Article
Physics, Fluids & Plasmas
Jianxun Su, Baonian Wan, Juan Huang, Birgitte Madsen, Mirko Salewski, Yanxu Sun, Jinfang Wang, Jing Fu, Jiafeng Chang, Chengrui Wu, Lizhen Liang, Yingjie Chen, Guoqiang Zhong, Haiqing Liu, Qing Zang, Yingying Li, Bo Lyu, Jinping Qian, Xianzu Gong
Summary: By combining data from two different views, the velocity-space distributions of fast ions on EAST have been reconstructed more accurately, with further studies planned to enhance the reliability of FIDA-based reconstructions in the future based on real multi-view measurements on EAST.
PLASMA SCIENCE & TECHNOLOGY
(2021)
Article
Physics, Fluids & Plasmas
P. Cano-Megias, E. Viezzer, J. Galdon-Quiroga, L. Sanchis, M. Garcia-Munoz, D. J. Cruz-Zabala, R. M. McDermott, J. F. Rivero-Rodriguez, A. Snicker, W. A. Suttrop, M. Willensdorfer
Summary: This paper studies the effect of 3D magnetic perturbations on fast-ion confinement and the toroidal rotation velocity profile. Two low collisionality H-mode experiments were analyzed, and differences in magnetic field helicity and fast-ion losses were observed. A new analysis technique was developed to investigate the dependencies between fast-ion losses and toroidal rotation, providing correlation patterns resolved in radius and velocity space. The study found that fast-ion transport and losses are influenced by beam geometry and magnetic field helicity, and resonant amplification leads to good agreement with experimental results.
Article
Physics, Fluids & Plasmas
H. E. Ferrari, R. Farengo, P. M. Garcia-Martinez, C. F. Clauser
Summary: In this study, the effect of NTMs on the confinement of energetic ions produced by NBI injection is examined using the FOCUS code. The main finding is that an increase in ion losses occurs when the frequency of the NTM matches the toroidal precession frequency of the trapped ions.
PLASMA PHYSICS AND CONTROLLED FUSION
(2023)
Article
Physics, Multidisciplinary
Yan-Xu Sun, Juan Huang, Wei Gao, Jia-Feng Chang, Wei Zhang, Chang Shi, Yun-He Li
Summary: In this research, the velocity-space tomography method is used to investigate the fast-ion velocity distribution function in fusion experiments. A high-accuracy tomographic inversion method is introduced to improve the inversion results by considering prior information and effectively mitigating artifacts. By combining different diagnostic methods, the precision of the obtained velocity distribution functions is enhanced, and the synergistic effect of heating on fast-ion distribution is validated. This study provides a foundation for more efficient heating methods in future fusion experiments.
ACTA PHYSICA SINICA
(2023)
Article
Physics, Fluids & Plasmas
J. Galdon-Quiroga, L. Sanchis-Sanchez, X. Chen, G. Birkenmeier, K. Gage, P. Cano-Megias, J. Gonzalez-Martin, W. W. Heidbrink, O. Putignano, D. Ryan, G. Suarez Lopez, B. Tal, M. A. VanZeeland, E. Viezzer, M. Willensdorfer
Summary: The impact of externally applied magnetic perturbations on fast-ion losses has been studied in ASDEX Upgrade tokamak using the LIBP technique. Different applied MP spectra result in fast-ion orbit displacement, which is independent of the beam source. The minimum displacement occurs at a specific phase difference, which is different from the minimum of the plasma boundary displacement. Simulation results capture the magnitude of orbit displacement and the importance of the toroidal spectrum of the perturbation, while not matching the dependence with the phase difference as observed in experimental measurements.
Article
Physics, Multidisciplinary
X. D. Du, M. A. Van Zeeland, W. W. Heidbrink, J. Gonzalez-Martin, K. Sarkimaki, A. Snicker, D. Lin, C. S. Collins, M. E. Austin, G. R. McKee, Z. Yan, Y. Todo, W. Wu
Summary: In the DIII-D tokamak, fast ion phase-space flow driven by Alfven eigenmodes (AEs) exhibits different trajectories in different regions and is influenced by energy. The flow trajectories in phase space align with the intersection lines of constant magnetic moment and constant E-(omega/n)P-zeta surfaces, indicating large-scale phase-space transport of fast ions at those points. This destructive flow behavior of fast ions is consistent with nonlinear hybrid kinetic-magnetohydrodynamics simulation, where ions transition between different flow trajectories for phase-space transport.
