Search

Your search keyword '"A, Pradalier"' showing total 133 results
Start Over Author "A, Pradalier" Publisher iop publishing
133 results on '"A, Pradalier"'

1. WEST full tungsten operation with an ITER grade divertor

Author

J. Bucalossi, A. Ekedahl, and the WEST Team, J. Achard, K. Afonin, O. Agullo, T. Alarcon, L. Allegretti, F. Almuhisen, H. Ancher, G. Antar, Y. Anquetin, S. Antusch, V. Anzallo, C. Arnas, J.F. Artaud, M.H. Aumeunier, S.G. Baek, X.Y. Bai, M. Balden, C. Balorin, T. Barbui, A. Barbuti, J. Barlerin, J. Barra, V. Basiuk, T. Batal, O. Baulaigue, A. Bec, M. Becoulet, E. Benoit, E. Bernard, J.M. Bernard, M. Bernert, N. Bertelli, E. Bertrand, P. Beyer, J. Bielecki, P. Bienvenu, R. Bisson, B. Bliewert, G. Bodner, S. Bose, C. Bottereau, C. Bouchand, Y. Boumendjel, F. Bouquey, C. Bourdelle, J. Bourg, S. Brezinsek, F. Brochard, C. Brun, V. Bruno, H. Bufferand, A. Bureau, S. Burles, Y. Camenen, B. Cantone, E. Caprin, M. Carole, S. Carpentier-Chouchana, G. Caulier, F. Causa, N. Cazanave, N. Chanet, O. Chellai, Y. Chen, M. Chernyshova, P. Chmielewski, W. Choe, A. Chomiczewska, G. Ciraolo, F. Clairet, J. Coenen, L. Colas, G. Colledani, J. Colnel, P. Coquillat, E. Corbel, Y. Corre, X. Courtois, T. Czarski, A. Da Ros, R. Daniel, J. Daumas, M. De Combarieu, P. De Vries, C. Dechelle, F. Deguara, R. Dejarnac, J.M. Delaplanche, L.F. Delgado-Aparicio, E. Delmas, L. Delpech, C. Desgranges, P. Devynck, J. Denis, S. Di Genova, R. Diab, A. Diallo, M. Diez, G. Dif-Pradalier, M. Dimitrova, R. Ding, T. Dittmar, L. Doceul, M. Domenes, D. Donovan, D. Douai, L. Dubus, N. Dumas, R. Dumont, F. Durand, A. Durif, F. Durodié, D. Elbeze, S. Ertmer, A. Escarguel, F. Escourbiac, B. Esposito, K. Ezato, F. Faisse, J.L. Farjon, N. Faure, N. Fedorczak, P. Fejoz, F. Felici, C. Fenzi-Bonizec, F. Ferlay, L. Ferrand, L. Fevre, M. Firdaouss, L. Fleury, D. Flouquet, T. Fonghetti, A. Gallo, X. Garbet, J. Garcia, J.L. Gardarein, L. Gargiulo, P. Garibaldi, S. Garitta, J. Gaspar, E. Gauthier, S. Gazzotti, F. Gely, J. Gerardin, G. Gervasini, E. Geulin, M. Geynet, P. Ghendrih, I. Giacalone, C. Gil, S. Ginoux, S. Girard, E. Giroux, G. Giruzzi, M. Goniche, V. Gorse, T. Gray, E. Grelier, C. Grisolia, A. Grosjean, A. Grosman, O. Grover, D. Guibert, D. Guilhem, C. Guillemaut, B. Guillermin, R. Guirlet, J.P. Gunn, Y. Gunsu, T. Gyergyek, S. Hacquin, A. Hakola, J. Harris, J.C. Hatchressian, W. Helou, P. Hennequin, C. Hernandez, L. Hijazi, J. Hillairet, T. Hirai, G.T. Hoang, C. Honoré, M. Houry, A. Huart, G. Huijsmans, P. Huynh, M. Iafrati, F. Imbeaux, N. Imbert, I. Ivanova-Stanik, P. Ivanova, R. Jalageas, A. Jamann, C. Jammes, A. Jardin, L. Jaubert, G. Jiolat, E. Joffrin, C. Johnson, A. Jonas, A. Kirschner, C.C. Klepper, M. Komm, M. Koubiti, S. Kosslow, J. Kovacic, M. Kozeiha, K. Krieger, K. Krol, I. Kudashev, B. Lacroix, L. Laguardia, V. Lamaison, V. Lapleigne, H. Laqua, C. Lau, Y. Lausenaz, R. Lé, M. Le Bohec, N. Lefevre, N. Lemoine, E. Lerche, Y. Lesourd, L. Letellier, M. Lewerentz, Y. Li, A. Liang, P. Linczuk, C. Linsmeier, M. Lipa, X. Litaudon, X. Liu, J. Llorens, T. Loarer, A. Loarte, T. Loewenhoff, G. Lombard, J. Lore, P. Lorenzetto, B. Lu, A. Lumsdaine, R. Lunsford, T. Lunt, G. Luo, P. Magaud, P. Maget, J.F. Mahieu, P. Maini, P. Malard, K. Malinowski, P. Manas, L. Manenc, V. Maquet, Y. Marandet, C. Martin, E.J. Martin, P. Martino, M. Mayer, D. Mazon, S. Mazzi, P. Messina, L. Meunier, D. Midou, G. Miglionico, Y. Mineo, M. Missirlian, R. Mitteau, B. Mitu, D. Moiraf, P. Mollard, G. Momparler, V. Moncada, T. Mondiere, C. Monti, J. Morales, M. Moreau, Ph. Moreau, Y. Moudden, G. Moureau, D. Mouyon, M. Muraglia, T. Nakano, E. Nardon, A. Neff, F. Nespoli, J. Nichols, L. Nicolas, S. Nicollet, R. Nouailletas, M. Ono, V. Ostuni, O. Paillat, C. Parish, H. Park, H. Parrat, J.Y. Pascal, B. Pegourie, F.P. Pellissier, Y. Peneliau, M. Peret, E. Pignoly, G. Pintsuk, R. Pitts, C. Pocheau, A. Podolnik, C. Portafaix, M. Poulos, P. Prochet, A. Puig Sitjes, R. Ragona, M. Rasinski, S. Ratynskaia, G. Raup, X. Regal-Mezin, C. Reux, J. Rice, M. Richou, F. Rigollet, N. Rivals, H. Roche, S. Rodrigues, J. Romazanov, G. Ronchi, C. Ruset, R. Sabot, A. Saille, R. Sakamoto, B. Salamon, F. Samaille, A. Santagiustina, B. Santraine, Y. Sarazin, O. Sauter, Y. Savoie-Peysson, L. Schiesko, M. Scholz, J.L. Schwob, E. Serre, H. Shin, S. Shiraiwa, Ja. Signoret, O. Skalli-Fettachi, P. Sogorb, Y. Song, A. Spring, P. Spuig, S. Sridhar, B. Stratton, C. Talatizi, P. Tamain, R. Tatali, Q. Tichit, A. Torre, L. Toulouse, W. Treutterer, E. Tsitrone, E.A. Unterberg, G. Urbanczyk, G. Van Rooij, N. Varadarajan, S. Vartanian, E. Velly, J.M. Verger, L. Vermare, D. Vezinet, N. Vignal, B. Vincent, S. Vives, D. Volpe, G. Wallace, E. Wang, L. Wang, Y. Wang, Y.S. Wang, T. Wauters, D. Weldon, B. Wirth, M. Wirtz, A. Wojenski, M. Xu, Q.X. Yang, H. Yang, B. Zago, R. Zagorski, B. Zhang, X.J. Zhang, X.L. Zou, and the EUROfusion Tokamak Exploitation Team

