1
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Ding S, Garofalo AM, Wang HQ, Weisberg DB, Li ZY, Jian X, Eldon D, Victor BS, Marinoni A, Hu QM, Carvalho IS, Odstrčil T, Wang L, Hyatt AW, Osborne TH, Gong XZ, Qian JP, Huang J, McClenaghan J, Holcomb CT, Hanson JM. A high-density and high-confinement tokamak plasma regime for fusion energy. Nature 2024:10.1038/s41586-024-07313-3. [PMID: 38658758 DOI: 10.1038/s41586-024-07313-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 03/14/2024] [Indexed: 04/26/2024]
Abstract
The tokamak approach, utilizing a toroidal magnetic field configuration to confine a hot plasma, is one of the most promising designs for developing reactors that can exploit nuclear fusion to generate electrical energy1,2. To reach the goal of an economical reactor, most tokamak reactor designs3-10 simultaneously require reaching a plasma line-averaged density above an empirical limit-the so-called Greenwald density11-and attaining an energy confinement quality better than the standard high-confinement mode12,13. However, such an operating regime has never been verified in experiments. In addition, a long-standing challenge in the high-confinement mode has been the compatibility between a high-performance core and avoiding large, transient edge perturbations that can cause very high heat loads on the plasma-facing-components in tokamaks. Here we report the demonstration of stable tokamak plasmas with a line-averaged density approximately 20% above the Greenwald density and an energy confinement quality of approximately 50% better than the standard high-confinement mode, which was realized by taking advantage of the enhanced suppression of turbulent transport granted by high density-gradients in the high-poloidal-beta scenario14,15. Furthermore, our experimental results show an integration of very low edge transient perturbations with the high normalized density and confinement core. The operating regime we report supports some critical requirements in many fusion reactor designs all over the world and opens a potential avenue to an operating point for producing economically attractive fusion energy.
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Affiliation(s)
- S Ding
- General Atomics, San Diego, CA, USA.
| | | | - H Q Wang
- General Atomics, San Diego, CA, USA
| | | | - Z Y Li
- General Atomics, San Diego, CA, USA
| | - X Jian
- General Atomics, San Diego, CA, USA
| | - D Eldon
- General Atomics, San Diego, CA, USA
| | - B S Victor
- Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - A Marinoni
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Q M Hu
- Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ, USA
| | | | | | - L Wang
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, China
| | | | | | - X Z Gong
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, China
| | - J P Qian
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, China
| | - J Huang
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, China
| | | | - C T Holcomb
- Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - J M Hanson
- Department of Applied Mathematics and Applied Physics, Columbia University, New York, NY, USA
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2
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Wang L, Wang HQ, Ding S, Garofalo AM, Gong XZ, Eldon D, Guo HY, Leonard AW, Hyatt AW, Qian JP, Weisberg DB, McClenaghan J, Fenstermacher ME, Lasnier CJ, Watkins JG, Shafer MW, Xu GS, Huang J, Ren QL, Buttery RJ, Humphreys DA, Thomas DM, Zhang B, Liu JB. Integration of full divertor detachment with improved core confinement for tokamak fusion plasmas. Nat Commun 2021; 12:1365. [PMID: 33649306 PMCID: PMC7921092 DOI: 10.1038/s41467-021-21645-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 01/29/2021] [Indexed: 11/24/2022] Open
Abstract
Divertor detachment offers a promising solution to the challenge of plasma-wall interactions for steady-state operation of fusion reactors. Here, we demonstrate the excellent compatibility of actively controlled full divertor detachment with a high-performance (βN ~ 3, H98 ~ 1.5) core plasma, using high-βp (poloidal beta, βp > 2) scenario characterized by a sustained core internal transport barrier (ITB) and a modest edge transport barrier (ETB) in DIII-D tokamak. The high-βp high-confinement scenario facilitates divertor detachment which, in turn, promotes the development of an even stronger ITB at large radius with a weaker ETB. This self-organized synergy between ITB and ETB, leads to a net gain in energy confinement, in contrast to the net confinement loss caused by divertor detachment in standard H-modes. These results show the potential of integrating excellent core plasma performance with an efficient divertor solution, an essential step towards steady-state operation of reactor-grade plasmas.
