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Murari A, Rossi R, Craciunescu T, Vega J, Gelfusa M. A control oriented strategy of disruption prediction to avoid the configuration collapse of tokamak reactors. Nat Commun 2024; 15:2424. [PMID: 38499564 PMCID: PMC10948913 DOI: 10.1038/s41467-024-46242-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 02/20/2024] [Indexed: 03/20/2024] Open
Abstract
The objective of thermonuclear fusion consists of producing electricity from the coalescence of light nuclei in high temperature plasmas. The most promising route to fusion envisages the confinement of such plasmas with magnetic fields, whose most studied configuration is the tokamak. Disruptions are catastrophic collapses affecting all tokamak devices and one of the main potential showstoppers on the route to a commercial reactor. In this work we report how, deploying innovative analysis methods on thousands of JET experiments covering the isotopic compositions from hydrogen to full tritium and including the major D-T campaign, the nature of the various forms of collapse is investigated in all phases of the discharges. An original approach to proximity detection has been developed, which allows determining both the probability of and the time interval remaining before an incoming disruption, with adaptive, from scratch, real time compatible techniques. The results indicate that physics based prediction and control tools can be developed, to deploy realistic strategies of disruption avoidance and prevention, meeting the requirements of the next generation of devices.
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Affiliation(s)
- Andrea Murari
- Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA), Corso Stati Uniti 4, Padova, Italy
- Istituto per la Scienza e la Tecnologia dei Plasmi, CNR, Padova, Italy
| | - Riccardo Rossi
- University of Rome "Tor Vergata", via del Politecnico 1, Roma, Italy
| | - Teddy Craciunescu
- National Institute for Laser, Plasma and Radiation Physics, Magurele-Bucharest, Romania
| | - Jesús Vega
- Laboratorio Nacional de Fusión, CIEMAT. Av. Complutense 40, Madrid, Spain
| | - Michela Gelfusa
- University of Rome "Tor Vergata", via del Politecnico 1, Roma, Italy.
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Pastore F, Felici F, Bosman T, Galperti C, Sauter O, Vincent B, Vu N. Model-based electron density estimation using multiple diagnostics on TCV. FUSION ENGINEERING AND DESIGN 2023. [DOI: 10.1016/j.fusengdes.2023.113615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
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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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Parameter study of L–H transition for plasma operation scenario development in JA DEMO. FUSION ENGINEERING AND DESIGN 2023. [DOI: 10.1016/j.fusengdes.2022.113369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Grenfell G, Manz P, Conway G, Eich T, Adamek J, Brida D, Komm M, Nishizawa T, Griener M, Tal B, Stroth U. Turbulence in the near scrape-off layer towards the L-mode density limit in ASDEX-Upgrade. NUCLEAR MATERIALS AND ENERGY 2022. [DOI: 10.1016/j.nme.2022.101277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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