Subjects
nuclear fusion, magnetic confinement, tokamak, divertor, WEST, ITER, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

The mission of WEST (tungsten-W Environment in Steady-state Tokamak) is to explore long pulse operation in a full tungsten (W) environment for preparing next-step fusion devices (ITER and DEMO) with a focus on testing the ITER actively cooled W divertor in tokamak conditions. Following the successful completion of phase 1 (2016-2021), phase 2 started in December 2022 with the lower divertor made entirely of actively cooled ITER-grade tungsten mono-blocks. A boronization prior the first plasma attempt allowed for a smooth startup with the new divertor. Despite the reduced operating window due to tungsten, rapid progress has been made in long pulse operation, resulting in discharges with a pulse length of 100 s and an injected energy of around 300 MJ per discharge. Plasma startup studies were carried out with equatorial boron nitride limiters to compare them with tungsten limiters, while Ion Cyclotron Resonance Heating assisted startup was attempted. High fluence operation in attached regime, which was the main thrust of the first campaigns, already showed the progressive build up of deposits and appearance of dust, impacting the plasma operation as the plasma fluence increased. In total, the cumulated injected energy during the first campaigns reached 43 GJ and the cumulated plasma time exceeded 5 h. Demonstration of controlled X-Point Radiator regime is also reported, opening a promising route for investigating plasma exhaust and plasma-wall interaction issues in more detached regime. This paper summarises the lessons learned from the manufacturing and the first operation of the ITER-grade divertor, describing the progress achieved in optimising operation in a full W environment with a focus on long pulse operation and plasma wall interaction.

Published
2024
Full Text
View/download PDF

2. Kinetic plasma-sheath self-organization

Author

Yann Munschy, Emily Bourne, Guilhem Dif-Pradalier, Peter Donnel, Philippe Ghendrih, Virginie Grandgirard, and Yanick Sarazin

Subjects
kinetic plasma wall interaction, kinetic numerical simulations, scrape-off layer physics, fluid equations closure, plasma wall self organization, kinetic plasma sheath, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

The interaction between a plasma and a solid surface is studied in a (1D–1V) kinetic framework using a localized particle and convective energy source. Matching the quasineutral plasma region and sheath horizon is addressed in the fluid framework with a zero heat flux closure. It highlights non-polytropic nature of the physics of parallel transport. Shortfalls of this approach compared to a reference kinetic simulation highlight the importance of the heat flux as the measure of kinetic effects. Non-collisional closure and higher moment closure are used to determine the sound velocity. Within these frameworks, no gain in the fluid predictive capability is obtained. The kinetic constraint at the sheath horizon is discussed and modified to account for conditions that are actually met in simulations, namely quasineutrality with a small but finite charge density. Analyzing the distribution functions shows that collisional transfer is mandatory to achieve steady-state self-organization on the open field lines.

