. [DOI: 10.1016/j.nme.2016.11.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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5
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Mitarai O, Sagara A, Ohyabu N, Sakamoto R, Komori A, Motojima O. Stabilization of Unstable Low-Temperature and High-Density Operation in the Force-Free Helical Reactor. FUSION SCIENCE AND TECHNOLOGY 2017. [DOI: 10.13182/fst09-a9253] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Osamu Mitarai
- Tokai University, Kumamoto Campus, Liberal Arts Education Center 9-1-1 Toroku, Kumamoto 862-8652, Japan
| | - Akio Sagara
- National Institute for Fusion Science 322-6 Oroshi-cho, Toki 509-5292, Japan
| | - Nobuyoshi Ohyabu
- National Institute for Fusion Science 322-6 Oroshi-cho, Toki 509-5292, Japan
| | - Ryuichi Sakamoto
- National Institute for Fusion Science 322-6 Oroshi-cho, Toki 509-5292, Japan
| | - Akio Komori
- National Institute for Fusion Science 322-6 Oroshi-cho, Toki 509-5292, Japan
| | - Osamu Motojima
- National Institute for Fusion Science 322-6 Oroshi-cho, Toki 509-5292, Japan
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6
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Shoji M, Masuzaki S, Kobayashi M, Goto M, Morisaki T, Yamada H, Komori A, Iwamae A, Sakaue A. Investigation of the Helical Divertor Function and the Future Plan of a Closed Divertor for Efficient Particle Control in the LHD Plasma Periphery. FUSION SCIENCE AND TECHNOLOGY 2017. [DOI: 10.13182/fst10-04] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- M. Shoji
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki, Gifu 509-5292, Japan
| | - S. Masuzaki
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki, Gifu 509-5292, Japan
| | - M. Kobayashi
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki, Gifu 509-5292, Japan
| | - M. Goto
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki, Gifu 509-5292, Japan
| | - T. Morisaki
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki, Gifu 509-5292, Japan
| | - H. Yamada
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki, Gifu 509-5292, Japan
| | - A. Komori
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki, Gifu 509-5292, Japan
| | - A. Iwamae
- Department of Mechanical Engineering and Science, Graduate School of Engineering Kyoto University, Kyoto 606-8501, Japan
| | - A. Sakaue
- Department of Mechanical Engineering and Science, Graduate School of Engineering Kyoto University, Kyoto 606-8501, Japan
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7
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Sakamoto R, Yamada H, Kobayashi M, Miyazawa J, Ohdachi S, Morisaki T, Masuzaki S, Goto M, Funaba H, Yamada I, Ida K, Morita S, Peterson BJ, Ohyabu N, Komori A, Motojima O. Advanced Operational Regime with Internal Diffusion Barrier on LHD. FUSION SCIENCE AND TECHNOLOGY 2017. [DOI: 10.13182/fst10-a10793] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- R. Sakamoto
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - H. Yamada
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - M. Kobayashi
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - J. Miyazawa
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - S. Ohdachi
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - T. Morisaki
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - S. Masuzaki
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - M. Goto
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - H. Funaba
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - I. Yamada
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - K. Ida
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - S. Morita
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - B. J. Peterson
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - N. Ohyabu
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - A. Komori
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - O. Motojima
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
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8
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Masuzaki S, Ashikawa N, Nishimura K, Tokitani M, Hino T, Yamauchi Y, Nobuta Y, Yoshida N, Miyamoto M, Sagara A, Noda N, Yamada H, Komori A. Wall Conditioning in LHD. FUSION SCIENCE AND TECHNOLOGY 2017. [DOI: 10.13182/fst10-a10816] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- S. Masuzaki
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - N. Ashikawa
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - K. Nishimura
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - M. Tokitani
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - T. Hino
- Hokkaido University, Sapporo 060-8628, Japan
| | - Y. Yamauchi
- Hokkaido University, Sapporo 060-8628, Japan
| | - Y. Nobuta
- Hokkaido University, Sapporo 060-8628, Japan
| | - N. Yoshida
- Research Institute for Applied Mechanics, Kyushu University, Fukuoka 816-8580, Japan
| | | | - A. Sagara
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - N. Noda
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - H. Yamada
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - A. Komori
- National Institute for Fusion Science, Toki 509-5292, Japan
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9
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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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10
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Goto M, Morita S, Zhou HY, Dong CF. Passive Spectroscopy in Visible, VUV, and X-Ray Ranges for LHD Diagnostics. FUSION SCIENCE AND TECHNOLOGY 2017. [DOI: 10.13182/fst10-a10825] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- M. Goto
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - S. Morita
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - H. Y. Zhou
- Graduate University for Advanced Studies, Department of Fusion Science, Toki, Gifu 509-5292, Japan
| | - C. F. Dong
- Graduate University for Advanced Studies, Department of Fusion Science, Toki, Gifu 509-5292, Japan
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11
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Miyazawa J, Masuzaki S, Sakamoto R, Peterson BJ, Tamura N, Goto M, Kobayashi M, Shoji M, Akiyama T, Yamada H. Density Limits for the Core and Edge Plasmas Related to the Local Temperatures in LHD. FUSION SCIENCE AND TECHNOLOGY 2017. [DOI: 10.13182/fst10-a10807] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [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
| | - S. Masuzaki
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - R. Sakamoto
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - B. J. Peterson
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - N. Tamura
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - M. Goto
