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1. 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
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2. 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
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3. The problem of capturing marginality in model reductions of turbulence

Author: C Gillot, G Dif-Pradalier, Y Sarazin, C Bourdelle, A Bañón Navarro, Y Camenen, J Citrin, A Di Siena, X Garbet, Ph Ghendrih, V Grandgirard, P Manas, and F Widmer
Subjects: Nuclear Energy and Engineering, Condensed Matter Physics
Abstract: Reduced quasilinear and nonlinear (gradient-driven) models with scale separations, commonly used to interpret experiments and to forecast turbulent transport levels in magnetised plasmas, are tested against nonlinear models without scale separations (flux-driven). Two distinct regimes of turbulence—either above threshold or near marginal stability—are investigated with Boltzmann electrons. The success of reduced models hinges in particular on the reproduction of nonlinear fluxes. Good agreement between models is found above threshold, whilst reduced models significantly underpredict fluxes near marginality, overlooking mesoscale flow organisation and turbulence self-advection. Constructive prescriptions whereby to improve reduced models are discussed.
Published: 2023

4. Global linear stability analysis of kinetic Trapped Ion Mode (TIM) in tokamak plasma using spectral method

Author: D Mandal, M Lesur, E Gravier, J N Sama, A Guillevic, Y Sarazin, X Garbet, Institut Jean Lamour (IJL), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche sur la Fusion par confinement Magnétique (IRFM), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
Subjects: gyrokinetic theory and simulation, [PHYS]Physics [physics], Nuclear Energy and Engineering, linear stability analysis, spectral method, trapped ion mode instability, Condensed Matter Physics, drift wave turbulence, electrostatic turbulence, turbulence in tokamak
Abstract: Trapped ion modes (TIMs) belong to the family of ion temperature gradient (ITG) modes, which are one of the important ingredients in heat turbulent transport at the ion scale in tokamak plasmas. A global linear analysis of a reduced gyro-bounce kinetic model for trapped particle modes is performed, and a spectral method is proposed to solve the dispersion relation. Importantly, the radial profile of the particle drift velocity is taken into account in the linear analysis by considering the magnetic flux ψ dependency of the equilibrium Hamiltonian H e q ( ψ ) in both the quasi-neutrality equation and equilibrium gyro-bounce averaged distribution function F e q . Using this spectral method, linear growth rates of TIM instability in the presence of different temperature profiles and precession frequencies of trapped ions, with an approximated constant Hamiltonian and the exact ψ dependent equilibrium Hamiltonian, are investigated. The growth rate depends on the logarithmic gradient of temperature κ T , density κ n and equilibrium Hamiltonian κ Λ . With the exact ψ dependent Hamiltonian, the growth rates and potential profiles are modified significantly, compared to the cases with an approximated constant Hamiltonian. All the results from the global linear analysis agree with a semi-Lagrangian based linear Vlasov solver with good accuracy. This spectral method is very fast and requires much less computation resources compared to a linear version of the Vlasov-solver based on a semi-Lagrangian scheme.
Published: 2023
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5. Gyrokinetic turbulence studies of the transition from open to closed field lines in tokamaks

Author: Donnel, Peter, Dif Pradalier, G., G. Di, Giannatale, Villard, L., V., Grandgirard, Nguyen, L., K., Obrejan, E., Bourne, X., Garbet, P., Ghendrih, Munschy, Yann, Y., Sarazin, R., Varennes, Institut de Recherche sur la Fusion par confinement Magnétique (IRFM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Swiss Plasma Center (SPC), Ecole Polytechnique Fédérale de Lausanne (EPFL), DAM Île-de-France (DAM/DIF), Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and icard, valerie
Subjects: [PHYS]Physics [physics], [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], [PHYS.PHYS.PHYS-PLASM-PH] Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], [PHYS] Physics [physics]
Abstract: International audience
Published: 2022

6. Impact of magnetic ripple on neoclassical equilibrium in gyrokinetic simulations

Author: R Varennes, X Garbet, L Vermare, Y Sarazin, G Dif-Pradalier, V Grandgirard, P Ghendrih, P Donnel, M Peret, K Obrejan, E Bourne, 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), Observatoire de Paris, 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), and Varennes, Robin
Subjects: stochastic transport, Nuclear Energy and Engineering, neoclassical transport, [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], [PHYS.PHYS.PHYS-PLASM-PH] Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], plasma flow, Condensed Matter Physics
Abstract: The effect of magnetic field ripple on tokamak plasma without turbulence is studied numerically and augmented with a reduced analytical model that includes neoclassical processes in the presence of non-axisymmetric perturbation and stochastic transport. For this study, a magnetic field ripple perturbation has been implemented in the GYSELA gyrokinetic code. This implementation has been verified thanks to a test of toroidal angular momentum conservation. The GYSELA code was then successfully benchmarked against the NEO code, which solves the drift kinetic equation, and against the reduced model in the collisionality range ν ⋆ ∈ [0.05–0.5] for several amplitudes of the magnetic ripple. An observation, shared by the model, the NEO code and GYSELA simulations is that the thermal drive of the mean poloidal velocity—measured by the k V P coefficient—decreases sharply for large yet experimentally relevant magnetic ripple amplitudes, and may even change sign.
Published: 2022

