Article
Physics, Fluids & Plasmas
G. Ciraolo, S. Di Genova, H. Yang, A. Gallo, N. Fedorczak, H. Bufferand, J. P. Gunn, P. Tamain, R. Guirlet, C. Guillemaut, C. Desgranges, C. Bourdelle, E. Tsitrone, J. Bucalossi, M. Scotto D'Abusco, E. Serre, Y. Marandet, M. Raghunathan, A. Sepetys, J. Romazanov, A. Kirschner, S. Brezinsek
Summary: The study investigates the transport and poloidal distribution of light impurities in WEST experiments, along with strategies to reduce core contamination due to tungsten penetration using numerical modeling.
Article
Multidisciplinary Sciences
Woonghee Han, Randall A. Pietersen, Rafael Villamor-Lora, Matthew Beveridge, Nicola Offeddu, Theodore Golfinopoulos, Christian Theiler, James L. Terry, Earl S. Marmar, Iddo Drori
Summary: This study applies motion tracking to identify and track turbulent filaments in fusion plasmas using high-frequency videos obtained from Gas Puff Imaging diagnostics. The accuracy of the techniques is confirmed through comparisons of different methods on synthetic and real-world data, and a publicly available dataset and benchmark are provided to facilitate plasma research.
SCIENTIFIC REPORTS
(2022)
Article
Physics, Fluids & Plasmas
T. M. Wilks, L. A. Morton, D. M. Kriete, M. Knolker, P. B. Snyder, K. Barada, C. Paz-Soldan, T. Rhodes, K. H. Burrell, X. Chen, J. W. Hughes
Summary: Experiments on the DIII-D tokamak have pushed the operational limits of wide pedestal quiescent H-mode plasmas towards increased ITER relevance by demonstrating well-matched plasma shape and zero injected torque. Wide pedestal QH-modes, with enhanced edge transport generated by turbulence or a limit cycle oscillation, are seen as a promising regime for future power producing devices.
Article
Physics, Fluids & Plasmas
Hanhui Li, Youwen Sun, Lu Wang, Kaiyang He, Ker-Chung Shaing
Summary: This study proposes a new mechanism based on neoclassical toroidal plasma viscosity induced by symmetry breaking to explain spontaneous plasma rotation and its reversals in tokamaks. The mechanism, which involves considering a small non-axisymmetric displacement in the plasma center, replicates the observed phenomena well, including the nonlinear hysteresis process of rotation reversals. This mechanism may potentially lead to more cost-effective operation of future tokamak fusion reactors.
Article
Physics, Fluids & Plasmas
R. D. Smirnov, S. I. Krasheninnikov
Summary: The paper presents computer simulation studies on burst injection of carbon and tungsten dust particles in DIII-D-like edge plasmas. The injection results in a large transient influx of low- and high-Z impurities associated with dust ablation in the plasmas. The dust transport and the effects of ablated impurities on edge plasma dynamics are investigated in a modern mid-size tokamak geometry under both low- and high-power plasma discharge conditions.
PHYSICS OF PLASMAS
(2023)
Article
Computer Science, Interdisciplinary Applications
Ben Zhu, Haruki Seto, Xue-qiao Xu, Masatoshi Yagi
Summary: The upgraded Landau fluid six-field turbulence model within the BOUT++ framework enhances the capability to study a wider range of tokamak edge phenomena, crucial for building a fully self-consistent edge turbulence model.
COMPUTER PHYSICS COMMUNICATIONS
(2021)
Article
Physics, Fluids & Plasmas
P. Macha, J. Adamek, J. Seidl, J. Stockel, V. Svoboda, G. Van Oost, L. Lobko, J. Krbec
Summary: We report the first experimental observation of a spontaneously formed transport barrier in a circular configuration tokamak with helium plasmas. We clearly observe distinct characteristics of the transport barrier, including a steep gradient of electron temperature and an enhanced radial electric field. This observation may bring new possibilities for fusion-relevant study of edge plasma parameters and transport in helium plasmas even on small tokamaks.