Published
2024
Full Text
View/download PDF

3. Kinetic plasma-wall interaction using immersed boundary conditions

Author

Yann Munschy, Emily Bourne, Guilhem Dif-Pradalier, Peter Donnel, Philippe Ghendrih, Virginie Grandgirard, and Yanick Sarazin

Subjects
Vlasov-Poisson system, immersed boundary conditions, penalization, gyrokinetics, kinetic sheath, kinetic plasma wall interaction, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

The interaction between a plasma and a solid surface is studied in a (1D-1V) kinetic approach using immersed boundary conditions and penalization to model the wall. Two solutions for the penalized wall region are investigated that either allow currents to flow within the material boundary or not. Essential kinetic aspects of sheath physics are recovered in both cases and their parametric dependencies investigated. Importantly, we show how the two approaches can be reconciled when accounting for relevant kinetic effects. Non-Maxwellian features of the ion and electron distribution functions are essential to capture the value of the potential drop in the sheath. These features lead to a sheath heat transmission factor for ions 60% larger than usually predicted and 35% for electrons. The role of collisions is discussed and means of incorporating minimally-relevant kinetic sheath physics in the gyrokinetic framework are discussed.

Published
2024
Full Text
View/download PDF

4. The effect of shaping on trapped electron mode stability: an analytical model

Author

X. Garbet, P. Donnel, L. De Gianni, Z. Qu, Y. Melka, Y. Sarazin, V. Grandgirard, K. Obrejan, E. Bourne, and G. Dif-Pradalier

Subjects
magnetic fusion energy, stability, trapped electron modes, shaping, negative triangularity, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

A reduced model for trapped electron mode stability has been developed, which incorporates the basic effects of magnetic surface shaping, in particular, elongation and triangularity. This model shows that while elongation is stabilising, though weakly, negative triangularity usually leads to a more unstable plasma. This is in marked contrast with the experimental evidence of a better confinement at negative triangularity, and with recent gyrokinetic linear simulations. This paradox is solved when finite orbit and/or finite mode extent along field lines (mode ballooning) effects are included. These effects give more weight to particles trapped at low bounce angles, which are those that exhibit lower precession frequencies at negative—compared to positive—triangularity. As a result, the interchange growth rate becomes lower at negative triangularity and large temperature gradients, so that negative triangularity appears to have an overall stabilising effect. Mode ballooning appears to play the most important role in this reversal of stability.

Published
2024
Full Text
View/download PDF

6. Kinetic plasma-sheath self-organization

Author

Munschy, Yann, primary, Bourne, Emily, additional, Dif-Pradalier, Guilhem, additional, Donnel, Peter, additional, Ghendrih, Philippe, additional, Grandgirard, Virginie, additional, and Sarazin, Yanick, additional

Published
2024
Full Text
View/download PDF

7. Safety factor influence on the edge E  ×  B velocity establishment in tokamak plasmas.

Author

Varennes, R, Vermare, L, Garbet, X, Hennequin, P, Dif-Pradalier, G, Sarazin, Y, Grandgirard, V, Panico, O, Donnel, P, and Obrejan, K

Subjects
SAFETY factor in engineering, PLASMA turbulence, TOKAMAKS, VELOCITY, ION temperature, REYNOLDS stress, ELECTRIC fields
Abstract

This study is motivated by experiments on Tore Supra and WEST tokamaks where a deepening of the E × B velocity—governed by the radial electric field Er —near the edge is observed when the safety factor decreases in L-mode plasmas. Flux-driven global simulations of ion temperature gradient turbulence recover qualitatively the trend observed in the experiments, i.e. the E × B velocity increases when decreasing the safety factor. From these simulations, multiple clues point out the role of turbulence in the establishment of the radial electric field even though the turbulent intensity increases with the safety factor. The proposed mechanism to elucidate this phenomenon, backed up by a reduced model, is that the damping of the poloidal flow, governed by the neoclassical friction, increases more strongly with the safety factor than the turbulent drive for Er, due to the (r , θ) component of the Reynolds stress. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

8. The problem of capturing marginality in model reductions of turbulence

Author

Gillot, C, primary, Dif-Pradalier, G, additional, Sarazin, Y, additional, Bourdelle, C, additional, Bañón Navarro, A, additional, Camenen, Y, additional, Citrin, J, additional, Di Siena, A, additional, Garbet, X, additional, Ghendrih, Ph, additional, Grandgirard, V, additional, Manas, P, additional, and Widmer, F, additional

Published
2023
Full Text
View/download PDF

10. Role of avalanche transport in competing drift wave and interchange turbulence

Author

Ghendrih, Philippe, primary, Dif-Pradalier, Guilhem, additional, Panico, Olivier, additional, Sarazin, Yanick, additional, Bufferand, Hugo, additional, Ciraolo, Guido, additional, Donnel, Peter, additional, Fedorczak, Nicolas, additional, Garbet, Xavier, additional, Grandgirard, Virginie, additional, Hennequin, Pascale, additional, Serre, Eric, additional, and Tamain, Patrick, additional