7. Transport barrier in 5D gyrokinetic flux-driven simulations

Author: G. Lo-Cascio, E. Gravier, T. Réveillé, M. Lesur, Y. Sarazin, X. Garbet, L. Vermare, K. Lim, A. Guillevic, V. Grandgirard, Institut Jean Lamour (IJL), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), CEA Cadarache, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, 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), CMCS-EPFL (CMCS-EPFL), Ecole Polytechnique Fédérale de Lausanne (EPFL), ANR-19-CE30-0005,GRANUL,GRANULation de l'espace des phases dans les plasmas de fusion(2019), European Project: 101052200,Implementation of activities described in the Roadmap to Fusion during Horizon Europe through a joint programme of the members of the EUROfusion consortium,EUROfusion, and European Project: 824158,H2020-EU.1.4. - EXCELLENT SCIENCE - Research Infrastructures ,EoCoE-II(2019)
Subjects: kelvin-helmholtz instability, fusion, Nuclear and High Energy Physics, fluctuations, turbulence, E x B shear, discharges, shear, Condensed Matter Physics, gyrokinetic, zonal flows, [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], confinement, simulations, radial electric-field, transport barrier, physics, plasma
Abstract: Two ways for producing a transport barrier through strong shear of the E × B poloidal flow have been investigated using GYSELA gyrokinetic simulations in a flux-driven regime. The first one uses an external poloidal momentum (i.e. vorticity) source that locally polarizes the plasma, and the second one enforces a locally steep density profile that also stabilizes the ion temperature gradient (ITG) instability modes linearly. Both cases show a very low local turbulent heat diffusivity coefficient χ T turb and a slight increase in core pressure when a threshold of ω E × B ≈ γ ¯ lin (respectively the E × B shear rate and average linear growth rate of ITG) is reached, validating previous numerical results. This pressure increase and χ T turb quench are the signs of a transport barrier formation. This behaviour is the result of a reduced turbulence intensity which strongly correlates with the shearing of turbulent structures as evidenced by a reduction of the auto-correlation length of potential fluctuations as well as an intensity reduction of the k θ spectrum. Moreover, a small shift towards smaller poloidal wavenumber is observed in the vorticity source region which could be linked to a tilt of the turbulent structures in the poloidal direction.
Published: 2022
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8. 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
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9. $\mathbf{E}\times \mathbf{B}$ staircases and barrier permeability in magnetised plasmas

Author: G. Hornung, G. Dif-Pradalier, F. Clairet, Y. Sarazin, R. Sabot, P. Hennequin, G. Verdoolaege
Published: 2017
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10. Edge localized mode physics and operational aspects in tokamaks

Author: H. R. Wilson, O. Tudisco, A. Hermann, G. Saibene, S. Saarelma, M. Becoulet, M. Gryaznevich, S. E. Sharapov, V.V. Parail, A. Kirk, R.J. Buttery, A. C. C. Sips, R. Sartori, P. Beyer, P. Gohil, N. Asakura, E. Giovannozzi, L. L. Lao, Contributors to Jet-Efda Workprogramme, R. A. Moyer, Yutaka Kamada, M. Valovic, J. Lonnroth, Y. Sarazin, Anthony Leonard, P. Lomas, G. T. A. Huysmans, E. Joffrin, Peter Lang, W. Suttrop, J. Stober, F. Crisanti, P. B. Snyder, K-D. Zastrow, P. Thomas, S. Gerasimov, P. de Vries, G. Matthews, G. Counsell, H. R. Koslowski, A. Grosman, A. V. Chankin, Ph. Ghendrih, J.-M. Ané, T. E. Evans, P. Monier-Garbet, A. Loarte, F. Rimini, T. Eich, C. Perez, X. Garbet, L. D. Horton, Naoyuki Oyama, T. Hatae, and X. Litaudon
Subjects: Physics, Safety factor, Tokamak, Divertor, Magnetic confinement fusion, Mechanics, Collisionality, Condensed Matter Physics, law.invention, Nuclear physics, Pedestal, Nuclear Energy and Engineering, Physics::Plasma Physics, law, Magnetohydrodynamics, Edge-localized mode
Abstract: Recent progress in experimental and theoretical studies of edge localized mode (ELM) physics is reviewed for the reactor relevant plasma regimes, namely the high confinement regimes, that is, H-modes and advanced scenarios.Theoretical approaches to ELM physics, from a linear ideal magnetohydrodynamic (MHD) stability analysis to non-linear transport models with ELMs are discussed with respect to experimental observations, in particular the fast collapse of pedestal pressure profiles, magnetic measurements and scrape-off layer transport during ELMs.High confinement regimes with different types of ELMs are addressed in this paper in the context of development of operational scenarios for ITER. The key parameters that have been identified at present to reduce the energy losses in Type I ELMs are operation at high density, high edge magnetic shear and high triangularity. However, according to the present experimental scaling for the energy losses in Type I ELMs, the extrapolation of such regimes for ITER leads to unacceptably large heat loads on the divertor target plates exceeding the material limits. High confinement H-mode scenarios at high triangularity and high density with small ELMs (Type II), mixed regimes (Type II and Type I) and combined advanced regimes at high βp are discussed for present-day tokamaks. The optimum combination of high confinement and small MHD activity at the edge in Type II ELM scenarios is of interest to ITER. However, to date, these regimes have been achieved in a rather narrow operational window and far from ITER parameters in terms of collisionality, edge safety factor and βp.The compatibility of the alternative internal transport barrier (ITB) scenario with edge pedestal formation and ELMs is also addressed. Edge physics issues related to the possible combination of small benign ELMs (Type III, Type II ELMs, quiescent double barrier) and high performance ITBs are discussed for present-day experiments (JET, JT-60U, DIII-D) in terms of their relevance for ITER. Successful plasma edge control, at high triangularity (~0.5) and high density (~0.7nGR), in ITB scenarios in JET is reported.Active control of ELMs by edge current, pellet injection, impurities and external magnetic perturbations creating an ergodic zone localized at the separatrix are discussed for present-day experiments and from the perspective of future reactors.
Published: 2003
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11. Heating, current drive and energetic particle studies on JET in preparation of ITER operation