Article
Nuclear Science & Technology
B. J. Ding, C. B. Wu, Y. C. Li, M. H. Li, Y. F. Wang, B. Zhang, G. H. Yan, H. Q. Liu, L. Wang, M. Wang, R. Ding, H. C. Hu, H. Lian, R. Cesario, A. A. Tuccillo, S. G. Baek, P. Bonoli, A. Ekedahl, J. F. Shan, F. K. Liu, J. P. Qian, X. Z. Gong, B. N. Wan
Summary: By studying the effect of edge plasma density on hot spot and current drive in EAST, it was found that the hot spot is mainly related to edge density and LH power, while stronger parametric instability behavior leads to a decrease in current drive capability.
NUCLEAR MATERIALS AND ENERGY
(2021)
Article
Physics, Fluids & Plasmas
M. Willensdorfer, U. Plank, D. Brida, M. Cavedon, G. D. Conway, D. A. Ryan, W. Suttrop, R. Buchholz, M. Dunne, R. Fischer, M. Griener, J. Hobirk, S. Kasilov, A. Kirk, R. M. McDermott, T. Puetterich, G. Tardini, Q. Yu
Summary: Experiments at ASDEX Upgrade have shown that the alignment of external magnetic perturbations with toroidal mode symmetry can significantly affect the power threshold for the transition from L- to H-mode. The increase in power threshold is observed when the external magnetic field is aligne d to maximize the plasma response at the edge, reaching up to approximately 80%. The increase in power threshold is dependent on the magnitude of the radial magnetic field perturbation and its alignment with the plasma response.
PHYSICS OF PLASMAS
(2022)
Article
Physics, Multidisciplinary
Chenchen Qin, Maolin Mou, Shaoyong Chen, Changjian Tang
Summary: The study shows that plasma shaping can significantly affect the instability of peeling-ballooning mode, with elongation impacting growth rates and triangularity having an opposing effect on growth rates.
Article
Computer Science, Interdisciplinary Applications
Usman Riaz, E. Seegyoung Seol, Robert Hager, Mark S. Shephard
Summary: The accurate representation and effective discretization of a problem domain into a mesh are crucial for achieving high-quality simulation results and computational efficiency. This work presents recent developments in extending an automated tokamak modeling and meshing infrastructure to better support the near flux field following meshing requirements of the XGC Gyro-kinetic Code.
COMPUTER PHYSICS COMMUNICATIONS
(2024)
Article
Nuclear Science & Technology
E. Laribi, E. Serre, P. Tamain, H. Yang
Summary: This study investigates the impact of triangularity on edge plasma transport and turbulence through full 3D turbulence simulations. Results show that negative triangularity leads to reductions in density and electron temperature decay lengths, and turbulence remains ballooned with enhanced fluctuations at low field side. However, the impact of triangularity on turbulent transport remains inconclusive based on the preliminary study.
NUCLEAR MATERIALS AND ENERGY
(2021)
Article
Instruments & Instrumentation
A. M. Rosenthal, J. W. Hughes, A. Bortolon, F. M. Laggner, T. M. Wilks, R. Vieira, R. Leccacorvi, E. Marmar, A. Nagy, C. Freeman, D. Mauzey
Summary: An absolutely calibrated pinhole camera system was installed on the DIII-D tokamak to measure edge Lyman-alpha emission from hydrogen isotopes, providing spatially resolved brightness measurements for studying divertor neutral leakage, main chamber fueling, and radial particle transport.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2021)
Article
Physics, Fluids & Plasmas
M. Ono, N. Bertelli, V Shevchenko, H. Idei, K. Hanada
Summary: An accessibility enhanced efficient fundamental X-mode electron cyclotron heating (ECH) current start-up regime, with over 100 times higher current drive efficiency compared to conventional methods, has been identified for a reactor-like toroidal magnetic field range. The high current drive efficiency is achieved due to the strong cyclotron interaction with unidirectional passing electrons constrained by wave accessibility conditions.
Review
Physics, Fluids & Plasmas
C. Paz-Soldan
Summary: The study compared different no-ELM plasma states in the DIII-D plasma database, finding that QH, RMP, and Neg-D states have advantages in power tolerance, while the absolute performance linearly related to IaB is highest in QH and RMP states.