Published
2022
Full Text
View/download PDF

12. Formation of the radial electric field profile in the WEST tokamak

Author

Vermare, L., primary, Hennequin, P., additional, Honoré, C., additional, Peret, M., additional, Dif-Pradalier, G., additional, Garbet, X., additional, Gunn, J., additional, Bourdelle, C., additional, Clairet, F., additional, Morales, J., additional, Dumont, R., additional, Goniche, M., additional, Maget, P., additional, Varennes, R., additional, and WEST Team, the, additional

Published
2021
Full Text
View/download PDF

13. Impact of poloidal convective cells on momentum flux in tokamaks

Author

X Garbet, Y Asahi, P Donnel, C Ehrlacher, G Dif-Pradalier, P Ghendrih, V Grandgirard, and Y Sarazin

Subjects
plasma physics, turbulence, tokamaks, Science, Physics, QC1-999
Abstract

Radial fluxes of parallel momentum due to $E\times B$ and magnetic drifts are shown to be correlated in tokamak plasmas. This correlation comes from the onset of poloidal convective cells generated by turbulence. The entire process requires a symmetry breaking mechanism, e.g. a mean shear flow. An analytical calculation shows that anti-correlation between the poloidal and parallel components of the turbulent Reynolds stress results in anti-correlation of the fluxes of parallel momentum generated by $E\times B$ and curvature drifts.

Published
2017
Full Text
View/download PDF

15. Zonal instability and wave trapping

Author

Garbet, X., primary, Panico, O., additional, Varennes, R., additional, Gillot, C., additional, Dif-Pradalier, G., additional, Sarazin, Y., additional, Bourne, E., additional, Grandgirard, V., additional, Ghendrih, P., additional, Zarzoso, D., additional, and Vermare, L., additional

Published
2021
Full Text
View/download PDF

16. Formation of the radial electric field profile in the WEST tokamak.

Author

Vermare, L., Hennequin, P., Honoré, C., Peret, M., Dif-Pradalier, G., Garbet, X., Gunn, J., Bourdelle, C., Clairet, F., Morales, J., Dumont, R., Goniche, M., Maget, P., Varennes, R., and WEST Team, the

Subjects
ELECTRIC fields, TOKAMAKS, PLASMA turbulence, PLASMA currents, PLASMA boundary layers, ELECTRORHEOLOGY, VELOCITY
Abstract

Sheared flows are known to reduce turbulent transport by decreasing the correlation length and/or intensity of turbulent structures. The transport barrier that takes place at the edge during improved regimes such as H mode, corresponds to the establishment of a large shear of the radial electric field. In this context, the radial shape of the radial electric field or more exactly of the perpendicular E Ă— B velocity appears as a key element in accessing improved confinement regimes. In this paper, we present the radial profile of the perpendicular velocity measured using Doppler back-scattering system at the edge of the plasma, dominated by the E Ă— B velocity, during the first campaigns of the WEST tokamak. It is found that the radial velocity profile is clearly more sheared in lower single null configuration (with the B Ă— ∇ B magnetic drift pointing toward the active X -point) than in upper single null configuration for ohmic and low current plasmas (B = 3.7 T and q 95 = 4.7), consistently with the expectation comparing respectively ‘favourable’ versus ‘unfavourable’ configuration. Interestingly, this tendency is sensitive to the plasma current and to the amount of additional heating power leading to plasma conditions in which the E Ă— B velocity exhibits a deeper well in USN configuration. For example, while the velocity profile exhibits a clear and deep well just inside the separatrix concomitant with the formation of a density pedestal during Lâ€"H transitions observed in LSN configuration, deeper E r wells are observed in USN configuration during similar transitions with less pronounced density pedestal. [ABSTRACT FROM AUTHOR]

Published
2022
Full Text
View/download PDF

20. Generation and dynamics of SOL corrugated profiles

Author

Ghendrih, P., primary, Asahi, Y., additional, Caschera, E., additional, Dif-Pradalier, G., additional, Donnel, P., additional, Garbet, X., additional, Gillot, C., additional, Grandgirard, V., additional, Latu, G., additional, Sarazin, Y., additional, Baschetti, S., additional, Bufferand, H., additional, Cartier-Michaud, T., additional, Ciraolo, G., additional, Tamain, P., additional, Tatali, R., additional, and Serre, E., additional

Published
2018
Full Text
View/download PDF

23. Immersed boundary conditions in global, flux-driven, gyrokinetic simulations

Author

G. Latu, E. Caschera, Ph. Ghendrih, Nicolas Bouzat, Xavier Garbet, Yanick Sarazin, P. Donnel, V. Grandgirard, Yuuichi Asahi, C. Passeron, and G. Dif-Pradalier

Subjects
Physics, History, 0103 physical sciences, Boundary value problem, Mechanics, 010306 general physics, 01 natural sciences, Flux (metabolism), 010305 fluids & plasmas, Computer Science Applications, Education
Published
2018