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Affiliation(s)
- L Wang
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, China
| | - H Q Wang
- General Atomics, San Diego, CA, USA.
| | - S Ding
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, China
- Oak Ridge Associated Universities, Oak Ridge, TN, USA
| | | | - X Z Gong
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, China
| | - D Eldon
- General Atomics, San Diego, CA, USA
| | - H Y Guo
- General Atomics, San Diego, CA, USA
| | | | | | - J P Qian
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, China
| | | | | | | | - C J Lasnier
- Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - J G Watkins
- Sandia National Laboratories, Livermore, CA, USA
| | - M W Shafer
- Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - G S Xu
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, China
| | - J Huang
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, China
| | - Q L Ren
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, China
| | | | | | | | - B Zhang
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, China
| | - J B Liu
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, China
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3
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Austin ME, Marinoni A, Walker ML, Brookman MW, deGrassie JS, Hyatt AW, McKee GR, Petty CC, Rhodes TL, Smith SP, Sung C, Thome KE, Turnbull AD. Achievement of Reactor-Relevant Performance in Negative Triangularity Shape in the DIII-D Tokamak. Phys Rev Lett 2019; 122:115001. [PMID: 30951344 DOI: 10.1103/physrevlett.122.115001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 01/21/2019] [Indexed: 06/09/2023]
Abstract
Plasma discharges with a negative triangularity (δ=-0.4) shape have been created in the DIII-D tokamak with a significant normalized beta (β_{N}=2.7) and confinement characteristic of the high confinement mode (H_{98y2}=1.2) despite the absence of an edge pressure pedestal and no edge localized modes (ELMs). These inner-wall-limited plasmas have a similar global performance as a positive triangularity (δ=+0.4) ELMing H-mode discharge with the same plasma current, elongation and cross sectional area. For cases both of dominant electron cyclotron heating with T_{e}/T_{i}>1 and dominant neutral beam injection heating with T_{e}/T_{i}=1, turbulent fluctuations over radii 0.5<ρ<0.9 were reduced by 10-50% in the negative triangularity shape compared to the matching positive triangularity shape, depending on the radius and conditions.
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Affiliation(s)
- M E Austin
- The University of Texas at Austin, Austin, Texas 78712, USA
| | - A Marinoni
- MIT-Plasma Science and Fusion Center, Cambridge, Massachusetts 02139, USA
| | - M L Walker
- General Atomics, San Diego, California 92186, USA
| | - M W Brookman
- General Atomics, San Diego, California 92186, USA
| | | | - A W Hyatt
- General Atomics, San Diego, California 92186, USA
| | - G R McKee
- University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - C C Petty
- General Atomics, San Diego, California 92186, USA
| | - T L Rhodes
- University of California-Los Angeles, Los Angeles, California 90095, USA
| | - S P Smith
- General Atomics, San Diego, California 92186, USA
| | - C Sung
- Lam Research Corp., Fremont, California 94538, USA
| | - K E Thome
- General Atomics, San Diego, California 92186, USA
| | - A D Turnbull
- General Atomics, San Diego, California 92186, USA
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4
