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Kim SK, Shousha R, Yang SM, Hu Q, Hahn SH, Jalalvand A, Park JK, Logan NC, Nelson AO, Na YS, Nazikian R, Wilcox R, Hong R, Rhodes T, Paz-Soldan C, Jeon YM, Kim MW, Ko WH, Lee JH, Battey A, Yu G, Bortolon A, Snipes J, Kolemen E. Highest fusion performance without harmful edge energy bursts in tokamak. Nat Commun 2024; 15:3990. [PMID: 38734685 PMCID: PMC11088687 DOI: 10.1038/s41467-024-48415-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 04/29/2024] [Indexed: 05/13/2024] Open
Abstract
The path of tokamak fusion and International thermonuclear experimental reactor (ITER) is maintaining high-performance plasma to produce sufficient fusion power. This effort is hindered by the transient energy burst arising from the instabilities at the boundary of plasmas. Conventional 3D magnetic perturbations used to suppress these instabilities often degrade fusion performance and increase the risk of other instabilities. This study presents an innovative 3D field optimization approach that leverages machine learning and real-time adaptability to overcome these challenges. Implemented in the DIII-D and KSTAR tokamaks, this method has consistently achieved reactor-relevant core confinement and the highest fusion performance without triggering damaging bursts. This is enabled by advances in the physics understanding of self-organized transport in the plasma edge and machine learning techniques to optimize the 3D field spectrum. The success of automated, real-time adaptive control of such complex systems paves the way for maximizing fusion efficiency in ITER and beyond while minimizing damage to device components.
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Affiliation(s)
- S K Kim
- Princeton Plasma Physics Laboratory, Princeton, NJ, USA
| | - R Shousha
- Princeton Plasma Physics Laboratory, Princeton, NJ, USA
| | - S M Yang
- Princeton Plasma Physics Laboratory, Princeton, NJ, USA
| | - Q Hu
- Princeton Plasma Physics Laboratory, Princeton, NJ, USA
| | - S H Hahn
- Korea Institute of Fusion Energy, Daejeon, South Korea
| | | | - J-K Park
- Seoul National University, Seoul, South Korea
| | - N C Logan
- Columbia University, New York, NY, USA
| | | | - Y-S Na
- Seoul National University, Seoul, South Korea
| | | | - R Wilcox
- Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - R Hong
- University of California Los Angeles, Los Angeles, CA, USA
| | - T Rhodes
- University of California Los Angeles, Los Angeles, CA, USA
| | | | - Y M Jeon
- Korea Institute of Fusion Energy, Daejeon, South Korea
| | - M W Kim
- Korea Institute of Fusion Energy, Daejeon, South Korea
| | - W H Ko
- Korea Institute of Fusion Energy, Daejeon, South Korea
| | - J H Lee
- Korea Institute of Fusion Energy, Daejeon, South Korea
| | - A Battey
- Columbia University, New York, NY, USA
| | - G Yu
- University of California Davis, Davis, CA, USA
| | - A Bortolon
- Princeton Plasma Physics Laboratory, Princeton, NJ, USA
| | - J Snipes
- Princeton Plasma Physics Laboratory, Princeton, NJ, USA
| | - E Kolemen
- Princeton Plasma Physics Laboratory, Princeton, NJ, USA.
- Princeton University, Princeton, NJ, USA.
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Chouchene S, Brochard F, Lemoine N, Cavalier J, Desecures M, Weinzettl V. Mutual interactions between plasma filaments in a tokamak evidenced by fast imaging and machine learning. Phys Rev E 2024; 109:045201. [PMID: 38755804 DOI: 10.1103/physreve.109.045201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 02/26/2024] [Indexed: 05/18/2024]
Abstract
Magnetically confined fusion plasmas are subject to various instabilities that cause turbulent transport of particles and heat across the magnetic field. In the edge plasma region, this transport takes the form of long filaments stretched along the magnetic field lines. Understanding the dynamics of these filaments, referred to as blobs, is crucial for predicting and controlling their impact on reactor performance. To achieve this, highly resolved passive fast camera measurements have been conducted on the COMPASS tokamak. These measurements are analyzed using both conventional tracking methods and a custom-developed machine-learning approach designed to characterize more particularly the mutual interactions between filaments. Our findings demonstrate that up to 18% of blobs exhibit mutual interactions in the investigated area close to the separatrix, at the border between confined and nonconfined plasma. Notably, we present direct observations and radial dependence of blob coalescence and splitting, rapid reversals in the propagation direction of the blob, as well as their dependence on the radial position. The comparison between observations realized with passive and gas puff imaging does not evidence any significant bias due to the use of the latter technique.
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Affiliation(s)
- Sarah Chouchene
- Université de Lorraine, Institut Jean Lamour, CNRS, Nancy 54000, France
- APREX Solutions, Pulligny 54160, France
| | - Frédéric Brochard
- Université de Lorraine, Institut Jean Lamour, CNRS, Nancy 54000, France
| | - Nicolas Lemoine
- Université de Lorraine, Institut Jean Lamour, CNRS, Nancy 54000, France
| | - Jordan Cavalier
- Institute of Plasma Physics of the CAS, Prague 8, 18200, Czech Republic
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Viezzer E, Austin M, Bernert M, Burrell K, Cano-Megias P, Chen X, Cruz-Zabala D, Coda S, Faitsch M, Fevrier O, Gil L, Giroud C, Happel T, Harrer G, Hubbard A, Hughes J, Kallenbach A, Labit B, Merle A, Meyer H, Paz-Soldan C, Oyola P, Sauter O, Siccinio M, Silvagni D, Solano E. Prospects of core–edge integrated no-ELM and small-ELM scenarios for future fusion devices. NUCLEAR MATERIALS AND ENERGY 2022. [DOI: 10.1016/j.nme.2022.101308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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