24. Generation and dynamics of SOL corrugated profiles

Author

C. Gillot, Yanick Sarazin, G. Latu, Xavier Garbet, Yuuichi Asahi, G. Ciraolo, G. Dif-Pradalier, T. Cartier-Michaud, H. Bufferand, P. Donnel, Philippe Ghendrih, Eric Serre, S. Baschetti, V. Grandgirard, Patrick Tamain, Raffaele Tatali, E. Caschera, CEA Cadarache, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), National Institutes for Quantum and Radiological Science and Technology (QST), Institut de Recherche sur la Fusion par confinement Magnétique (IRFM), Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de Mécanique, Modélisation et Procédés Propres (M2P2), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.PHYS.PHYS-FLU-DYN]Physics [physics]/Physics [physics]/Fluid Dynamics [physics.flu-dyn], [PHYS.PHYS.PHYS-CLASS-PH]Physics [physics]/Physics [physics]/Classical Physics [physics.class-ph], History, Materials science, Scale (ratio), Kinetic energy, 01 natural sciences, 010305 fluids & plasmas, Education, [PHYS.PHYS.PHYS-COMP-PH]Physics [physics]/Physics [physics]/Computational Physics [physics.comp-ph], Physics::Fluid Dynamics, [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], Physics::Plasma Physics, 0103 physical sciences, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], [PHYS.COND.CM-SM]Physics [physics]/Condensed Matter [cond-mat]/Statistical Mechanics [cond-mat.stat-mech], 010306 general physics, Turbulence, Dynamics (mechanics), Magnetic confinement fusion, Spectral density, Mechanics, Plasma, Computer Science Applications, Complex dynamics, Physics::Space Physics
Abstract

International audience; The staircase transport regime reported in kinetic simulations of plasma turbulent transport in magnetic confinement is recovered with a simple 2D fluid model allowing for reduced damping of the zonal flows. Some of the complex dynamics of the kinetic zonation regime are recovered but the pattern of the corrugation appears to be sinusoidal with a characteristic scale comparable to that of turbulence modes with largest spectral energy, in contrast to regimes observed in global and flux-driven kinetic simulations. Enhanced zonal flows govern both an overall reduction of the SOL width and a gradual steepening of the gradients with distance to the separatrix.

Published
2018

25. Self-consistent gyrokinetic modeling of neoclassical and turbulent impurity transport

Author

Estève, D., primary, Sarazin, Y., additional, Garbet, X., additional, Grandgirard, V., additional, Breton, S., additional, Donnel, P., additional, Asahi, Y., additional, Bourdelle, C., additional, Dif-Pradalier, G., additional, Ehrlacher, C., additional, Emeriau, C., additional, Ghendrih, Ph., additional, Gillot, C., additional, Latu, G., additional, and Passeron, C., additional

Published
2018
Full Text
View/download PDF

28. Global full-fgyrokinetic simulations of plasma turbulence

Author

Ph. Ghendrih, Guilhem Dif-Pradalier, Alberto Bottino, Eric Sonnendrücker, Nicolas Crouseilles, Yanick Sarazin, Virginie Grandgirard, Laurent Villard, Guillaume Latu, Xavier Garbet, Paolo Angelino, G. Darmet, and S. Jolliet

Subjects
Physics, Tokamak, Turbulence, Charge separation, Plasma turbulence, Linear threshold, Condensed Matter Physics, Polarization (waves), Curvature, law.invention, Nuclear Energy and Engineering, law, Statistical physics, Scaling
Abstract

Critical physical issues can be specifically tackled with the global full-f gyrokinetic code GYSELA. Three main results are presented. First, the self-consistent treatment of equilibrium and fluctuations highlights the competition between two compensation mechanisms for the curvature driven vertical charge separation, namely, parallel flow and polarization. The impact of the latter on the turbulent transport is discussed. In the non-linear regime, the benchmark with the Particle-In-Cell code ORB5 looks satisfactory. Second, the transport scaling with p. is found to depend both on p. itself and on the distance to the linear threshold. Finally, a statistical steady-state turbulent regime is achieved in a reduced version of GYSELA by prescribing a constant heat source.

Published
2007

30. WEST Physics Basis

Author

Marc Missirlian, Pascale Hennequin, M. Yoshida, T. Loarer, A. Ekedahl, J. Decker, Patrick Maget, M. Firdaouss, Sylvain Brémond, Irena Ivanova-Stanik, E. Tsitrone, C. Grisolia, Lena Delpech, Marina Becoulet, C. Gil, X. Courtois, A. Kallenbach, Philippe Ghendrih, R. Zagórski, L. Colas, C. Fenzi, J.F. Artaud, T. Hoang, Roland Sabot, Guido Ciraolo, James Paul Gunn, Julien Hillairet, Frederic Imbeaux, P. Lotte, G. Giruzzi, P. Devynck, J. Garcia, P. Moreau, Patrick Mollard, Laure Vermare, M. Goniche, O. Meyer, Eric Nardon, Jérôme Bucalossi, B. Pégourié, R. J. Dumont, M. Schneider, P. Monier-Garbet, D. Douai, S. Vartanian, Yannick Marandet, Jochen Linke, Y. Peysson, Jet Contributors, J.-M. Travere, Clarisse Bourdelle, D. Guilhem, Hugo Bufferand, V. Basiuk, Yann Corre, R.P. Doerner, Guilhem Dif-Pradalier, F. Saint-Laurent, M.-L. Mayoral, Nicolas Fedorczak, A. Grosman, R. Guirlet, E. Joffrin, Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, Laboratoire de Physique des Plasmas (LPP), Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), IRFM-CEA, École Polytechnique Fedérale de Lausanne, VTT Technical Research Centre of Finland, Department of Applied Physics, Princeton University, Culham Science Centre, Uppsala University, European Commission, Chinese Academy of Sciences, National Fusion Research Institute, ITER, Universidad Politécnica de Madrid, School services,SCI, Sorbonne Université, Institute for Plasma Research, Universidade de Lisboa, Research Center Julich, University of Electronic Science and Technology of China, Aalto-yliopisto, Aalto University, and JET Contributors