Author: T. Hellsten, F. Nguyen, Ph. Lamalle, D. A. D'Ippolito, J. Pamela, Y. Sarazin, A. Cardinali, I. Monakhov, F. Crisanti, J.R. Myra, A. A. Tuccillo, Vasily Kiptily, D. Van Eester, Olivier Sauter, R. Budny, M. J. Mantsinen, A. Ekedahl, X. Litaudon, J. deGrassie, D. A. Hartmann, M.-L. Mayoral, E. Joffrin, C. Ingesson, Jet-Efda Contributors, Jukka Heikkinen, D. Mazon, F. Durodié, J.-M. Noterdaeme, R. Cesario, S. E. Sharapov, C. Castaldo, T. T. C. Jones, Fernando Meo, J. Mailloux, V. Pericoli, Yu. Petrov, and A. Figueiredo
Subjects: Nuclear and High Energy Physics, Jet (fluid), Materials science, Tokamak, Toroid, fusion reactors, Magnetic confinement fusion, Plasma, Fusion power, Condensed Matter Physics, Charged particle, law.invention, fusion energy, JET, Physics::Plasma Physics, law, ITER, Plasma shaping, internal transport barriers, Atomic physics, plasma
Abstract: This paper summarizes the recent work on JET in the three areas of heating, current drive and energetic particles. The achievements have extended the possibilities of JET, have a direct connection to ITER operation and provide new and interesting physics. Toroidal rotation profiles of plasmas heated far off axis with little or no refuelling or momentum input are hollow with only small differences on whether the power deposition is located on the low field side or on the high field side. With LH current drive the magnetic shear was varied from slightly positive to negative. The improved coupling (through the use of plasma shaping and CD4) allowed up to 3.4 MW of PLH in internal transport barrier (ITB) plasmas with more than 15 MW of combined NBI and ICRF heating. The q-profile with negative magnetic shear and the ITB could be maintained for the duration of the high heating pulse (8 s). Fast ions have been produced in JET with ICRF to simulate alpha particles: by using third harmonic 4He heating, beam injected 4He at 120 kV were accelerated to energies above 2 MeV, taking advantage of the unique capability of JET to use NBI with 4He and to confine MeV class ions. ICRF heating was used to replicate the dynamics of alpha heating and the control of an equivalent Q = 10 'burn' was simulated.
Published: 2003
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12. Comprehensive comparisons of geodesic acoustic mode characteristics and dynamics between Tore Supra experiments and gyrokinetic simulations

Author: A. Storelli, L. Vermare, P. Hennequin, Ö. D. Gürcan, G. Dif-Pradalier, Y. Sarazin, X. Garbet, T. Görler, Rameswar Singh, P. Morel, V. Grandgirard, P. Ghendrih
Published: 2015
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13. Towards fully non-inductive current drive operation in JET

Author: X Litaudon, F Crisanti, B Alper, J F Artaud, Yu F Baranov, E Barbato, V Basiuk, A Bécoulet, M Bécoulet, C Castaldo, C D Challis, G D Conway, R Dux, L G Eriksson, B Esposito, C Fourment, D Frigione, X Garbet, C Giroud, N C Hawkes, P Hennequin, G T A Huysmans, F Imbeaux, E Joffrin, P J Lomas, Ph Lotte, P Maget, M Mantsinen, J Mailloux, D Mazon, F Milani, D Moreau, V Parail, E Pohn, F G Rimini, Y Sarazin, G Tresset, K D Zastrow, M Zerbini, and contributors to the EFDA-JET Workprogramme
Subjects: Physics, Resistive touchscreen, Jet (fluid), Safety factor, Tokamak, Magnetic confinement fusion, Mechanics, Condensed Matter Physics, Bootstrap current, law.invention, Nuclear Energy and Engineering, law, Beta (plasma physics), Current (fluid), Atomic physics
Abstract: Quasi-steady operation has been achieved at JET in the high-confinement regime with internal transport barriers (ITBs). The ITB has been maintained up to 11 s. This duration, much larger than the energy confinement time, is already approaching a current resistive time. The high-performance phase is limited only by plant constraints. The radial profiles of the thermal electron and ion pressures have steep gradients typically at mid-plasma radius. A large fraction of non-inductive current (above 80%) is sustained throughout the high-performance phase with a poloidal beta exceeding unity. The safety factor profile plays an important role in sustaining the ITB characteristics. In this regime where the self-generated bootstrap current (up to 1.0 MA) represents 50% of the total current, the resistive evolution of the non-monotonic q-profile is slowed down by using off-axis lower-hybrid current drive.
Published: 2002
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14. Progress in internal transport barrier plasmas with lower hybrid current drive and heating in JET (Joint European Torus)