PLASMA PHYSICS AND CONTROLLED FUSION
(2021)
Article
Physics, Fluids & Plasmas
W. Guttenfelder, D. J. Battaglia, E. Belova, N. Bertelli, M. D. Boyer, C. S. Chang, A. Diallo, V. N. Duarte, F. Ebrahimi, E. D. Emdee, N. Ferraro, E. Fredrickson, N. N. Gorelenkov, W. Heidbrink, Z. Ilhan, S. M. Kaye, E-H Kim, A. Kleiner, F. Laggner, M. Lampert, J. B. Lestz, C. Liu, D. Liu, T. Looby, N. Mandell, R. Maingi, J. R. Myra, S. Munaretto, M. Podesta, T. Rafiq, R. Raman, M. Reinke, Y. Ren, J. Ruiz Ruiz, F. Scotti, S. Shiraiwa, V Soukhanovskii, P. Vail, Z. R. Wang, W. Wehner, A. E. White, R. B. White, B. J. Q. Woods, J. Yang, S. J. Zweben, S. Banerjee, R. Barchfeld, R. E. Bell, J. W. Berkery, A. Bhattacharjee, A. Bierwage, G. P. Canal, X. Chen, C. Clauser, N. Crocker, C. Domier, T. Evans, M. Francisquez, K. Gan, S. Gerhardt, R. J. Goldston, T. Gray, A. Hakim, G. Hammett, S. Jardin, R. Kaita, B. Koel, E. Kolemen, S-H Ku, S. Kubota, B. P. LeBlanc, F. Levinton, J. D. Lore, N. Luhmann, R. Lunsford, R. Maqueda, J. E. Menard, J. H. Nichols, M. Ono, J-K Park, F. Poli, T. Rhodes, J. Riquezes, D. Russell, S. A. Sabbagh, E. Schuster, D. R. Smith, D. Stotler, B. Stratton, K. Tritz, W. Wang, B. Wirth
Summary: The mission of NSTX-U is to advance the physics and technical solutions for next-step steady-state tokamak fusion devices. It aims to develop a deeper understanding of high-performance non-inductive plasmas and solve challenges related to plasma exhaust and thermal transport.
Article
Physics, Fluids & Plasmas
R. Kube, R. M. Churchill, C. S. Chang, J. Choi, R. Wang, S. Klasky, L. Stephey, E. Dart, M. J. Choi
Summary: In this article, the Delta framework is introduced for near real-time streaming analysis of big and fast fusion data. The framework allows computationally expensive data analysis tasks to be performed in between plasma pulses by streaming measurement data to a high-performance compute center. The Delta framework uses modern database systems and container orchestration services to provide web-based real-time data visualization and integrates machine learning models for enhanced data analysis.
PLASMA PHYSICS AND CONTROLLED FUSION
(2022)
Article
Physics, Fluids & Plasmas
Hongxuan Zhu, T. Stoltzfus-Dueck, R. Hager, S. Ku, C. S. Chang
Summary: This study quantitatively measures the loss-orbit current in the edge pedestal using the ion-orbit-flux diagnostic. The results show that the effect of orbit loss on the radial electric field E (r) in the plasma is mild.
Article
Physics, Fluids & Plasmas
P. Trivedi, J. Dominski, C. S. Chang, S. Ku
Summary: This study investigates the differences between core coupled simplified Delta-f and total-f gyrokinetic models and performs large-scale gyrokinetic 3D turbulence simulations. The results show that the radial electric field and its drive must be consistently considered when coupling different models together.
PHYSICS OF PLASMAS
(2022)
Article
Physics, Fluids & Plasmas
T. Moritaka, H. Sugama, M. D. J. Cole, R. Hager, S. Ku, C. S. Chang, S. Ishiguro
Summary: This study examines the isotope effects under a radial electric field in a helical magnetic field configuration. The results show that in single-ion-species plasmas, the heat flux exhibits a mass number dependency consistent with gyro-Bohm scaling. However, in multi-ion-species plasmas with a global radial electric field or a heavy hydrogen component, the heat flux shows favorable mass number dependencies that violate gyro-Bohm scaling.
