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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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2
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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; 629:555-560. [PMID: 38658758 PMCID: PMC11096097 DOI: 10.1038/s41586-024-07313-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [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
- University of California San Diego, La Jolla, CA, USA
- 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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3
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Lampert M, Diallo A, Zweben SJ. Novel angular velocity estimation technique for plasma filaments. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2023; 94:013505. [PMID: 36725563 DOI: 10.1063/5.0128818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 12/12/2022] [Indexed: 06/18/2023]
Abstract
Magnetic field aligned filaments such as blobs and edge localized mode filaments carry significant amounts of heat and particles to the plasma facing components and they decrease their lifetime. The dynamics of these filaments determine at least a part of the heat and particle loads. These dynamics can be characterized by their translation and rotation. In this paper, we present an analysis method novel for fusion plasmas, which can estimate the angular velocity of the filaments on frame-by-frame time resolution. After pre-processing, the frames are two-dimensional (2D) Fourier-transformed, then the resulting 2D Fourier magnitude spectra are transformed to log-polar coordinates, and finally the 2D cross-correlation coefficient function (CCCF) is calculated between the consecutive frames. The displacement of the CCCF's peak along the angular coordinate estimates the angle of rotation of the most intense structure in the frame. The proposed angular velocity estimation method is tested and validated for its accuracy and robustness by applying it to rotating Gaussian-structures. The method is also applied to gas-puff imaging measurements of filaments in National Spherical Torus Experiment plasmas.
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Affiliation(s)
- M Lampert
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540, USA
| | - A Diallo
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540, USA
| | - S J Zweben
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540, USA
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4
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Redl A, Eich T, Vianello N, David P. Energy load on first wall components in high density, small ELM regimes in ASDEX Upgrade. NUCLEAR MATERIALS AND ENERGY 2022. [DOI: 10.1016/j.nme.2022.101319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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5
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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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6
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Harrer GF, Faitsch M, Radovanovic L, Wolfrum E, Albert C, Cathey A, Cavedon M, Dunne M, Eich T, Fischer R, Griener M, Hoelzl M, Labit B, Meyer H, Aumayr F. Quasicontinuous Exhaust Scenario for a Fusion Reactor: The Renaissance of Small Edge Localized Modes. PHYSICAL REVIEW LETTERS 2022; 129:165001. [PMID: 36306746 DOI: 10.1103/physrevlett.129.165001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 07/08/2022] [Accepted: 08/08/2022] [Indexed: 06/16/2023]
Abstract
Tokamak operational regimes with small edge localized modes (ELMs) could be a solution to the problem of large transient heat loads in fusion reactors. A ballooning mode near the last closed flux surface governed by the pressure gradient and the magnetic shear there has been proposed for small ELMs. In this Letter, we experimentally investigate several stabilizing effects near the last closed flux surface and present linear ideal simulations that indeed develop ballooninglike fluctuations there and connect them with nonlinear resistive simulations. The dimensionless parameters of the small ELM regime in the region of interest are very similar to those in a reactor, making this regime the ideal exhaust scenario for a future device.