Author: F. Imbeaux, J. Mailloux, T. J. J. Tala, C. D. Challis, R. Prentice, A. Ekedahl, A. A. Tuccillo, Y. Baranov, R. Cesario, X. Litaudon, P. de Vries, G. M. D. Hogeweij, K. Erents, F. Crisanti, V. Pericoli, Y. Sarazin, Efda-Jet workprogramme, P J Lomas, C. Gowers, G. F. Matthews, E. Joffrin, A. Becoulet, A. Cardinali, Garrard Conway, B. C. Stratton, N. Hawkes, B. Alper, M. de Baar, D. Mazon, C. Castaldo, F. Rimini, and K-D. Zastrow
Subjects: plasma hybrid waves, Physics, plasma density, Electron density, Toroid, Safety factor, plasma diagnostics, plasma simulation, Joint European Torus, fusion reactor safety, plasma radiofrequency heating, Plasma, Condensed Matter Physics, plasma toroidal confinement, Electromagnetic radiation, plasma transport processes, Neutral beam injection, plasma beam injection heating, Physics::Plasma Physics, Plasma diagnostics, electron density, Atomic physics, plasma temperature, plasma
Abstract: In optimized shear plasmas in the Joint European Torus [P. H. Rebut and B. E. Keen, Fusion Technol. 11, 13 (1987)], safety factor (q) profiles with negative magnetic shear are produced by applying lower hybrid (LH) waves during the plasma current ramp-up phase. These plasmas produce a barrier to the electron energy transport. The radius at which the barrier is located increases with the LH wave power. When heated with high power from ion cyclotron resonance heating and neutral beam injection, they can additionally produce transient internal transport barriers (ITBs) seen on the ion temperature, electron density, and toroidal rotation velocity profiles. Due to recent improvements in coupling, q profile control with LH current drive in ITB plasmas with strong combined heating can be explored. These new experiments have led to ITBs sustained for several seconds by the LH wave. Simulations show that the current driven by the LH waves peaks at the ITB location, indicating that it can act in the region of low magnetic shear.
Published: 2002
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15. ELMs behaviour and edge plasma stability in JET

Author: M Becoulet, V Parail, G Huysmans, S Sharapov, P J Lomas, G Saibene, R Sartori, A Loarte, G F Matthews, W Suttrop, J Stober, A Kallenbach, E Joffrin, Y Sarazin, X Litaudon, A Becoulet, Ph Ghendrih, and the contributors to the JET-EFDA Workprogramme
Subjects: Physics, Jet (fluid), Tokamak, Magnetic confinement fusion, Plasma, Condensed Matter Physics, Ballooning, law.invention, Pedestal, Nuclear Energy and Engineering, law, Atomic physics, Magnetohydrodynamics, Plasma stability
Abstract: Recent experimental results and plasma edge stability studies of ELMs are presented for both H-mode and optimized shear (OS) plasmas in JET. High triangularity (δ~0.5) ELMy \mbox{H-mode} experiments in JET achieved simultaneously high confinement (HIPB(y,2) = 1) and high density (~0.9 nGR). At high pedestal density (~1.1nGR), an anomalous decrease of type I ELMs frequency and energy losses per ELM was observed. A specific for high triangularity and high density (δ~0.5 and ne~1.1nGR) MHD activity with broad-band frequency spectrum (
Published: 2002
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16. 2D and 3D boundary turbulence studies

Author: Xavier Garbet, P. Beyer, S. Benkadda, Philippe Ghendrih, and Y Sarazin
Subjects: Physics, Tokamak, Condensed matter physics, K-epsilon turbulence model, Turbulence, Mechanics, K-omega turbulence model, Tore Supra, Condensed Matter Physics, Thermal diffusivity, law.invention, Magnetic field, Nuclear Energy and Engineering, Physics::Plasma Physics, law, Electric field
Abstract: Pressure driven curvature instabilities at the boundary of a tokamak plasma are studied. First, three-dimensional turbulence simulations are presented including the case where magnetic field lines are stochastic. Three main features are observed: (i) the level of pressure fluctuations decreases in the ergodic layer. (ii) This is essentially due to a suppression of large-scale structures. (iii) The turbulent heat diffusivity does not decrease in the stochastic layer due to an increase of electric field fluctuations. These observations are in agreement with turbulence measurements on Tore Supra. Second, particle flux driven turbulence in the scrape-off layer (SOL) is studied using a two-dimensional code. The transverse transport is found to be ballistic and intermittent. Bursts propagate outwards with a radial velocity of the order of one tenth of the parallel velocity. Test particles undergo outward and inward trajectories. The order of magnitude of the e-folding SOL length is in agreement with experimental data.
Published: 1999
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17. Plasma turbulence simulations with X-points using the flux-coordinate independent approach

Author: Y. Sarazin, F. Hariri, P. Hill, and M. Ottaviani
Subjects: Physics, Work (thermodynamics), Toroid, Turbulence, Resolution (electron density), Flux, FOS: Physical sciences, Condensed Matter Physics, Physics - Plasma Physics, Computational physics, Magnetic field, Plasma Physics (physics.plasm-ph), Nonlinear system, Nuclear Energy and Engineering, Physics::Plasma Physics, Range (statistics), X-points, Field-aligned coordinates
Abstract: In this work, the flux-coordinate independent (FCI) approach to plasma turbulence simulations is formulated for the case of generic, static magnetic fields, including those possessing stochastic field lines. It is then demonstrated that FCI is applicable to nonlinear turbulent problems with and without X-point geometry. In particular, by means of simulations with the FENICIA code, it is shown that the standard features of ion temperature gradient (ITG) modes are recovered with reduced toroidal resolution. Finally, the impact of ITG turbulent transport on the temperature profile is studied under the influence of a static island, with ITER-like parameters. Results show the wide range of applicability of the method.
Published: 2014
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18. Self-organized criticality in particle transport governed by ionization

Author: Y Sarazin
Subjects: Nuclear and High Energy Physics, Nuclear Energy and Engineering, General Materials Science
Published: 1997
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19. EFD-C(13)03/07 L to H Mode Transition: On the Role of Zeff