PHYSICAL REVIEW LETTERS
(2021)
Article
Astronomy & Astrophysics
Xingyu Zhu, Jiansen He, Die Duan, Daniel Verscharen, Christopher J. Owen, Andrey Fedorov, Philippe Louarn, Timothy S. Horbury
Summary: In this study, measurements from Solar Orbiter are analyzed and compared with theoretical predictions to explore the influence of proton beams on wave activity in the solar wind. It is found that the velocity distribution functions of protons can destabilize fast magnetosonic/whistler waves. The non-alignment of the velocity vectors of the core and the beam with the wave velocity is responsible for the wave growth/damping.
ASTROPHYSICAL JOURNAL
(2023)
Article
Physics, Fluids & Plasmas
K. R. Gage, X. Chen, M. Van Zeeland, W. W. Heidbrink, J. Hanson, B. Lyons, D. C. Pace, J. Galdon-Quiroga, M. Garcia-Munoz
Summary: The impact of n = 1 magnetic perturbations (MPs) on fast ion losses in DIII-D has been explored through the use of light ion beam probe technique. Various MP spectra have been studied to examine the effect of normalized beta, fin, and plasma response on the MPs. The magnetic data demonstrates that the plasma response to fin strongly relies on the phase difference in perturbation coils, ??UL.
Article
Instruments & Instrumentation
Y. M. Hou, H. Y. Zhou, W. Chen, B. L. Hao, Y. Liu, Z. B. Shi, Y. P. Zhang, X. R. Duan
Summary: The FIDA diagnostic is used in the HL-2A tokamak to detect D alpha light emitted by neutralized fast ions during neutral beam injection. A tangentially viewing FIDA is developed, achieving high temporal and transverse spatial resolutions. A second FIDA installation with oblique viewing is designed to minimize spectral contaminants.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Article
Instruments & Instrumentation
C. Chrystal, S. R. Haskey, K. H. Burrell, B. A. Grierson, C. S. Collins
Summary: Sixteen new tangential views were installed on the high-field side of the DIII-D tokamak in 2019, allowing for direct measurement of deuterium poloidal rotation and independent measurements of the radial electric field. These new measurements provide further validation of neoclassical poloidal rotation predictions.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2021)
Article
Nuclear Science & Technology
J. Hidalgo-Salaverri, J. Rueda-Rueda, J. Galdon-Quiroga, P. Cano-Megias, E. Viezzer, J. Garcia-Dominguez, D. Silvagni, M. Videla-Trevin, P. Oyola, J. Ayllon-Guerola, M. Garcia-Munoz, T. Happel
Summary: Fast-alpha losses in future fusion power plants are expected to follow the co- and counter-current directions and have been extensively studied at the ASDEX Upgrade tokamak in the co-current direction. A new RFILD detector has been designed to study the behaviour of counter-current fast-ion losses and expand our knowledge on different plasma modes.
FUSION ENGINEERING AND DESIGN
(2023)
Article
Chemistry, Multidisciplinary
Shuyue Li, Dongxu Yu, Jingyi Liu, Nan Chen, Zexiang Shen, Gang Chen, Shiyu Yao, Fei Du
Summary: An in situ electrochemical strategy is proposed to regulate the interlayer distance of layered NH4V4O10, revealing a close relationship between optimal performances and interlayer space.
Article
Physics, Fluids & Plasmas
Allen H. Boozer
Summary: This paper highlights the impact of computational design reliability on fusion strategy, as well as the urgency of deploying carbon-free energy sources due to the increase in carbon emissions.
Article
Physics, Fluids & Plasmas
Filippo Zonta, Lucia Sanchis, Eero Hirvijoki
Summary: The paper proposes a novel scheme to improve statistics of simulated fast-ion loss signals and power loads in fusion devices by using backward and forward Monte Carlo methods. By implementing this scheme to the ASCOT suite of codes, significant improvements in fast-ion simulations have been achieved for testing purposes.