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Najmabadi F, Conn RW, Bathke CG, Bromberg L, Cheng ET, Cohn DR, Cooke PIH, Creedon RL, Ehst DA, Evans K, Ghoniem NM, Grotz SP, Hasan MZ, Hogan JT, Herring JS, Hyatt AW, Ibrahim E, Jardin SA, Kessel C, Klasky M, Krakowski RA, Kunugi T, Leuer JA, Mandrekas J, Martin RC, Mau TK, Miller RL, Peng YKM, Reid RL, Santarius JF, Schaffer MJ, Schultz J, Schultz KR, Schwartz J, Sharafat S, Singer CE, Snead L, Steiner D, Strickler DJ, Sze DK, Valenti M, Ward DJ, Williams JEC, Wittenberg LJ, Wong CPC. The ARIES-I Tokamak Reactor Study†. ACTA ACUST UNITED AC 2017. [DOI: 10.13182/fst91-a29440] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
| | - R. W. Conn
- University of California, Los Angeles, CA,
| | | | - L. Bromberg
- Massachusetts Institute of Technology, Cambridge, MA
| | | | - D. R. Cohn
- Massachusetts Institute of Technology, Cambridge, MA
| | | | | | - D. A. Ehst
- Argonne National Laboratory, Argonne, IL,
| | - K. Evans
- Argonne National Laboratory, Argonne, IL,
| | | | | | | | - J. T. Hogan
- Oak Ridge National Laboratory, Oak Ridge, TN,
| | - J. S. Herring
- Idaho National Engineering Laboratory, Idaho Falls, ID
| | | | - E. Ibrahim
- University of California, Los Angeles, CA,
| | - S. A. Jardin
- Princeton Plasma Physics Laboratory, Princeton, NJ
| | - C. Kessel
- Princeton Plasma Physics Laboratory, Princeton, NJ
| | - M. Klasky
- Rensselaer Polytechnic Institute, Troy, NY,
| | | | - T. Kunugi
- University of California, Los Angeles, CA,
| | | | | | | | - T-K. Mau
- University of California, Los Angeles, CA,
| | | | | | - R. L. Reid
- Oak Ridge National Laboratory, Oak Ridge, TN,
| | | | | | - J. Schultz
- Massachusetts Institute of Technology, Cambridge, MA
| | | | - J. Schwartz
- Massachusetts Institute of Technology, Cambridge, MA
| | | | | | - L. Snead
- Rensselaer Polytechnic Institute, Troy, NY,
| | - D. Steiner
- Rensselaer Polytechnic Institute, Troy, NY,
| | | | - D-K. Sze
- Argonne National Laboratory, Argonne, IL,
| | - M. Valenti
- Rensselaer Polytechnic Institute, Troy, NY,
| | - D. J. Ward
- Princeton Plasma Physics Laboratory, Princeton, NJ
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5
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Jackson GL, Austin ME, deGRASSIE JS, Hyatt AW, Lohr JM, Luce TC, Prater R, West WP. Plasma Initiation and Start-Up Studies in the DIII-D Tokamak with Second-Harmonic EC Assist. Fusion Science and Technology 2017. [DOI: 10.13182/fst10-a9266] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- G. L. Jackson
- General Atomics, P.O. Box 85608 San Diego, California 92186-5608
| | - M. E. Austin
- General Atomics, P.O. Box 85608 San Diego, California 92186-5608
| | - J. S. deGRASSIE
- General Atomics, P.O. Box 85608 San Diego, California 92186-5608
| | - A. W. Hyatt
- General Atomics, P.O. Box 85608 San Diego, California 92186-5608
| | - J. M. Lohr
- General Atomics, P.O. Box 85608 San Diego, California 92186-5608
| | - T. C. Luce
- General Atomics, P.O. Box 85608 San Diego, California 92186-5608
| | - R. Prater
- General Atomics, P.O. Box 85608 San Diego, California 92186-5608
| | - W. P. West
- General Atomics, P.O. Box 85608 San Diego, California 92186-5608
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6
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Humphreys DA, Deranian RD, Ferron JR, Hyatt AW, Johnson RD, Khayrutdinov RR, La Haye RJ, Leuer JA, Penaflor BG, Scoville JT, Walker ML, Welander AS. Integrated Plasma Control in DIII-D. Fusion Science and Technology 2017. [DOI: 10.13182/fst05-a1075] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- D. A. Humphreys
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608
| | - R. D. Deranian
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608
| | - J. R. Ferron
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608
| | - A. W. Hyatt
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608
| | - R. D. Johnson
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608
| | | | - R. J. La Haye