Author: C. Bourdelle, C.F. Maggi, L. Chôné, P. Beyer, G. Fuhr, X. Garbet, A. Loarte, F. Millitello, A. Monnier, M. Romanelli, S. Saarelma, Y. Sarazin, and JET EFDA contributors
Abstract: In this paper, the nature of the primary instability present in the pedestal forming region prior to the transition into H mode will be analyzed by a gyrokinetic code GENE on JET ITER Like Wall (ILW) profiles. It will be shown that the primary instability is of resistive nature, and can therefore be stabilized by increased temperature, hence power. Its growth rate reaches a minimum for a temperature of the order of the experimentally measured temperature at the transition. Its resistive nature leads to a reduced growth rate as the effective charge Zeff is increased. This dependence will be shown to be in qualitative agreement with recent experimental observations. The impact of the ILW shows a L to H mode power threshold reduced by ~ 40% in ILW with respect to similar experiments in C wall. The experiments were carried out with slow power ramps and matched plasma shapes, divertor configurations and Ip/BT pairs. In ASDEX Upgrade as well, a reduction of the power threshold, linked to the metalization of the machine, has been observed when compared to the ITPA-2008 scaling law. A common feature of JET ILWand ASDEX Upgrade is an observed significant reduction of the Zeff when switching from C walls to metallic ones.
Published: 2013
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20. EFD-P(13)34 L to H Mode Transition: On the Role of Zeff

Author: C. Bourdelle, C.F. Maggi, L. Chôné, P. Beyer, J. Citrin, N. Fedorczak, X. Garbet, A. Loarte, F. Millitello, M. Romanelli, Y. Sarazin, and JET EFDA contributors
Abstract: In this paper, the nature of the primary instability present in the pedestal forming region prior to the transition into H mode is analyzed using a gyrokinetic code on JET-ILW profiles. The linear analysis shows that the primary instability is of resistive nature, and can therefore be stabilized by increased temperature, hence power. Its growth rate reaches a minimum for a temperature corresponding to the magnitude of the experimentally measured temperature at the L-H transition. The minimum of the growth rate is shifted towards lower temperature for lower effective charge Zeff. This dependence is shown to be in qualitative agreement with recent and past experimental observations of reduced Zeff associated with lower L-H power thresholds.
Published: 2013
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21. Physics of Intrinsic Rotation in Flux-Driven ITG Turbulence

Author: S Ku, P H Dimond, G Dif-Pradalier, J M Kwon, Y Sarazin, T S Hahm, X Garbet, C S Chang, G Latu, E S Yoon, Ph Ghendrih, S Yi, A Strugarek, and W Solomon
Published: 2012
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22. Predictions on heat transport and plasma rotation from global gyrokinetic simulations

Author: Choong-Seock Chang, S. Allfrey, Ph. Ghendrih, Guillaume Latu, Antoine Strugarek, Seung-Hoe Ku, T. M. Tran, J. Abiteboul, Ben F. McMillan, L. Villard, Paolo Angelino, Guilhem Dif-Pradalier, V. Grandgirard, Alberto Bottino, S. Jolliet, Patrick Diamond, Xavier Garbet, and Y. Sarazin
Subjects: Nuclear and High Energy Physics, Tokamak, Transport coefficient, Fluids & Plasmas, IAEA, Collisionality, Rotation, Atomic, law.invention, Particle and Plasma Physics, law, Physics::Plasma Physics, Models, Driven, Nuclear, Statistical physics, Scaling, nuclear fusion, Physics, Cauchy stress tensor, Turbulence, Code, Toroidal Rotation, turbulence, Molecular, Mechanics, Radius, Condensed Matter Physics, Jet, HPC, transport, Zonal Flows, Neoclassical Transport, Tokamaks
Abstract: Flux-driven global gyrokinetic codes are now mature enough to make predictions in terms of turbulence and transport in tokamak plasmas. Some of the recent breakthroughs of three such codes, namely GYSELA, ORB5 and XGC1, are reported and compared wherever appropriate. In all three codes, turbulent transport appears to be mediated by avalanche-like events, for a broad range of ρ* = ρi/a values, ratio of the gyro-radius over the minor radius. Still, the radial correlation length scales with ρi, leading to the gyro-Bohm scaling of the effective transport coefficient below ρ* ≈ 1/300. The possible explanation could be due to the fact that avalanches remain meso-scale due to the interaction with zonal flows, whose characteristic radial wavelength appears to be almost independent of the system size. As a result of the radial corrugation of the turbulence driven zonal and mean flows, the shear of the radial electric field can be significantly underestimated if poloidal rotation is assumed to be governed by the neoclassical theory, especially at low collisionality. Indeed, the turbulence contribution to the poloidal rotation increases when collisionality decreases. Finally, the numerical verification of toroidal momentum balance shows that both neoclassical and turbulent contributions to the Reynolds' stress tensor play the dominant role. The phase space analysis further reveals that barely passing supra-thermal particles mostly contribute to the toroidal flow generation, consistently with quasi-linear predictions.
Published: 2011
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23. Contribution of Tore Supra in preparation of ITER