Article
Instruments & Instrumentation
J. Gonzalez-Martin, M. Garcia-Munoz, B. Sieglin, A. Herrmann, T. Lunt, J. Ayllon-Guerola, J. Galdon-Quiroga, J. Hidalgo-Salaverri, A. Kovacsik, J. F. Rivero-Rodriguez, L. Sanchis, D. Silvagni, S. Zoletnik, J. Dominguez
Summary: In the ASDEX Upgrade tokamak, a poloidal array of scintillator-based Fast-Ion Loss Detectors (FILDs) has been installed, allowing real-time control and measurement of fast-ion losses using a magnetic coil system and fast collimator-slit sweeping. This enables radial profiling of fast-ion losses and localized internal plasma fluctuations, with quantitative comparison against electron cyclotron emission measurements.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2021)
Article
Materials Science, Multidisciplinary
Andreo Crnjac, Milko Jaksic, Matija Matijevic, Mauricio Rodriguez-Ramos, Michal Pomorski, Zdravko Siketic
Summary: The energy loss of protons in a 3.5 mu m thick single-crystal diamond membrane was determined using the transmission method. The stopping power of diamond was evaluated and compared with simulations, showing a slight overestimate of the simulated values. The mean ionization potential of carbon atoms in diamond was determined to be 81 +/- 4 eV.
DIAMOND AND RELATED MATERIALS
(2023)
Article
Physics, Nuclear
T. Rodriguez-Gonzalez, C. Guerrero, C. M. Baecker, J. Bauer, C. Baeumer, S. Brons, W. Jentzen, M. C. Jimenez-Ramos, M. A. Millan-Callado, C. Schoemers, B. Timmermann, J. M. Quesada, R. Capote
Summary: Two complementary experiments were conducted at proton treatment centers in Germany to measure the production cross sections of light positron emitters 11C, 13N, and 15O in proton-induced reactions on the main constituents of the human body (C, N, and O). These data are crucial for nuclear reaction model development and improving the accuracy of PET range verification in proton radiotherapy.
NUCLEAR DATA SHEETS
(2023)
Article
Physics, Fluids & Plasmas
R. Ochoukov, S. Sipila, R. Bilato, V. Bobkov, M. Dreval, M. Weiland, R. Dendy, H. Faugel, T. Johnson, A. Kappatou, Y. Kazakov, K. G. McClements, D. Moseev, M. Salewski, P. Schneider
Summary: High frequency Alfven eigenmodes in the ion cyclotron frequency range have been actively researched on the ASDEX Upgrade tokamak. These modes are beam-driven and can persist for the entire duration of the beam-on time window. They have sub-cyclotron frequencies and propagate in the counter-current/counter-injection direction. The observed expansion of excited modes by radio frequency-acceleration of beam-injected ions at the 3rd cyclotron harmonic is consistent with the global Alfven eigenmode behavior.
Article
Physics, Fluids & Plasmas
K. R. Gage, X. Chen, M. Van Zeeland, W. W. Heidbrink, J. Hanson, B. Lyons, D. C. Pace, J. Galdon-Quiroga, M. Garcia-Munoz
Summary: The impact of n = 1 magnetic perturbations (MPs) on fast ion losses in DIII-D has been explored through the use of light ion beam probe technique. Various MP spectra have been studied to examine the effect of normalized beta, fin, and plasma response on the MPs. The magnetic data demonstrates that the plasma response to fin strongly relies on the phase difference in perturbation coils, ??UL.
Article
Physics, Fluids & Plasmas
M. B. Dreval, S. E. Sharapov, M. Vallar, B. Labit, A. N. Karpushov, M. Garcia-Munoz, TCV Team
Summary: A forward modeling technique is developed to determine the characteristic features of observed MHD modes using soft X-ray diagnostics. The technique evaluates the poloidal mode numbers, radial location, and ballooning character of the MHD modes. The study involves modeling the poloidal mode structures and investigating the space structures of toroidal Alfven eigenmodes (TAEs). The technique provides an easier analysis of the observed TAE mode compared to similar techniques used in other devices.