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608
| | - J. A. Leuer
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608
| | - B. G. Penaflor
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608
| | - J. T. Scoville
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608
| | - M. L. Walker
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608
| | - A. S. Welander
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608
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7
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Wade MR, Luce TC, Jayakumar J, Politzer PA, Petty CC, Murakami M, Ferron JR, Hyatt AW, Sips ACC. Hybrid Scenario Development in DIII-D. Fusion Science and Technology 2017. [DOI: 10.13182/fst05-a1071] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- M. R. Wade
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608
| | - T. C. Luce
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608
| | - J. Jayakumar
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608
| | - P. A. Politzer
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608
| | - C. C. Petty
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608
| | - M. Murakami
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608
| | - J. R. Ferron
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608
| | - A. W. Hyatt
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608
| | - A. C. C. Sips
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608
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8
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Leuer JA, Xiao BJ, Humphreys DA, Walker ML, Hyatt AW, Jackson GL, Mueller D, Penaflor BG, Piglowski DA, Johnson RD, Welander AS, Yuan QP, Wang HZ, Luo JR. Tokamak Start-Up Modeling and Design for EAST First Plasma Campaign. Fusion Science and Technology 2017. [DOI: 10.13182/fst10-a9268] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- J. A. Leuer
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608
| | - B. J. Xiao
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, China
| | - D. A. Humphreys
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608
| | - M. L. Walker
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608
| | - A. W. Hyatt
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608
| | - G. L. Jackson
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608
| | - D. Mueller
- Princeton Plasma Physics Laboratory, Princeton, New Jersey
| | - B. G. Penaflor
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608
| | - D. A. Piglowski
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608
| | - R. D. Johnson
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608
| | - A. S. Welander
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608
| | - Q. P. Yuan
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, China
| | - H. Z. Wang
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, China
| | - J. R. Luo
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, China
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9
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Yang HL, Kwak JG, Oh YK, Park KR, Kim WC, Lee SG, Kim JY, Bae YS, Park YM, Kim HK, Chu Y, Park MK, Kim JS, In SR, Joung SH, Choe WH, Park HK, Hwang YS, Na YS, Park JG, Ahn JW, Park YS, Kwon M, Leuer JA, Eidietis NW, Hyatt AW, Walker M, Gorelov Y, Lohr J, Mueller D, Grisham LR, Sabbagh SA, Watanabe K, Inoue T, Sakamoto K, Oda Y, Kajiwara K, Ellis R, Hosea J, Delpech L, Hoang TT, Litaudon X, Namkung W, Cho MH. Overview of KSTAR Results in Phase-I Operation. Fusion Science and Technology 2017. [DOI: 10.13182/fst13-a19130] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- H. L. Yang
- National Fusion Research Institute, 113 Gwahangno, Yusung-Gu, Daejeon, 305-333, Korea
| | - J. G. Kwak