Subjects
Nuclear and High Energy Physics, Long pulse, Tokamak, Nuclear engineering, TOKAMAKS, POWER, Tore Supra, PROFILE, 7. Clean energy, law.invention, Plasma physics, Pedestal, Divertor, law, [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], divertor, User Facility, ddc:530, tokamak, LOSSES, Plasma facing components, Physics, TUNGSTEN, plasma physics, EXTRAPOLATION, Plasma, Condensed Matter Physics, plasma facing components, DENSITY PEAKING, TRANSPORT, Heat flux, BEHAVIOR
Abstract

International audience; With WEST (Tungsten Environment in Steady State Tokamak) (Bucalossi et al 2014 Fusion Eng. Des. 89 [http://dx.doi.org/10.1016/j.fusengdes.2014.01.062] 907?12 ), the Tore Supra facility and team expertise (Dumont et al 2014 Plasma Phys. Control. Fusion 56 [http://dx.doi.org/10.1088/0741-3335/56/7/075020] 075020 ) is used to pave the way towards ITER divertor procurement and operation. It consists in implementing a divertor configuration and installing ITER-like actively cooled tungsten monoblocks in the Tore Supra tokamak, taking full benefit of its unique long-pulse capability. WEST is a user facility platform, open to all ITER partners. This paper describes the physics basis of WEST: the estimated heat flux on the divertor target, the planned heating schemes, the expected behaviour of the L?H threshold and of the pedestal and the potential W sources. A series of operating scenarios has been modelled, showing that ITER-relevant heat fluxes on the divertor can be achieved in WEST long pulse H-mode plasmas.

Published
2015

31. L to H mode transition: parametric dependencies of the temperature threshold

Author

Alexander Lukin, Stefan Matejcik, Soare Sorin, Francesco Romanelli, Emilio Blanco, Ephrem Delabie, Guilhem Dif-Pradalier, Bohdan Bieg, Fulvio Militello, Vladislav Plyusnin, José Vicente, Alberto Loarte, Rajnikant Makwana, CHIARA MARCHETTO, Marco Wischmeier, Choong-Seock Chang, Aneta Gójska, Laurent Chôné, Manuel Garcia-munoz, Laure Vermare, Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, Universidad de Sevilla. RNM138: Física Nuclear Aplicada, Institut de Recherche sur la Fusion par confinement Magnétique (IRFM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Physique des interactions ioniques et moléculaires (PIIM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Dutch Institute for Fundamental Energy Research [Nieuwegein] (DIFFER), Joint European Torus (JET-EFDA), Culham Science Centre [Abingdon], and Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)

Subjects
Physics, [PHYS]Physics [physics], Nuclear and High Energy Physics, Tokamak, Condensed matter physics, Turbulence, Plasma, Electron, Collisionality, Condensed Matter Physics, 01 natural sciences, Effective nuclear charge, 010305 fluids & plasmas, Magnetic field, law.invention, Plasma physics, law, Electric field, 0103 physical sciences, L H transition, Atomic physics, 010306 general physics
Abstract

International audience; The L to H mode transition occurs at a critical power which depends on ă various parameters, such as the magnetic field, the density, etc. ă Experimental evidence on various tokamaks (JET, ASDEX-Upgrade, DIII-D, ă Alcator C-Mod) points towards the existence of a critical temperature ă characterizing the transition. This criterion for the L-H transition is ă local and is therefore easier to be compared to theoretical approaches. ă In order to shed light on the mechanisms of the transition, simple ă theoretical ideas are used to derive a temperature threshold (T-th). ă They are based on the stabilization of the underlying turbulence by a ă mean radial electric field shear. The nature of the turbulence varies as ă the collisionality decreases, from resistive ballooning modes to ion ă temperature gradient and trapped electron modes. The obtained parametric ă dependencies of the derived T-th are tested versus magnetic field, ă density, effective charge. Various robust experimental observations are ă reproduced, in particular T-th increases with magnetic field B and ă increases with density below the density roll-over observed on the power ă threshold.

Published
2015

32. E×B staircases and barrier permeability in magnetised plasmas

Author

Grégoire Hornung, F. Clairet, Roland Sabot, Guilhem Dif-Pradalier, Yanick Sarazin, Geert Verdoolaege, Pascale Hennequin, Universiteit Gent = Ghent University [Belgium] (UGENT), Institut de Recherche sur la Fusion par confinement Magnétique (IRFM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de Physique des Plasmas (LPP), Université Paris-Saclay-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École polytechnique (X)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Laboratory for Plasma Physics (LPP), Ecole Royale Militaire / Koninklijke Militaire School (ERM KMS), The authors thank P.H. Diamond, Ph. Ghendrih, P. Lotte and the participants of the 2015 Festival de Théorie in Aix-en-Provence for stimulating discussions, as well as Eurofusion (WP14-ER-01) and IFERC-CSC for support., Universiteit Gent = Ghent University (UGENT), Université Paris-Sud - Paris 11 (UP11)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear and High Energy Physics, Tokamak, Condensed matter physics, Turbulence, Plasma, Tore Supra, Condensed Matter Physics, 01 natural sciences, 010305 fluids & plasmas, law.invention, Physics::Fluid Dynamics, [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], Physics::Plasma Physics, law, Permeability (electromagnetism), Physics::Space Physics, 0103 physical sciences, 010306 general physics, Shear flow, Reflectometry, Scaling
Abstract