PLASMA PHYSICS AND CONTROLLED FUSION
(2023)
Article
Physics, Fluids & Plasmas
M. Cecconello, I. J. Dolby, A. Sperduti, J. Rivero-Rodriguez, G. Ericsson, I Fitzgerald, S. Y. Allan, J. Voller, B. Honey, B. A. Nizar, S. D. Elmore
Summary: Spherical tokamaks play a crucial role in the design of future fusion reactors, particularly in areas such as divertor physics and fast ion physics. MAST Upgrade, through its upgraded and new fast ion diagnostics, provides detailed observations on the behavior of fast ions in various plasma scenarios. The upgraded neutron camera becomes one of the key tools, along with other fast ion diagnostics, for a more constrained modeling of fast ion dynamics in fusion reactor relevant scenarios.
PLASMA PHYSICS AND CONTROLLED FUSION
(2023)
Article
Chemistry, Physical
R. Viegas, J. Roser, L. Barrientos, M. Borja-Lloret, J. Casana, J. Garcia Lopez, M. C. Jimenez-Ramos, F. Hueso-Gonzalez, A. Ros, G. Llosa
Summary: The use of Compton cameras for medical imaging and hadron therapy monitoring has increased in the last decade due to the development of silicon photomultipliers. A Compton camera prototype, MACACOp, was designed and assembled for testing the performance of a novel readout electronics system in a Compton camera setup. Results showed improved time resolution and the ability to obtain small displacements of reconstructed spots, reinforcing the potential of the system as a monitoring device for hadron therapy.
RADIATION PHYSICS AND CHEMISTRY
(2023)
Article
Physics, Fluids & Plasmas
B. S. Schmidt, M. Salewski, D. Moseev, M. Baquero-Ruiz, P. C. Hansen, J. Eriksson, O. Ford, G. Gorini, H. O. Jarleblad, Ye Kazakov, D. Kulla, S. Lazerson, J. E. Mencke, D. Mykytchuk, M. Nocente, P. Poloskei, M. Rud, A. Snicker, L. Stagner, S. Aekaeslompolo
Summary: We calculate reconstructions of fast-ion phase-space distribution functions in fusion plasmas using synthetic projections. Different components and particle densities of fast-ion phase-space distribution functions originating from neutral beam injection at TCV and W7-X can be distinguished based on synthetic spectra of projected velocities. Additionally, we show that using a basis of slowing-down distribution functions is equivalent to regularization using slowing-down physics as prior information.
Article
Physics, Fluids & Plasmas
Haotian Chen, Liu Chen, Eleonora Viezzer, Manuel Garcia-Munoz, Jiquan Li
Summary: The hybrid gyrokinetic-fluid model for simulating low-frequency electromagnetic fluctuations is revisited, emphasizing the self-consistency between the gyrokinetic ordering and magnetohydrodynamic equations. The parallel electric field equation is found to be a Poisson-like equation in general. The balance between parallel electric field and electron pressure gradient must be accurately captured, and the ion parallel current correction is shown to be essential for the ion sound wave branch.
PLASMA PHYSICS AND CONTROLLED FUSION
(2023)
Article
Nuclear Science & Technology
E. Viezzer, M. E. Austin, M. Bernert, K. H. Burrell, P. Cano-Megias, X. Chen, D. J. Cruz-Zabala, S. Coda, M. Faitsch, O. Fevrier, L. Gil, C. Giroud, T. Happel, G. F. Harrer, A. E. Hubbard, J. W. Hughes, A. Kallenbach, B. Labit, A. Merle, H. Meyer, C. Paz-Soldan, P. Oyola, O. Sauter, M. Siccinio, D. Silvagni, E. R. Solano
Summary: One of the major challenges in achieving fusion energy is the development of a high-performance plasma core connected to a boundary solution. The high confinement mode (H-mode) offers a promising solution with its edge transport barrier, but it is also prone to edge localized modes (ELMs) that pose a threat to future fusion devices. Various alternative regimes, such as I-mode, QH-mode, EDA H-mode, and others, have been explored to provide a no-ELM or small-ELM solution for ITER and EU-DEMO. However, there are still knowledge gaps and further research is needed to validate their applicability.