- National Fusion Research Institute, 113 Gwahangno, Yusung-Gu, Daejeon, 305-333, Korea
| | - Y. K. Oh
- National Fusion Research Institute, 113 Gwahangno, Yusung-Gu, Daejeon, 305-333, Korea
| | - K. R. Park
- National Fusion Research Institute, 113 Gwahangno, Yusung-Gu, Daejeon, 305-333, Korea
| | - W. C. Kim
- National Fusion Research Institute, 113 Gwahangno, Yusung-Gu, Daejeon, 305-333, Korea
| | - S. G. Lee
- National Fusion Research Institute, 113 Gwahangno, Yusung-Gu, Daejeon, 305-333, Korea
| | - J. Y. Kim
- National Fusion Research Institute, 113 Gwahangno, Yusung-Gu, Daejeon, 305-333, Korea
| | - Y. S. Bae
- National Fusion Research Institute, 113 Gwahangno, Yusung-Gu, Daejeon, 305-333, Korea
| | - Y. M. Park
- National Fusion Research Institute, 113 Gwahangno, Yusung-Gu, Daejeon, 305-333, Korea
| | - H. K. Kim
- National Fusion Research Institute, 113 Gwahangno, Yusung-Gu, Daejeon, 305-333, Korea
| | - Y. Chu
- National Fusion Research Institute, 113 Gwahangno, Yusung-Gu, Daejeon, 305-333, Korea
| | - M. K. Park
- National Fusion Research Institute, 113 Gwahangno, Yusung-Gu, Daejeon, 305-333, Korea
| | - J. S. Kim
- National Fusion Research Institute, 113 Gwahangno, Yusung-Gu, Daejeon, 305-333, Korea
| | - S. R. In
- Korea Atomic Energy Research Insititute, Daeduk-Daero 989-111, Yuseong-gu, Daejeon, 305-353, Korea
| | - S. H. Joung
- Korea Atomic Energy Research Insititute, Daeduk-Daero 989-111, Yuseong-gu, Daejeon, 305-353, Korea
| | - W. H. Choe
- Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701, Korea
| | - H. K. Park
- Pohang Univ. of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyungbuk, 790-784, Korea
| | - Y. S. Hwang
- Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 151-742, Korea
| | - Y. S. Na
- Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 151-742, Korea
| | - J. G. Park
- Princeton Plasma Physics Lab., P.O. Box 451 Princetorn, NJ 08543-0451, USA
| | - J. W. Ahn
- Oak Ridge National Lab., 1 Bethal Valley Rd, OakRidge, TN37831, USA
| | - Y. S. Park
- Columbia Univ., James Forrestal Campus (EWA 244), P.O. Box 451, Princeton, NJ 08543, USA
| | - M. Kwon
- National Fusion Research Institute, 113 Gwahangno, Yusung-Gu, Daejeon, 305-333, Korea
| | - J. A. Leuer
- General Atomics, 3550 General Atomics Court, San Diego, CA 92121, USA
| | - N. W. Eidietis
- General Atomics, 3550 General Atomics Court, San Diego, CA 92121, USA
| | - A. W. Hyatt
- General Atomics, 3550 General Atomics Court, San Diego, CA 92121, USA
| | - M. Walker
- General Atomics, 3550 General Atomics Court, San Diego, CA 92121, USA
| | - Y. Gorelov
- General Atomics, 3550 General Atomics Court, San Diego, CA 92121, USA
| | - J. Lohr
- General Atomics, 3550 General Atomics Court, San Diego, CA 92121, USA
| | - D. Mueller
- Princeton Plasma Physics Lab., P.O. Box 451 Princetorn, NJ 08543-0451, USA
| | - L. R. Grisham
- Princeton Plasma Physics Lab., P.O. Box 451 Princetorn, NJ 08543-0451, USA
| | - S. A. Sabbagh
- Columbia Univ., James Forrestal Campus (EWA 244), P.O. Box 451, Princeton, NJ 08543, USA
| | - K. Watanabe
- Japan Atomic Energy Agency, 801-1 Mukoyama, Naka-city, Ibaraki-ken, 311-0193, Japan
| | - T. Inoue
- Japan Atomic Energy Agency, 801-1 Mukoyama, Naka-city, Ibaraki-ken, 311-0193, Japan
| | - K. Sakamoto
- Japan Atomic Energy Agency, 801-1 Mukoyama, Naka-city, Ibaraki-ken, 311-0193, Japan
| | - Y. Oda
- Japan Atomic Energy Agency, 801-1 Mukoyama, Naka-city, Ibaraki-ken, 311-0193, Japan
| | - K. Kajiwara
- Japan Atomic Energy Agency, 801-1 Mukoyama, Naka-city, Ibaraki-ken, 311-0193, Japan
| | - R. Ellis
- Princeton Plasma Physics Lab., P.O. Box 451 Princetorn, NJ 08543-0451, USA
| | - J. Hosea
- Princeton Plasma Physics Lab., P.O. Box 451 Princetorn, NJ 08543-0451, USA
| | - L. Delpech
- CEA, IFRM,13108 Saint-Paul-Lez-Durance, France