In-depth experimental characterisation of spontaneous shear flow patterning into a so-called E × B staircase—named after its planetary analogue—is shown in magnetised plasma turbulence, using ultrafast-sweeping reflectometry in the Tore Supra tokamak. Staircase signatures are found in a large variety of L-mode plasma conditions. Sensitivity to the dominant source of free energy is highlighted for the first time. A connection between staircase shear layer permeability and deviation from gyro-Bohm confinement scaling is strongly suggested, opening new routes to understanding confinement in drift-wave turbulence.

Published
2016

36. Towards an emerging understanding of non-locality phenomena and non-local transport

Author

Ida, K., primary, Shi, Z., additional, Sun, H.J., additional, Inagaki, S., additional, Kamiya, K., additional, Rice, J.E., additional, Tamura, N., additional, Diamond, P.H., additional, Dif-Pradalier, G., additional, Zou, X.L., additional, Itoh, K., additional, Sugita, S., additional, Gürcan, O.D., additional, Estrada, T., additional, Hidalgo, C., additional, Hahm, T.S., additional, Field, A., additional, Ding, X.T., additional, Sakamoto, Y., additional, Oldenbürger, S., additional, Yoshinuma, M., additional, Kobayashi, T., additional, Jiang, M., additional, Hahn, S.H., additional, Jeon, Y.M., additional, Hong, S.H., additional, Kosuga, Y., additional, Dong, J., additional, and Itoh, S.-I., additional

Published
2015
Full Text
View/download PDF

38. Turbulent current drive

Author

Garbet, X, primary, Esteve, D, additional, Sarazin, Y, additional, Dif-Pradalier, G, additional, Ghendrih, P, additional, Grandgirard, V, additional, Latu, G, additional, and Smolyakov, A, additional

Published
2014
Full Text
View/download PDF

42. A FFT-based formulation for efficient mechanical fields computation in isotropic and anisotropic periodic discrete dislocation dynamics

Author

Cédric Pradalier, Nicolas Bertin, M. V. Upadhyay, and Laurent Capolungo

Subjects
Materials science, Classical mechanics, Mechanics of Materials, Modeling and Simulation, Computation, Isotropy, Dynamics (mechanics), Fast Fourier transform, General Materials Science, Condensed Matter Physics, Anisotropy, Discrete dislocation, Computer Science Applications
Published
2015

43. Scrape-off layer-induced beam density fluctuations and their effect on beam emission spectroscopy

Author

Patrick Tamain, David Moulton, Guilhem Dif-Pradalier, and Yannick Marandet

Subjects
Physics, Nuclear and High Energy Physics, Tokamak, Turbulence, Magnitude (mathematics), Condensed Matter Physics, law.invention, Core (optical fiber), Physics::Plasma Physics, law, Physics::Accelerator Physics, M squared, Emission spectrum, Pitch angle, Atomic physics, Beam (structure)
Abstract

A statistical model is presented to calculate the magnitude of beam density fluctuations generated by a turbulent scrape-off layer (SOL). It is shown that the SOL can induce neutral beam density fluctuations of a similar magnitude to the plasma density fluctuations in the core, potentially corrupting beam emission spectroscopy measurements. The degree of corruption is quantified by combining simulations of beam and plasma density fluctuations inside a simulated measurement window. A change in pitch angle from the separatrix to the measurement window is found to reduce the effect of beam fluctuations, whose largest effect is to significantly reduce the measured correlation time.

Published
2015

44. Self organisation of plasma turbulence: impact on radial correlation lengths

Author

Xavier Garbet, Philippe Ghendrih, D. Esteve, C. Passeron, Virginie Grandgirard, C. Norscini, Guillaume Latu, Yanick Sarazin, Guilhem Dif-Pradalier, and T. Cartier-Michaud

Subjects
Correlation, Physics, Shearing (physics), History, Self organisation, Plasma turbulence, Probability density function, Statistical physics, Granularity, Algebraic number, Scaling, Computer Science Applications, Education
Abstract

The empirical scaling law used to support the projected ITER performance [1, 2] in analysed to determine the control parameters that must be considered in gyrokinetic simulations. The results of such an analysis are contradictory and do not appear to fit with present evidence from gyrokinetic simulations. Analysing the dependence of the correlation length on the ρ* parameter, we show that local values of the correlation length are governed by the shearing effect of the corrugation patterns, but that coarse graining this value, in time, radially or poloidally does not allow one to recover this match. A comparison to the scaling law must then rely on the scaling properties of the Probability Density Function of the correlation length that is found to exhibit heavy tails with algebraic decay.