Article
Physics, Fluids & Plasmas
A. Y. Sharma, M. D. J. Cole, T. Goerler, Y. Chen, D. R. Hatch, W. Guttenfelder, R. Hager, B. J. Sturdevant, S. Ku, A. Mishchenko, C. S. Chang
Summary: The effects of plasma shaping on the global, ion-scale electromagnetic modes are studied, and it is found that the growth rates of these modes are significantly reduced in high elongation and high triangularity geometries.
PHYSICS OF PLASMAS
(2022)
Article
Physics, Fluids & Plasmas
Robert Hager, S. Ku, A. Y. Sharma, C. S. Chang, R. M. Churchill, A. Scheinberg
Summary: This study generalizes the XGC core plasma simulation algorithm to a total-f electromagnetic algorithm that can include boundary plasma, turbulence, and neoclassical physics. An electromagnetic demonstration simulation in a DIII-D-like H-mode boundary plasma confirms the necessity of electromagnetic simulation for a better understanding of electron particle and heat transport.
PHYSICS OF PLASMAS
(2022)
Article
Physics, Fluids & Plasmas
Hongxuan Zhu, T. Stoltzfus-Dueck, R. Hager, S. Ku, C. S. Chang
Summary: Ion orbit loss can generate a negative radial electric field and co-current toroidal rotation in tokamak edge plasmas. Collisional ion orbit loss can contribute to the formation of a quasisteady negative electric field in the plasma edge and shift the edge toroidal rotation in the co-current direction on the collisional time scale.
Editorial Material
Nanoscience & Nanotechnology
Choongseok Chang, Volker L. Deringer, Kalpana S. Katti, Veronique Van Speybroeck, Christopher M. Wolverton
Summary: Exascale computers, capable of performing 10(18) floating point operations per second, have started to become operational in 2022. The United States has launched Frontier as the first public exascale supercomputer, and Aurora is set to open soon. In China, OceanLight and Tianhe-3 are already operational, while Europe is getting ready to launch JUPITER in 2023. Supercomputers present unprecedented opportunities for modeling complex materials.
NATURE REVIEWS MATERIALS
(2023)
Review
Physics, Fluids & Plasmas
Rushil Anirudh, Rick Archibald, M. Salman Asif, Markus M. Becker, Sadruddin Benkadda, Peer-Timo Bremer, Rick H. S. Bude, C. S. Chang, Lei Chen, R. M. Churchill, Jonathan Citrin, Jim A. Gaffney, Ana Gainaru, Walter Gekelman, Tom Gibbs, Satoshi Hamaguchi, Christian Hill, Kelli Humbird, Soeren Jalas, Satoru Kawaguchi, Gon-Ho Kim, Manuel Kirchen, Scott Klasky, John L. Kline, Karl Krushelnick, Bogdan Kustowski, Giovanni Lapenta, Wenting Li, Tammy Ma, Nigel J. Mason, Ali Mesbah, Craig Michoski, Todd Munson, Izumi Murakami, Habib N. Najm, K. Erik J. Olofsson, Seolhye Park, J. Luc Peterson, Michael Probst, David Pugmire, Brian Sammuli, Kapil Sawlani, Alexander Scheinker, David P. Schissel, Rob J. Shalloo, Jun Shinagawa, Jaegu Seong, Brian K. Spears, Jonathan Tennyson, Jayaraman Thiagarajan, Catalin M. Ticos, Jan Trieschmann, Jan van Dijk, Brian Van Essen, Peter Ventzek, Haimin Wang, Jason T. L. Wang, Zhehui Wang, Kristian Wende, Xueqiao Xu, Hiroshi Yamada, Tatsuya Yokoyama, Xinhua Zhang
Summary: This review article focuses on data-driven plasma science (DDPS), highlighting its latest developments and progress. With plasma being the most common form of observable matter in the universe, data associated with plasmas cover large spatial and temporal scales and provide essential information for other scientific disciplines. Technological advancements have resulted in a large amount of data from plasma experiments, observations, and computation, necessitating the use of high-performance computers and artificial intelligence for data analysis in DDPS.
IEEE TRANSACTIONS ON PLASMA SCIENCE
(2023)