| | - T. T. Hoang
- CEA, IFRM,13108 Saint-Paul-Lez-Durance, France
| | - X. Litaudon
- CEA, IFRM,13108 Saint-Paul-Lez-Durance, France
| | - W. Namkung
- Pohang Univ. of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyungbuk, 790-784, Korea
| | - M. H. Cho
- Pohang Univ. of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyungbuk, 790-784, Korea
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10
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Brookman MW, Austin ME, McLean AG, Carlstrom TN, Hyatt AW, Lohr J. Improved cross-calibration of Thomson scattering and electron cyclotron emission with ECH on DIII-D. Rev Sci Instrum 2016; 87:11E517. [PMID: 27910589 DOI: 10.1063/1.4959916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Thomson scattering produces ne profiles from measurement of scattered laser beam intensity. Rayleigh scattering provides a first calibration of the relation ne ∝ ITS, which depends on many factors (e.g., laser alignment and power, optics, and measurement systems). On DIII-D, the ne calibration is adjusted against an absolute ne from the density-driven cutoff of the 48 channel 2nd harmonic X-mode electron cyclotron emission system. This method has been used to calibrate Thomson ne from the edge to near the core (r/a > 0.15). Application of core electron cyclotron heating improves the quality of cutoff and depth of its penetration into the core, and also changes underlying MHD activity, minimizing crashes which confound calibration. Less fueling is needed as "ECH pump-out" generates a plasma ready to take up gas. On removal of gyrotron power, cutoff penetrates into the core as channels fall successively and smoothly into cutoff.
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Affiliation(s)
- M W Brookman
- Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712, USA
| | - M E Austin
- Lawrence Livermore National Lab, Livermore, California 94500, USA
| | - A G McLean
- Lawrence Livermore National Lab, Livermore, California 94500, USA
| | | | - A W Hyatt
- General Atomics, San Diego, California 92122, USA
| | - J Lohr
- General Atomics, San Diego, California 92122, USA
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Piovesan P, Hanson JM, Martin P, Navratil GA, Turco F, Bialek J, Ferraro NM, La Haye RJ, Lanctot MJ, Okabayashi M, Paz-Soldan C, Strait EJ, Turnbull AD, Zanca P, Baruzzo M, Bolzonella T, Hyatt AW, Jackson GL, Marrelli L, Piron L, Shiraki D. Tokamak operation with safety factor q95 < 2 via control of MHD stability. Phys Rev Lett 2014; 113:045003. [PMID: 25105626 DOI: 10.1103/physrevlett.113.045003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Indexed: 06/03/2023]
Abstract
Magnetic feedback control of the resistive-wall mode has enabled the DIII-D tokamak to access stable operation at safety factor q(95) = 1.9 in divertor plasmas for 150 instability growth times. Magnetohydrodynamic stability sets a hard, disruptive limit on the minimum edge safety factor achievable in a tokamak, or on the maximum plasma current at a given toroidal magnetic field. In tokamaks with a divertor, the limit occurs at q(95) = 2, as confirmed in DIII-D. Since the energy confinement time scales linearly with current, this also bounds the performance of a fusion reactor. DIII-D has overcome this limit, opening a whole new high-current regime not accessible before. This result brings significant possible benefits in terms of fusion performance, but it also extends resistive-wall mode physics and its control to conditions never explored before. In present experiments, the q(95) < 2 operation is eventually halted by voltage limits reached in the feedback power supplies, not by intrinsic physics issues. Improvements to power supplies and to control algorithms have the potential to further extend this regime.