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - M. Kobayashi
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - M. Shoji
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - T. Akiyama
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
| | - H. Yamada
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
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12
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Morisaki T, Masuzaki S, Sakamoto R, Kobayashi M, Ohyabu N, Yamada H, Komori A. Local Island Divertor Experiment. FUSION SCIENCE AND TECHNOLOGY 2017. [DOI: 10.13182/fst10-a10810] [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)
- T. Morisaki
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - S. Masuzaki
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - R. Sakamoto
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - M. Kobayashi
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - N. Ohyabu
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - H. Yamada
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - A. Komori
- National Institute for Fusion Science, Toki 509-5292, Japan
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13
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Komori A, Yamada H, Imagawa S, Kaneko O, Kawahata K, Mutoh K, Ohyabu N, Takeiri Y, Ida K, Mito T, Nagayama Y, Sakakibara S, Sakamoto R, Shimozuma T, Watanabe KY, Motojima O. Goal and Achievements of Large Helical Device Project. FUSION SCIENCE AND TECHNOLOGY 2017. [DOI: 10.13182/fst58-1] [Citation(s) in RCA: 112] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- A. Komori
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - H. Yamada
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - S. Imagawa
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - O. Kaneko
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - K. Kawahata
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - K. Mutoh
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - N. Ohyabu
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - Y. Takeiri
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - K. Ida
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - T. Mito
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - Y. Nagayama
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - S. Sakakibara
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - R. Sakamoto
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - T. Shimozuma
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - K. Y. Watanabe
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - O Motojima
- National Institute for Fusion Science, Toki 509-5292, Japan
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14
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Yamada H, Kawahata K, Mutoh T, Ohyabu N, Takeiri Y, Imagawa S, Ida K, Mito T, Nagayama Y, Shimozuma T, Watanabe KY, Kobayashi M, Kumazawa R, Masuzaki S, Morisaki T, Miyazawa J, Nagaoka K, Narushima Y, Sakakibara S, Sakamoto R, Toi K, Yokoyama M, Kaneko O, Komori A, Motojima O. Progress in the Integrated Development of the Helical System. FUSION SCIENCE AND TECHNOLOGY 2017. [DOI: 10.13182/fst10-a10789] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- H. Yamada
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - K. Kawahata
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - T. Mutoh
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - N. Ohyabu
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - Y. Takeiri
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - S. Imagawa
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - K. Ida
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - T. Mito
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - Y. Nagayama
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - T. Shimozuma
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - K. Y. Watanabe
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - M. Kobayashi
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - R. Kumazawa
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - S. Masuzaki
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - T. Morisaki
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - J. Miyazawa
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - K. Nagaoka
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - Y. Narushima
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - S. Sakakibara
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - R. Sakamoto
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - K. Toi
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - M. Yokoyama
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - O. Kaneko
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - A. Komori
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - O. Motojima
- National Institute for Fusion Science, Toki 509-5292, Japan
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15
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Sheffield J, Spong DA. Catalyzed D-D Stellarator Reactor. FUSION SCIENCE AND TECHNOLOGY 2016. [DOI: 10.13182/fst15-161] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
| | - Donald A Spong
- Oak Ridge National Laboratory, Fusion Materials and Nuclear Science Division, One Bethel Valley Road, Oak Ridge, Tennessee 37831-6169
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16
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Sakamoto R, Yamada H. Fueling requirements of super-high-density plasmas towards innovative ignition regime. FUSION ENGINEERING AND DESIGN 2014. [DOI: 10.1016/j.fusengdes.2014.05.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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17
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Sakamoto R, Motojima G, Hayashi H, Inoue T, Ito Y, Ogawa H, Takami S, Yokota M, Yamada H. Twenty barrel in situ pipe gun type solid hydrogen pellet injector for the Large Helical Device. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2013; 84:083504. [PMID: 24007062 DOI: 10.1063/1.4816823] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
A 20 barrel solid hydrogen pellet injector, which is able to inject 20 cylindrical pellets with a diameter and length of between 3.0 and 3.8 mm at the velocity of 1200 m/s, has been developed for the purpose of direct core fueling in LHD (Large Helical Device). The in situ pipe gun concept with the use of compact cryo-coolers enables stable operation as a fundamental facility in plasma experiments. The combination of the two types of pellet injection timing control modes, i.e., pre-programing mode and real-time control mode, allows the build-up and sustainment of high density plasma around the density limit. The pellet injector has demonstrated stable operation characteristics during the past three years of LHD experiments.