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Affiliation(s)
- G F Harrer
- Institute of Applied Physics, TU Wien, Fusion@ÖAW, Vienna, Austria
- Max Planck Institute for Plasma Physics, Garching, Germany
| | - M Faitsch
- Max Planck Institute for Plasma Physics, Garching, Germany
| | - L Radovanovic
- Institute of Applied Physics, TU Wien, Fusion@ÖAW, Vienna, Austria
- Max Planck Institute for Plasma Physics, Garching, Germany
| | - E Wolfrum
- Max Planck Institute for Plasma Physics, Garching, Germany
| | - C Albert
- Institute of Theoretical and Computational Physics, TU Graz, Graz, Austria
| | - A Cathey
- Max Planck Institute for Plasma Physics, Garching, Germany
| | - M Cavedon
- Dipartimento di Fisica "G. Occhialini," Università di Milano-Bicocca, Milano, Italy
| | - M Dunne
- Max Planck Institute for Plasma Physics, Garching, Germany
| | - T Eich
- Max Planck Institute for Plasma Physics, Garching, Germany
| | - R Fischer
- Max Planck Institute for Plasma Physics, Garching, Germany
| | - M Griener
- Max Planck Institute for Plasma Physics, Garching, Germany
| | - M Hoelzl
- Max Planck Institute for Plasma Physics, Garching, Germany
| | - B Labit
- École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
| | - H Meyer
- CCFE, Culham Science Centre, Abingdon, Oxon, United Kingdom
| | - F Aumayr
- Institute of Applied Physics, TU Wien, Fusion@ÖAW, Vienna, Austria
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7
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Looby T, Reinke M, Wingen A, Menard J, Gerhardt S, Gray T, Donovan D, Unterberg E, Klabacha J, Messineo M. A Software Package for Plasma-Facing Component Analysis and Design: The Heat Flux Engineering Analysis Toolkit (HEAT). FUSION SCIENCE AND TECHNOLOGY 2022. [DOI: 10.1080/15361055.2021.1951532] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- T. Looby
- University of Tennessee–Knoxville, Nuclear Engineering Department, 1412 Circle Drive, Knoxville, Tennessee 37916
| | - M. Reinke
- Commonwealth Fusion Systems, 148 Sidney Street, Cambridge, Massachusetts 02139
- Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37830
| | - A. Wingen
- Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37830
| | - J. Menard
- Princeton Plasma Physics Laboratory, 100 Stellarator Road, Princeton, New Jersey 08540
| | - S. Gerhardt
- Princeton Plasma Physics Laboratory, 100 Stellarator Road, Princeton, New Jersey 08540
| | - T. Gray
- Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37830
| | - D. Donovan
- University of Tennessee–Knoxville, Nuclear Engineering Department, 1412 Circle Drive, Knoxville, Tennessee 37916
| | - E. Unterberg
- Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37830
| | - J. Klabacha
- Princeton Plasma Physics Laboratory, 100 Stellarator Road, Princeton, New Jersey 08540
| | - M. Messineo
- Princeton Plasma Physics Laboratory, 100 Stellarator Road, Princeton, New Jersey 08540
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8
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Observation of surface deformation of tungsten exposed to single pulsed high heat flux and magnetic field for divertor design. FUSION ENGINEERING AND DESIGN 2021. [DOI: 10.1016/j.fusengdes.2021.112547] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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9
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Lampert M, Diallo A, Zweben SJ. Novel 2D velocity estimation method for large transient events in plasmas. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:083508. [PMID: 34470435 DOI: 10.1063/5.0058216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 07/16/2021] [Indexed: 06/13/2023]
Abstract
Dynamics of fast transient events are challenging to be analyzed with high time resolution. Such events can occur in fusion plasmas such as the filaments during edge-localized modes (ELMs). In this paper, we present a robust method-the spatial displacement estimation-for estimating the displacements of structures with fast dynamics from high spatial and time resolution imaging diagnostics [e.g., gas-puff imaging (GPI)] with sampling time temporal resolution. First, a background suppression method is shown, which suppresses the slowly time-evolving and spatially non-uniform background in the signal. In the second step, a two-dimensional polynomial trend subtraction method is presented to tackle the remaining polynomial order trend in the signal. After performing these pre-processing steps, the spatial displacement of the propagating structure is estimated from the two-dimensional spatial cross-correlation coefficient function calculated between consecutive frames. The method is tested for its robustness and accuracy by simulated Gaussian events and spatially displaced random noise. An example application of the method is presented on propagating ELM filaments measured by the GPI system on the National Spherical Torus Experiment spherical tokamak.