Published
2014

45. Turbulent current drive

Author

Philippe Ghendrih, G. Latu, V. Grandgirard, D. Esteve, Guilhem Dif-Pradalier, Xavier Garbet, Andrei Smolyakov, and Yanick Sarazin

Subjects
Physics, History, Turbulence, K-epsilon turbulence model, Mechanics, Electron, Computer Science Applications, Education, Physics::Fluid Dynamics, Momentum, Classical mechanics, Turbulence kinetic energy, Pinch, Symmetry breaking, Scaling
Abstract

The Ohm's law is modified when turbulent processes are accounted for. Besides an hyper-resistivity, already well known, pinch terms appear in the electron momentum flux. Moreover it appears that turbulence is responsible for a source term in the Ohm's law, called here turbulent current drive. Two terms contribute to this source. The first term is a residual stress in the momentum flux, while the second contribution is an electro-motive force. A non zero average parallel wave number is needed to get a finite source term. Hence a symmetry breaking mechanism must be invoked, as for ion momentum transport. E × B shear flows and turbulence intensity gradients are shown to provide similar contributions. Moreover this source term has to compete with the collision friction term (resistivity). The effect is found to be significant for a large scale turbulence in spite of an unfavorable scaling with the ratio of the electron to ion mass. Turbulent current drive appears to be a weak effect in the plasma core, but could be substantial in the plasma edge where it may produce up to 10 % of the local current density.

Published
2014

46. Staircase temperature profiles and plasma transport self-organisation in a minimum kinetic model of turbulence based on the trapped ion mode instability

Author

V. Grandgirard, Guilhem Dif-Pradalier, Yanick Sarazin, Thomas Drouot, Philippe Ghendrih, C. Passeron, G. Latu, Xavier Garbet, D. Esteve, C. Norscini, and T. Cartier-Michaud

Subjects
Physics, History, K-epsilon turbulence model, Turbulence, K-omega turbulence model, Plasma, Zonal flow (plasma), Mechanics, Parameter space, Instability, Computer Science Applications, Education, Physics::Plasma Physics, Quasiperiodic function, Physics::Space Physics, Statistical physics
Abstract

A minimum model of plasma turbulence in a kinetic framework is presented. It is based on trapped ion turbulence, gyro and bounce averaged, and implemented in the versatile and efficient code TERESA. Zonal flow - streamer interplay are readily shown to be key players that govern the confinement properties of the model. The parameter space of the model is explored with brute force numerics. A generic result is either a streamer dominated pattern with large transport, or a staircase temperature profile with very marked corrugations and quenched transport. A case with off-axis heating is found to exhibit quasiperiodic relaxation events relevant to investigate dynamical turbulence self-organisation.

Published
2014

48. Interplay between fast ions and turbulence in magnetic fusion plasmas

Author

Dumont, R J, primary, Zarzoso, D, additional, Sarazin, Y, additional, Garbet, X, additional, Strugarek, A, additional, Abiteboul, J, additional, Cartier-Michaud, T, additional, Dif-Pradalier, G, additional, Ghendrih, Ph, additional, Girardo, J-B, additional, Grandgirard, V, additional, Latu, G, additional, Passeron, C, additional, and Thomine, O, additional

Published
2013
Full Text
View/download PDF

49. Interplay between fast ions and turbulence in magnetic fusion plasmas

Author

David Zarzoso, Xavier Garbet, Antoine Strugarek, Guillaume Latu, J. Abiteboul, T. Cartier-Michaud, R. J. Dumont, Yanick Sarazin, Guilhem Dif-Pradalier, Ph. Ghendrih, C. Passeron, J. B. Girardo, Olivier Thomine, and V. Grandgirard

Subjects
Physics, Tokamak, Turbulence, Plasma, Condensed Matter Physics, Instability, Charged particle, Computational physics, Ion, law.invention, Physics::Fluid Dynamics, Distribution function, Nuclear Energy and Engineering, Physics::Plasma Physics, law, Physics::Space Physics, Atomic physics, Excitation
Abstract

Evidence for the impact of energetic particles (EPs) on turbulence is given in this paper. Firstly, the excitation of electrostatic instabilities in linear gyrokinetic simulations performed with the global GYSELA code by introducing distribution functions typical of fast ions in tokamak plasmas is presented. The obtained mode is unambiguously characterized as an EGAM, i.e. a geodesic acoustic mode (GAM) excited by EPs. The influence of EGAMs on turbulence and associated transport is then analyzed by implementing a source adapted to the inclusion of fast particle populations in non-linear simulations. This source successfully excites EGAMs in the presence of turbulence, which leads to a drastic reduction of the turbulent transport. However, this reduction is only transient; it is followed by an increase of the turbulent activity, characterized by a complex interaction between the EGAMs and the turbulence. In the subsequent steady-state regime, turbulent transport appears to be modulated at the EGAM frequency.

Published
2013

50. An overview of intrinsic torque and momentum transport bifurcations in toroidal plasmas

Author

Diamond, P.H., primary, Kosuga, Y., additional, Gürcan, Ö.D., additional, McDevitt, C.J., additional, Hahm, T.S., additional, Fedorczak, N., additional, Rice, J.E., additional, Wang, W.X., additional, Ku, S., additional, Kwon, J.M., additional, Dif-Pradalier, G., additional, Abiteboul, J., additional, Wang, L., additional, Ko, W.H., additional, Shi, Y.J., additional, Ida, K., additional, Solomon, W., additional, Jhang, H., additional, Kim, S.S., additional, Yi, S., additional, Ko, S.H., additional, Sarazin, Y., additional, Singh, R., additional, and Chang, C.S., additional

Published
2013
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results