NUCLEAR MATERIALS AND ENERGY
(2023)
Article
Nuclear Science & Technology
A. Mancini, L. Velarde, E. Viezzer, D. J. Cruz-Zabala, J. F. Rivero-Rodriguez, M. Garcia-Munoz, L. Sanchis, A. Snicker, J. Segado-Fernandez, J. Garcia-Dominguez, J. Hidalgo-Salaverri, P. Cano-Megias, M. Toscano-Jimenez
Summary: The SMART tokamak is a new spherical machine that is being constructed to study high plasma confinement regimes. It consists of three phases, reaching an inductive plasma current of over 500 kA, a toroidal magnetic field of 1 T, and a pulse length of 500 ms. The H-mode access will be ensured by using neutral beam injection as an external heating system.
FUSION ENGINEERING AND DESIGN
(2023)
Article
Physics, Fluids & Plasmas
M. Maslov, E. Lerche, F. Auriemma, E. Belli, C. Bourdelle, C. D. Challis, A. Chomiczewska, A. Dal Molin, J. Eriksson, J. Garcia, J. Hobirk, I. Ivanova-Stanik, Ph. Jacquet, A. Kappatou, Y. Kazakov, D. L. Keeling, D. B. King, V. Kiptily, K. Kirov, D. Kos, R. Lorenzini, E. de la Luna, C. F. Maggi, J. Mailloux, P. Mantica, M. Marin, G. Matthews, I. Monakhov, M. Nocente, G. Pucella, D. Rigamonti, F. Rimini, S. Saarelma, M. Salewski, E. R. Solano, Z. Stancar, G. Stankunas, H. Sun, M. Tardocchi, D. Van Eester
Summary: In JET deuterium-tritium (D-T) plasmas, fusion power is generated through thermonuclear reactions and reactions between thermal ions and fast particles. A scenario with dominant non-thermal reactivity has been developed, resulting in high fusion power and validating predictive models.
Article
Physics, Fluids & Plasmas
S. E. Sharapov, H. J. C. Oliver, J. Garcia, D. L. Keeling, M. Dreval, V. Goloborod'Ko, Ye. O. Kazakov, V. G. Kiptily, Z. Stancar, P. J. Bonofiglo, R. Coelho, T. Craciunescu, J. Ferreira, A. Figueiredo, N. Fil, M. Fitzgerald, F. Nabais, M. Nocente, P. G. Puglia, J. Rivero-Rodriguez, P. Rodrigues, M. Salewski, R. A. Tinguely, L. E. Zakharov, JET Contributors
Summary: Dedicated experiments were conducted in JET DTE2 plasmas to create an alpha-particle bump-on-tail distribution and excite Alfven eigenmodes (AEs). Neutral beam injection-only heating with modulated power was used to modulate the alpha-particle source and sustain the bump-on-tail distribution. High-frequency modes in the TAE frequency range and multiple short-lived modes in a wider frequency range were detected with interferometry, soft x-ray cameras, and reflectometry. Analysis and modeling studies confirmed the characteristics and driving mechanisms of these modes.
Article
Physics, Applied
Wei Liu, Vsevolod Ivanov, Kaushalya Jhuria, Qing Ji, Arun Persaud, Walid Redjem, Jacopo Simoni, Yertay Zhiyenbayev, Boubacar Kante, Javier Garcia Lopez, Liang Z. Tan, Thomas Schenkel
Summary: Research shows that G color centers in silicon can be more efficiently formed by pulsed-proton irradiation, optimizing the ratio of G-center formation to nonradiative defect accumulation. The line width of G centers significantly broadens as the pulsed-proton fluence increases, indicating vacancy or interstitial clustering by overlapping collision cascades. Tracking the properties of G centers under various irradiation conditions enables sensitive probing of atomic disorder, serving as a complementary analytical method for sensing damage accumulation.
PHYSICAL REVIEW APPLIED
(2023)