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Affiliation(s)
- P Piovesan
- Consorzio RFX, Corso Stati Uniti 4, 35127 Padova, Italy
| | - J M Hanson
- Columbia University, New York, New York 10027, USA
| | - P Martin
- Consorzio RFX, Corso Stati Uniti 4, 35127 Padova, Italy
| | - G A Navratil
- Columbia University, New York, New York 10027, USA
| | - F Turco
- Columbia University, New York, New York 10027, USA
| | - J Bialek
- Columbia University, New York, New York 10027, USA
| | - N M Ferraro
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - R J La Haye
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - M J Lanctot
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - M Okabayashi
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543-0451, USA
| | - C Paz-Soldan
- Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee 37831, USA
| | - E J Strait
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - A D Turnbull
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - P Zanca
- Consorzio RFX, Corso Stati Uniti 4, 35127 Padova, Italy
| | - M Baruzzo
- Consorzio RFX, Corso Stati Uniti 4, 35127 Padova, Italy
| | - T Bolzonella
- Consorzio RFX, Corso Stati Uniti 4, 35127 Padova, Italy
| | - A W Hyatt
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - G L Jackson
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - L Marrelli
- Consorzio RFX, Corso Stati Uniti 4, 35127 Padova, Italy
| | - L Piron
- Consorzio RFX, Corso Stati Uniti 4, 35127 Padova, Italy
| | - D Shiraki
- Columbia University, New York, New York 10027, USA
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Affiliation(s)
- G. L. Jackson
- General Atomics, P.O. Box 85608, San Diego, California 92816-5608
| | - D. A. Humphreys
- General Atomics, P.O. Box 85608, San Diego, California 92816-5608
| | - A. W. Hyatt
- General Atomics, P.O. Box 85608, San Diego, California 92816-5608
| | - J. A. Leuer
- General Atomics, P.O. Box 85608, San Diego, California 92816-5608
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Rudakov DL, Yu JH, Boedo JA, Hollmann EM, Krasheninnikov SI, Moyer RA, Muller SH, Pigarov AY, Rosenberg M, Smirnov RD, West WP, Boivin RL, Bray BD, Brooks NH, Hyatt AW, Wong CPC, Roquemore AL, Skinner CH, Solomon WM, Ratynskaia S, Fenstermacher ME, Groth M, Lasnier CJ, McLean AG, Stangeby PC. Dust measurements in tokamaks (invited). Rev Sci Instrum 2008; 79:10F303. [PMID: 19044616 DOI: 10.1063/1.2969422] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Dust production and accumulation present potential safety and operational issues for the ITER. Dust diagnostics can be divided into two groups: diagnostics of dust on surfaces and diagnostics of dust in plasma. Diagnostics from both groups are employed in contemporary tokamaks; new diagnostics suitable for ITER are also being developed and tested. Dust accumulation in ITER is likely to occur in hidden areas, e.g., between tiles and under divertor baffles. A novel electrostatic dust detector for monitoring dust in these regions has been developed and tested at PPPL. In the DIII-D tokamak dust diagnostics include Mie scattering from Nd:YAG lasers, visible imaging, and spectroscopy. Laser scattering is able to resolve particles between 0.16 and 1.6 microm in diameter; using these data the total dust content in the edge plasmas and trends in the dust production rates within this size range have been established. Individual dust particles are observed by visible imaging using fast framing cameras, detecting dust particles of a few microns in diameter and larger. Dust velocities and trajectories can be determined in two-dimension with a single camera or three-dimension using multiple cameras, but determination of particle size is challenging. In order to calibrate diagnostics and benchmark dust dynamics modeling, precharacterized carbon dust has been injected into the lower divertor of DIII-D. Injected dust is seen by cameras, and spectroscopic diagnostics observe an increase in carbon line (CI, CII, C(2) dimer) and thermal continuum emissions from the injected dust. The latter observation can be used in the design of novel dust survey diagnostics.