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Affiliation(s)
- M Lampert
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540, USA
| | - A Diallo
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540, USA
| | - S J Zweben
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540, USA
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10
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Vasileska I, Bonnin X, Kos L. Kinetic-fluid coupling simulations of ITER Type I ELM. FUSION ENGINEERING AND DESIGN 2021. [DOI: 10.1016/j.fusengdes.2021.112407] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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11
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Impact of ELM mitigation on the ITER monoblock thermal behavior and the tungsten recrystallization depth. NUCLEAR MATERIALS AND ENERGY 2021. [DOI: 10.1016/j.nme.2021.101009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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12
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Gunn J, Bucalossi J, Corre Y, Diez M, Delmas E, Fedorczak N, Grosjean A, Firdaouss M, Gaspar J, Loarer T, Missirlian M, Moreau P, Nardon E, Reux C, Richou M, Tsitrone E. Thermal loads in gaps between ITER divertor monoblocks: First lessons learnt from WEST. NUCLEAR MATERIALS AND ENERGY 2021. [DOI: 10.1016/j.nme.2021.100920] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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13
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Maviglia F, Siccinio M, Bachmann C, Biel W, Cavedon M, Fable E, Federici G, Firdaouss M, Gerardin J, Hauer V, Ivanova-Stanik I, Janky F, Kembleton R, Militello F, Subba F, Varoutis S, Vorpahl C. Impact of plasma-wall interaction and exhaust on the EU-DEMO design. NUCLEAR MATERIALS AND ENERGY 2021. [DOI: 10.1016/j.nme.2020.100897] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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14
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In-situ measurement of surface modifications of tungsten exposed to pulsed high heat flux for divertor design in tokamak-type fusion nuclear reactors. FUSION ENGINEERING AND DESIGN 2020. [DOI: 10.1016/j.fusengdes.2020.112042] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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15
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Modeling of COMPASS tokamak divertor liquid metal experiments. NUCLEAR MATERIALS AND ENERGY 2020. [DOI: 10.1016/j.nme.2020.100860] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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16
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Dejarnac R, Horacek J, Hron M, Jerab M, Adamek J, Atikukke S, Barton P, Cavalier J, Cecrdle J, Dimitrova M, Gauthier E, Iafrati M, Imrisek M, Marin Roldan A, Mazzitelli G, Naydenkova D, Prishvitcyn A, Tomes M, Tskhakaya D, Van Oost G, Varju J, Veis P, Vertkov A, Vondracek P, Weinzettl V. Overview of power exhaust experiments in the COMPASS divertor with liquid metals. NUCLEAR MATERIALS AND ENERGY 2020. [DOI: 10.1016/j.nme.2020.100801] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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17
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Origin and nature of the emissive sheath surrounding hot tungsten tokamak surfaces. NUCLEAR MATERIALS AND ENERGY 2020. [DOI: 10.1016/j.nme.2020.100818] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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18
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19
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Igitkhanov Y, Bazylev B, Boccaccini L. Vapor Shielding Effect on DEMO Divertor. FUSION SCIENCE AND TECHNOLOGY 2019. [DOI: 10.1080/15361055.2019.1610291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
| | - Boris Bazylev
- Karlsruhe Institute of Technology, Karlsruhe, Germany
- South Ural State University, Lenin Prospect 76, 454080 Chelyabinsk, Russian Federation
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20
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Pitts R, Bonnin X, Escourbiac F, Frerichs H, Gunn J, Hirai T, Kukushkin A, Kaveeva E, Miller M, Moulton D, Rozhansky V, Senichenkov I, Sytova E, Schmitz O, Stangeby P, De Temmerman G, Veselova I, Wiesen S. Physics basis for the first ITER tungsten divertor. NUCLEAR MATERIALS AND ENERGY 2019. [DOI: 10.1016/j.nme.2019.100696] [Citation(s) in RCA: 113] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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21
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Supplemental ELM control in ITER through beryllium granule injection. NUCLEAR MATERIALS AND ENERGY 2019. [DOI: 10.1016/j.nme.2019.02.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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22
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De Temmerman G, Doerner R, Pitts R. A growth/annealing equilibrium model for helium-induced nanostructure with application to ITER. NUCLEAR MATERIALS AND ENERGY 2019. [DOI: 10.1016/j.nme.2019.01.034] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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23
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Abrams T, Unterberg E, McLean A, Rudakov D, Wampler W, Knolker M, Lasnier C, Leonard A, Stangeby P, Thomas D, Wang H. Experimental validation of a model for particle recycling and tungsten erosion during ELMs in the DIII-D divertor. NUCLEAR MATERIALS AND ENERGY 2018. [DOI: 10.1016/j.nme.2018.10.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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