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Affiliation(s)
- Ryuichi Sakamoto
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
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18
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Igami H, Yoshimura Y, Takahashi H, Shimozuma T, Kubo S, Idei H, Nishiura M, Ogasawara S, Makino R, Ohdachi S, Ida K, Yoshinuma M, Ido T, Shimizu A, Tamura N, Inagaki S, Mutoh T. Progress of ECRH by EBW in over-dense plasmas and controlling the confinement regime by ECCD with high power launching in LHD. EPJ WEB OF CONFERENCES 2012. [DOI: 10.1051/epjconf/20123202006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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19
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Ashikawa N, Hirooka Y, Tsuchiya H, Chung KS, Masuzaki S, Nagayama Y. Surface chemical/binding reaction of coated Li layer by lithium vapor injectors in LIGHT-1. FUSION ENGINEERING AND DESIGN 2010. [DOI: 10.1016/j.fusengdes.2010.09.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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20
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Hirooka Y. A review of plasma–wall boundary effects on core confinement and lithium applications to boundary-controlled magnetic fusion experiments. FUSION ENGINEERING AND DESIGN 2010. [DOI: 10.1016/j.fusengdes.2010.04.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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21
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22
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Masuzaki S, Shoji M, Tokitani M, Murase T, Kobayashi M, Morisaki T, Yonezu H, Sakamoto R, Yamada H, Komori A. Design and installation of the closed helical divertor in LHD. FUSION ENGINEERING AND DESIGN 2010. [DOI: 10.1016/j.fusengdes.2010.08.048] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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23
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Itoh K, Sugama H, Watanabe TH, Yamagishi O, Toda S, Kasuya N, Kanno R, Nunami M. Microinstabilities, Turbulent Transport, and Structure Formation in Helical Plasmas. FUSION SCIENCE AND TECHNOLOGY 2010. [DOI: 10.13182/fst10-a10812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- K. Itoh
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - H. Sugama
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - T.-H. Watanabe
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - O. Yamagishi
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - S. Toda
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - N. Kasuya
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - R. Kanno
- National Institute for Fusion Science, Toki 509-5292, Japan
| | - M. Nunami
- National Institute for Fusion Science, Toki 509-5292, Japan
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24
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Ichiguchi K, Miura H, Mizuguchi N, Suzuki Y, Nakajima N, Nakamura Y. Theoretical MHD Analyses of LHD Plasmas. FUSION SCIENCE AND TECHNOLOGY 2010. [DOI: 10.13182/fst10-a10811] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- K. Ichiguchi
- National Institute for Fusion Science, Oroshi-cho 322-6, Toki 509-5292, Japan
| | - H. Miura
- National Institute for Fusion Science, Oroshi-cho 322-6, Toki 509-5292, Japan
| | - N. Mizuguchi
- National Institute for Fusion Science, Oroshi-cho 322-6, Toki 509-5292, Japan
| | - Y. Suzuki
- National Institute for Fusion Science, Oroshi-cho 322-6, Toki 509-5292, Japan
| | - N. Nakajima
- National Institute for Fusion Science, Oroshi-cho 322-6, Toki 509-5292, Japan
| | - Y. Nakamura
- Kyoto University, Graduate School of Energy Science, Gokasho, Uji, Kyoto 611-0011, Japan
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25
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Shoji M, Kobayashi M, Masuzaki S, Sagara A, Yamada H, Komori A. Design of a Closed Helical Divertor in LHD and the Prospect for Helical Fusion Reactors. FUSION SCIENCE AND TECHNOLOGY 2009. [DOI: 10.13182/fst09-a9041] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Mamoru Shoji