Author: B. Saoutic, J. Abiteboul, L. Allegretti, S. Allfrey, J.M. Ané, T. Aniel, A. Argouarch, J.F. Artaud, M.H. Aumenier, S. Balme, V. Basiuk, O. Baulaigue, P. Bayetti, A. Bécoulet, M. Bécoulet, M.S. Benkadda, F. Benoit, G. Berger-by, J.M. Bernard, B. Bertrand, P. Beyer, A. Bigand, J. Blum, D. Boilson, G. Bonhomme, H. Bottollier-Curtet, C. Bouchand, F. Bouquey, C. Bourdelle, S. Bourmaud, C. Brault, S. Brémond, C. Brosset, J. Bucalossi, Y. Buravand, P. Cara, V. Catherine-Dumont, A. Casati, M. Chantant, M. Chatelier, G. Chevet, D. Ciazynski, G. Ciraolo, F. Clairet, M. Coatanea-Gouachet, L. Colas, L. Commin, E. Corbel, Y. Corre, X. Courtois, R. Dachicourt, M. Dapena Febrer, M. Davi Joanny, R. Daviot, H. De Esch, J. Decker, P. Decool, P. Delaporte, E. Delchambre, E. Delmas, L. Delpech, C. Desgranges, P. Devynck, T. Dittmar, L. Doceul, D. Douai, H. Dougnac, J.L. Duchateau, B. Dugué, N. Dumas, R. Dumont, A. Durocher, F.X. Duthoit, A. Ekedahl, D. Elbeze, M. El Khaldi, F. Escourbiac, F. Faisse, G. Falchetto, M. Farge, J.L. Farjon, M. Faury, N. Fedorczak, C. Fenzi-Bonizec, M. Firdaouss, Y. Frauel, X. Garbet, J. Garcia, J.L. Gardarein, L. Gargiulo, P. Garibaldi, E. Gauthier, O. Gaye, A. Géraud, M. Geynet, P. Ghendrih, I. Giacalone, S. Gibert, C. Gil, G. Giruzzi, M. Goniche, V. Grandgirard, C. Grisolia, G. Gros, A. Grosman, R. Guigon, D. Guilhem, B. Guillerminet, R. Guirlet, J. Gunn, O. Gurcan, S. Hacquin, J.C. Hatchressian, P. Hennequin, C. Hernandez, P. Hertout, S. Heuraux, J. Hillairet, G.T. Hoang, C. Honore, M. Houry, T. Hutter, P. Huynh, G. Huysmans, F. Imbeaux, E. Joffrin, J. Johner, L. Jourd'Heuil, Y.S. Katharria, D. Keller, S.H. Kim, M. Kocan, M. Kubic, B. Lacroix, V. Lamaison, G. Latu, Y. Lausenaz, C. Laviron, F. Leroux, L. Letellier, M. Lipa, X. Litaudon, T. Loarer, P. Lotte, S. Madeleine, P. Magaud, P. Maget, R. Magne, L. Manenc, Y. Marandet, G. Marbach, J.L. Maréchal, L. Marfisi, C. Martin, G. Martin, V. Martin, A. Martinez, J.P. Martins, R. Masset, D. Mazon, N. Mellet, L. Mercadier, A. Merle, D. Meshcheriakov, O. Meyer, L. Million, M. Missirlian, P. Mollard, V. Moncada, P. Monier-Garbet, D. Moreau, P. Moreau, L. Morini, M. Nannini, M. Naiim Habib, E. Nardon, H. Nehme, C. Nguyen, S. Nicollet, R. Nouilletas, T. Ohsako, M. Ottaviani, S. Pamela, H. Parrat, P. Pastor, A.L. Pecquet, B. Pégourié, Y. Peysson, I. Porchy, C. Portafaix, M. Preynas, M. Prou, J.M. Raharijaona, N. Ravenel, C. Reux, P. Reynaud, M. Richou, H. Roche, P. Roubin, R. Sabot, F. Saint-Laurent, S. Salasca, F. Samaille, A. Santagiustina, Y. Sarazin, A. Semerok, J. Schlosser, M. Schneider, M. Schubert, F. Schwander, J.L. Ségui, G. Selig, P. Sharma, J. Signoret, A. Simonin, S. Song, E. Sonnendruker, F. Sourbier, P. Spuig, P. Tamain, M. Tena, J.M. Theis, D. Thouvenin, A. Torre, J.M. Travère, E. Tsitrone, J.C. Vallet, E. Van Der Plas, A. Vatry, J.M. Verger, L. Vermare, F. Villecroze, D. Villegas, R. Volpe, K. Vulliez, J. Wagrez, T. Wauters, L. Zani, D. Zarzoso, X.L. Zou, Institut de Recherche sur la Fusion par confinement Magnétique (IRFM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Science et Ingénierie des Matériaux et Procédés (SIMaP), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS), Dept. Accelerateurs - XFEL, Laboratoire de l'Accélérateur Linéaire (LAL), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École polytechnique (X)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174) (FEMTO-ST), Université de Technologie de Belfort-Montbeliard (UTBM)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS), Institut universitaire des systèmes thermiques industriels (IUSTI), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Matériaux et Mécanique des Composants (EDF R&D MMC), EDF R&D (EDF R&D), EDF (EDF)-EDF (EDF), Association EURATOM-CEA (CEA/DSM/DRFC), Département de Recherche sur la Fusion Contrôlée (DRFC), Laboratoire d'Interaction Laser Matière (LILM), Département de Physico-Chimie (DPC), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, 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)-Sorbonne Université-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut Jean Lamour (IJL), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Ngee Ann Polytechnic, School of Engineering, Mechanical Engineering Division, ITER organization (ITER), CEA Cadarache, Centre de Thermique de Lyon (CETHIL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), CEA ISIS, 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), Institut de Chimie de Clermont-Ferrand (ICCF), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-SIGMA Clermont (SIGMA Clermont)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche en Sciences et Techniques de la Ville - FR 2488 (IRSTV), Université de Nantes (UN)-École Centrale de Nantes (ECN)-EC. ARCHIT. NANTES-Université d'Angers (UA)-Université de La Rochelle (ULR)-Centre National de la Recherche Scientifique (CNRS), Eau et Environnement (IFSTTAR/GERS/EE), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-PRES Université Nantes Angers Le Mans (UNAM), Physique des interactions ioniques et moléculaires (PIIM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Intégration des Systèmes et des Technologies (LIST), Institut des Sciences de l'Evolution de Montpellier (UMR ISEM), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Institut de recherche pour le développement [IRD] : UR226-Centre National de la Recherche Scientifique (CNRS), Centre of Molecular and Structural Biomedicine (CBME)/Institute of Biotechnology and Bioengineering (IBB), University of Algarve [Portugal], Laboratoire Lasers, Plasmas et Procédés photoniques (LP3), Centre d'Histoire 'Espaces et Cultures' (CHEC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP), École des hautes études en sciences sociales (EHESS), Centre hospitalier universitaire de Nantes (CHU Nantes), Centre de Recherche en Cancérologie Nantes-Angers (CRCNA), Centre Hospitalier Universitaire d'Angers (CHU Angers), PRES Université Nantes Angers Le Mans (UNAM)-PRES Université Nantes Angers Le Mans (UNAM)-Hôtel-Dieu de Nantes-Institut National de la Santé et de la Recherche Médicale (INSERM)-Hôpital Laennec-Centre National de la Recherche Scientifique (CNRS)-Faculté de Médecine d'Angers-Centre hospitalier universitaire de Nantes (CHU Nantes), Centre d'investigation clinique en cancérologie (CI2C), IFP Energies nouvelles (IFPEN), Matériaux, ingénierie et science [Villeurbanne] (MATEIS), Ecologie Systématique et Evolution (ESE), Centre National de la Recherche Scientifique (CNRS)-AgroParisTech-Université Paris-Sud - Paris 11 (UP11), Laboratoire d'Etude des Matériaux en Milieux Agressifs (LEMMA), Université de La Rochelle (ULR), CMCR des Massues, Croix rouge française, Laboratoire Procédés et Ingénierie en Mécanique et Matériaux (PIMM), Conservatoire National des Arts et Métiers [CNAM] (CNAM)-Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM), Laboratoire de Mécanique, Modélisation et Procédés Propres (M2P2), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Réserve Naturelle Nationale Baie St-Brieuc, Réserves Naturelles de France-Réserves Naturelles de France, Géoazur (GEOAZUR 6526), Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Direction des Jardins botaniques et zoologiques, Muséum national d'Histoire naturelle (MNHN), Department of Information Technology (INTEC), Ghent University [Belgium] (UGENT), Dipartimento di Ingegneria dell'Ambiente e per lo Sviluppo Sostenibile (DIASS), Dipartimento Ingn Ambiente & Sviluppo Soste, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2), Equipe Dynamique des Systemes Complexes, Université de Provence - Aix-Marseille 1, Technische Universität Braunschweig [Braunschweig], Laboratoire de physique des milieux ionisés et applications (LPMIA), Université Henri Poincaré - Nancy 1 (UHP)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche en Cancérologie de Lyon (UNICANCER/CRCL), Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre Léon Bérard [Lyon], Bureau de Recherches Géologiques et Minières (BRGM) (BRGM), Service de Chimie Physique (SCP), Laboratoire des Adaptations Physiologiques aux Activités Physiques (LAPHAP), Université de Poitiers, Institut d'Electronique du Solide et des Systèmes ( InESS ), Centre National de la Recherche Scientifique ( CNRS ), Institut de Recherche sur la Fusion par confinement Magnétique ( IRFM ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ), Science et Ingénierie des Matériaux et Procédés ( SIMaP ), Université Joseph Fourier - Grenoble 1 ( UJF ) -Institut polytechnique de Grenoble - Grenoble Institute of Technology ( Grenoble INP ) -Institut National Polytechnique de Grenoble ( INPG ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Grenoble Alpes ( UGA ), Laboratoire de l'Accélérateur Linéaire ( LAL ), Université Paris-Sud - Paris 11 ( UP11 ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Paris-Sud - Paris 11 ( UP11 ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Météorologie Dynamique (UMR 8539) ( LMD ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -École polytechnique ( X ) -École des Ponts ParisTech ( ENPC ) -Centre National de la Recherche Scientifique ( CNRS ) -Département des Géosciences - ENS Paris, École normale supérieure - Paris ( ENS Paris ) -École normale supérieure - Paris ( ENS Paris ), Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies ( FEMTO-ST ), Université de Technologie de Belfort-Montbeliard ( UTBM ) -Ecole Nationale Supérieure de Mécanique et des Microtechniques ( ENSMM ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Franche-Comté ( UFC ), Institut universitaire des systèmes thermiques industriels ( IUSTI ), Centre National de la Recherche Scientifique ( CNRS ) -Aix Marseille Université ( AMU ), EDF - R&D Department MMC and MAI, EDF R&D ( EDF R&D ), EDF ( EDF ) -EDF ( EDF ), Association EURATOM-CEA ( CEA/DSM/DRFC ), Département de Recherche sur la Fusion Contrôlée ( DRFC ), Laboratoire d'Interaction Laser Matière ( LILM ), Département de Physico-Chimie ( DPC ), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ), Laboratoire de Physique des Plasmas ( LPP ), Université Paris-Sud - Paris 11 ( UP11 ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Observatoire de Paris-École