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Affiliation(s)
- D L Rudakov
- University of California, San Diego, California 92093, USA
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Whyte DG, Jernigan TC, Humphreys DA, Hyatt AW, Lasnier CJ, Parks PB, Evans TE, Rosenbluth MN, Taylor PL, Kellman AG, Gray DS, Hollmann EM, Combs SK. Mitigation of tokamak disruptions using high-pressure gas injection. Phys Rev Lett 2002; 89:055001. [PMID: 12144446 DOI: 10.1103/physrevlett.89.055001] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2002] [Indexed: 05/23/2023]
Abstract
High-pressure gas-jet injection of neon and argon is shown to be a simple and robust method to mitigate the deleterious effects of disruptions on the DIII-D tokamak. The gas jet penetrates to the central plasma at its sonic velocity. The deposited species dissipates >95% of the plasma by radiation and substantially reduces mechanical stresses on the vessel caused by poloidal halo currents. The gas-jet species-charge distribution can include >50% fraction neutral species which inhibits runaway electrons. The favorable scaling of this technique to burning fusion plasmas is discussed.
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Affiliation(s)
- D G Whyte
- University of California, San Diego, California, USA
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Forest CB, Petty CC, Austin ME, Baity FW, Burrell KH, Chiu SC, Chu MS, deGrassie JS, Gohil P, Hyatt AW, Ikezi H, Lazarus EA, Murakami M, Pinsker RI, Porkolab M, Prater R, Rice BW, Staebler GM, Strait EJ, Taylor TS, Whyte DG. Energy Transport in Tokamak Plasmas with Central Current Density Control Using Fast Waves. Phys Rev Lett 1996; 77:3141-3144. [PMID: 10062144 DOI: 10.1103/physrevlett.77.3141] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Lazarus EA, Navratil GA, Greenfield CM, Strait EJ, Austin ME, Burrell KH, Casper TA, Baker DR, DeBoo JC, Doyle EJ, Durst R, Ferron JR, Forest CB, Gohil P, Groebner RJ, Heidbrink WW, Hong R, Houlberg WA, Howald AW, Hsieh C, Hyatt AW, Jackson GL, Kim J, Lao LL, Lasnier CJ, Leonard AW, Lohr J, Maingi R, Miller RL, Murakami M, Osborne TH, Perkins LJ, Petty CC, Rettig CL, Rhodes TL, Rice BW, Sabbagh SA, Schissel DP, Scoville JT, Snider RT, Staebler GM, Stallard BW, Stambaugh RD, Stockdale RE, Taylor PL, Thomas DM, Turnbull AD, Wade MR, Wood R, Whyte D. Higher Fusion Power Gain with Current and Pressure Profile Control in Strongly Shaped DIII-D Tokamak Plasmas. Phys Rev Lett 1996; 77:2714-2717. [PMID: 10062027 DOI: 10.1103/physrevlett.77.2714] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Eggleston DL, Driscoll CF, Beck BR, Hyatt AW, Malmberg JH. Parallel energy analyzer for pure electron plasma devices. ACTA ACUST UNITED AC 1992. [DOI: 10.1063/1.860399] [Citation(s) in RCA: 87] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Malmberg JH, Driscoll CF, Beck B, Eggleston DL, Fajans J, Fine K, Huang XP, Hyatt AW. Experiments with pure electron plasmas. ACTA ACUST UNITED AC 1988. [DOI: 10.1063/1.37613] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Hyatt AW, Driscoll CF, Malmberg JH. Measurement of the anisotropic temperature relaxation rate in a pure electron plasma. Phys Rev Lett 1987; 59:2975-2978. [PMID: 10035701 DOI: 10.1103/physrevlett.59.2975] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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