- National Institute for Fusion Science: Toki, Gifu, Japan,509-5292
| | | | - Suguru Masuzaki
- National Institute for Fusion Science: Toki, Gifu, Japan,509-5292
| | - Akio Sagara
- National Institute for Fusion Science: Toki, Gifu, Japan,509-5292
| | - Hiroshi Yamada
- National Institute for Fusion Science: Toki, Gifu, Japan,509-5292
| | - Akio Komori
- National Institute for Fusion Science: Toki, Gifu, Japan,509-5292
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26
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Yamada H, Imagawa S, Takeiri Y, Kaneko O, Mutoh T, Mito T, Chikaraishi H, Hamaguchi S, Ida K, Igami H, Ikeda K, Kasahara H, Kobayashi M, Kubo S, Kumazawa R, Maekawa R, Masuzaki S, Miyazawa J, Morisaki T, Morita S, Nagaoka K, Nakamura Y, Narushima Y, Osakabe M, Saito K, Sakakibara S, Sakamoto R, Seki T, Shimozuma T, Shoji M, Suzuki Y, Takahata K, Tamura H, Tsumori K, Watanabe K, Yamada S, Yanagi N, Yoshimura Y, Kawahata K, Ohyabu N, Komori A, Motojima O. 10 years of engineering and physics achievements by the Large Helical Device project. FUSION ENGINEERING AND DESIGN 2009. [DOI: 10.1016/j.fusengdes.2009.01.068] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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27
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28
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Akiyama T, Kawahata K, Tanaka K, Okajima S, Nakayama K. Short wavelength far infrared laser polarimeter with silicon photoelastic modulators. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2008; 79:10E720. [PMID: 19044537 DOI: 10.1063/1.2957936] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A short wavelength far infrared laser whose wavelength lambda is about 50 microm is preferable for a polarimeter and an interferometer for high density operations in the Large Helical Device (LHD) and on future large fusion devices such as ITER. This is because the beam bending effect (proportional to lambda(2)) in a plasma, which causes fringe jump errors, is small and the Faraday and the Cotton-Mouton effects are moderate. We have developed a polarimeter with highly resistive silicon photoelastic modulators (PEMs) for the CH(3)OD laser (lambda=57.2 and 47.7 microm). We performed bench tests of the polarimeter with a dual PEM and demonstrated the feasibility for the polarimeter. Good linearity between actual and evaluated polarization angles is achieved with an angular resolution of 0.05 degrees and a temporal resolution of 1 ms. The baseline drift of the polarization angle is about 0.1 degrees for 1000 s.
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Affiliation(s)
- T Akiyama
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu 509-5292, Japan.
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29
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Kawahata K, Akiyama T, Tanaka K, Nakayama K, Okajima S. Development of terahertz laser diagnostics for electron density measurements. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2008; 79:10E707. [PMID: 19044525 DOI: 10.1063/1.2971976] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A two color laser interferometer using terahertz laser sources is under development for high performance operation on the large helical device and for future burning plasma experiments such as ITER. Through investigation of terahertz laser sources, we have achieved high power simultaneous oscillations at 57.2 and 47.6 microm of a CH(3)OD laser pumped by a cw 9R(8) CO(2) laser line. The laser wavelength around 50 microm is the optimum value for future fusion devices from the consideration of the beam refraction effect and signal-to-noise ratio for an expected phase shift due to plasma. In this article, recent progress of the terahertz laser diagnostics, especially in mechanical vibration compensation by using a two color laser operation and terahertz laser beam transmission through a dielectric waveguide, will be presented.
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Affiliation(s)
- K Kawahata
- National Institute for Fusion Science, Toki 509-5292, Japan.
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30
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Nagayama Y, Emoto M, Nakanishi H, Sudo S, Imazu S, Inagaki S, Iwata C, Kojima M, Nonomura M, Ohsuna M, Tsuda K, Yoshida M, Chikaraishi H, Funaba H, Horiuchi R, Ishiguro S, Ito Y, Kubo S, Mase A, Mito T, Miyazawa J, Mutoh T, Nakamura Y, Saito K, Sakamoto R, Seki T, Shoji M, Takami S, Watanabe T, Yamamoto T, Komori A, Motojima O. Control, data acquisition, data analysis and remote participation in LHD. FUSION ENGINEERING AND DESIGN 2008. [DOI: 10.1016/j.fusengdes.2007.10.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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31
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Kobayashi M, Ohyabu N, Mutoh T, Kumazawa R, Feng Y, Shoji M, Morisaki T, Masuzaki S, Sagara A, Sakamoto R, Seki T, Miyazawa J, Watanabe T, Goto M, Ideda K, Kasahara H, Morita S, Peterson BJ, Ashikawa N, Saito K, Sakakibara S, Tokuzawa T, Nakamura Y, Narihara K, Yamada I, Yamada H, Komori A, Motojima O. Edge Transport Control with the Local Island Divertor and Recent Progress in LHD. FUSION SCIENCE AND TECHNOLOGY 2007. [DOI: 10.13182/fst07-a1549] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- M. Kobayashi
- National Institute for Fusion Science, Oroshi-cho 322-6, Toki city, 509-5292, Japan
| | - N. Ohyabu
- National Institute for Fusion Science, Oroshi-cho 322-6, Toki city, 509-5292, Japan
| | - T. Mutoh
- National Institute for Fusion Science, Oroshi-cho 322-6, Toki city, 509-5292, Japan
| | - R. Kumazawa
- National Institute for Fusion Science, Oroshi-cho 322-6, Toki city, 509-5292, Japan
| | - Y. Feng
- Max-Planck-Institute fuer Plasmaphysik, Teilinstitut Greifswald, Euratom Association, 17491 Greifswald, Germany
| | - M. Shoji
- National Institute for Fusion Science, Oroshi-cho 322-6, Toki city, 509-5292, Japan
| | - T. Morisaki
- National Institute for Fusion Science, Oroshi-cho 322-6, Toki city, 509-5292, Japan
| | - S. Masuzaki
- National Institute for Fusion Science, Oroshi-cho 322-6, Toki city, 509-5292, Japan
| | - A. Sagara
- National Institute for Fusion Science, Oroshi-cho 322-6, Toki city, 509-5292, Japan
| | - R. Sakamoto
- National Institute for Fusion Science, Oroshi-cho 322-6, Toki city, 509-5292, Japan
| | - T. Seki
- National Institute for Fusion Science, Oroshi-cho 322-6, Toki city, 509-5292, Japan
| | - J. Miyazawa
- National Institute for Fusion Science, Oroshi-cho 322-6, Toki city, 509-5292, Japan
| | - T. Watanabe
- National Institute for Fusion Science, Oroshi-cho 322-6, Toki city, 509-5292, Japan
| | - M. Goto
- National Institute for Fusion Science, Oroshi-cho 322-6, Toki city, 509-5292, Japan
| | - K. Ideda
- National Institute for Fusion Science, Oroshi-cho 322-6, Toki city, 509-5292, Japan
| | - H. Kasahara
- National Institute for Fusion Science, Oroshi-cho 322-6, Toki city, 509-5292, Japan
| | - S. Morita
- National Institute for Fusion Science, Oroshi-cho 322-6, Toki city, 509-5292, Japan
| | - B. J. Peterson
- National Institute for Fusion Science, Oroshi-cho 322-6, Toki city, 509-5292, Japan
| | - N. Ashikawa
- National Institute for Fusion Science, Oroshi-cho 322-6, Toki city, 509-5292, Japan
| | - K. Saito
- National Institute for Fusion Science, Oroshi-cho 322-6, Toki city, 509-5292, Japan
| | - S. Sakakibara
- National Institute for Fusion Science, Oroshi-cho 322-6, Toki city, 509-5292, Japan
| | - T. Tokuzawa
- National Institute for Fusion Science, Oroshi-cho 322-6, Toki city, 509-5292, Japan
| | - Y. Nakamura
- National Institute for Fusion Science, Oroshi-cho 322-6, Toki city, 509-5292, Japan
| | - K. Narihara
- National Institute for Fusion Science, Oroshi-cho 322-6, Toki city, 509-5292, Japan
| | - I. Yamada
- National Institute for Fusion Science, Oroshi-cho 322-6, Toki city, 509-5292, Japan
| | - H. Yamada
- National Institute for Fusion Science, Oroshi-cho 322-6, Toki city, 509-5292, Japan
| | - A. Komori
- National Institute for Fusion Science, Oroshi-cho 322-6, Toki city, 509-5292, Japan
| | - O. Motojima
- National Institute for Fusion Science, Oroshi-cho 322-6, Toki city, 509-5292, Japan
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