polytechnique ( X ) -Sorbonne Universités-PSL Research University ( PSL ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ), Institut Jean Lamour ( IJL ), Centre National de la Recherche Scientifique ( CNRS ) -Université de Lorraine ( UL ), Département de Physique Nucléaire (ex SPhN) ( DPHN ), Institut de Recherches sur les lois Fondamentales de l'Univers ( IRFU ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay, ITER [St. Paul-lez-Durance], ITER, Centre de Thermique de Lyon ( CETHIL ), Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon ( INSA Lyon ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire d'Electronique et des Technologies de l'Information ( CEA-LETI ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Grenoble Alpes [Saint Martin d'Hères], Institut de Chimie de Clermont-Ferrand ( ICCF ), Université Blaise Pascal - Clermont-Ferrand 2 ( UBP ) -Sigma CLERMONT ( Sigma CLERMONT ) -Centre National de la Recherche Scientifique ( CNRS ), Institut de Recherche en Sciences et Techniques de la Ville ( IRSTV ), Université d'Angers ( UA ) -Université de Nantes ( UN ) -École Centrale de Nantes ( ECN ) -Université de La Rochelle ( ULR ) -EC. ARCHIT. NANTES-Centre National de la Recherche Scientifique ( CNRS ), Eau et Environnement ( IFSTTAR/GERS/EE ), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux ( IFSTTAR ) -PRES Université Nantes Angers Le Mans ( UNAM ), Physique des interactions ioniques et moléculaires ( PIIM ), Aix Marseille Université ( AMU ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire d'Intégration des Systèmes et des Technologies ( LIST ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay, Institut des Sciences de l'Evolution de Montpellier ( ISEM ), Université de Montpellier ( UM ) -Institut de recherche pour le développement [IRD] : UR226-Centre National de la Recherche Scientifique ( CNRS ), Laboratoire Lasers, Plasmas et Procédés photoniques ( LP3 ), Centre d'Histoire 'Espaces et Cultures' ( CHEC ), Université Blaise Pascal - Clermont-Ferrand 2 ( UBP ), École des hautes études en sciences sociales ( EHESS ), Centre hospitalier universitaire de Nantes ( CHU Nantes ), Centre de Recherche en Cancérologie / Nantes - Angers ( CRCNA ), CHU Angers-Centre hospitalier universitaire de Nantes ( CHU Nantes ) -Hôtel-Dieu de Nantes-Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Hôpital Laennec-Centre National de la Recherche Scientifique ( CNRS ) -Faculté de Médecine d'Angers, Centre d'investigation clinique en cancérologie ( CI2C ), IFP Energies nouvelles ( IFPEN ), Matériaux, ingénierie et science [Villeurbanne] ( MATEIS ), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique ( CNRS ) -Institut National des Sciences Appliquées de Lyon ( INSA Lyon ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ), Ecologie Systématique et Evolution ( ESE ), Université Paris-Sud - Paris 11 ( UP11 ) -AgroParisTech-Centre National de la Recherche Scientifique ( CNRS ), Laboratoire d'Etude des Matériaux en Milieux Agressifs ( LEMMA ), Université de La Rochelle ( ULR ), Institut des Sciences Chimiques de Rennes ( ISCR ), Université de Rennes 1 ( UR1 ), Université de Rennes ( UNIV-RENNES ) -Université de Rennes ( UNIV-RENNES ) -Ecole Nationale Supérieure de Chimie de Rennes-Institut National des Sciences Appliquées ( INSA ) -Centre National de la Recherche Scientifique ( CNRS ), Croix-rouge française, Procédés et Ingénierie en Mécanique et Matériaux [Paris] ( PIMM ), Centre National de la Recherche Scientifique ( CNRS ) -Conservatoire National des Arts et Métiers [CNAM] ( CNAM ), Institut de Microélectronique, Electromagnétisme et Photonique - Laboratoire d'Hyperfréquences et Caractérisation ( IMEP-LAHC ), Centre National de la Recherche Scientifique ( CNRS ) -Université Savoie Mont Blanc ( USMB [Université de Savoie] [Université de Chambéry] ) -Institut National Polytechnique de Grenoble ( INPG ) -Université Joseph Fourier - Grenoble 1 ( UJF ) -Institut polytechnique de Grenoble - Grenoble Institute of Technology ( Grenoble INP ) -Université Grenoble Alpes ( UGA ), Laboratoire de Mécanique, Modélisation et Procédés Propres ( M2P2 ), Aix Marseille Université ( AMU ) -Ecole Centrale de Marseille ( ECM ) -Centre National de la Recherche Scientifique ( CNRS ), Géoazur ( GEOAZUR ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Université Nice Sophia Antipolis ( UNS ), Université Côte d'Azur ( UCA ) -Université Côte d'Azur ( UCA ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de la Côte d'Azur, Université Côte d'Azur ( UCA ) -Centre National de la Recherche Scientifique ( CNRS ), Réserve de la Haute Touche, Muséum National d'Histoire Naturelle ( MNHN ), Department of Information Technology ( INTEC ), Ghent University [Belgium] ( UGENT ), Dipartimento di Ingegneria dell'Ambiente e per lo Sviluppo Sostenibile ( DIASS ), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier ( ICGM ICMMM ), Université Montpellier 1 ( UM1 ) -Université Montpellier 2 - Sciences et Techniques ( UM2 ) -Ecole Nationale Supérieure de Chimie de Montpellier ( ENSCM ) -Université de Montpellier ( UM ) -Centre National de la Recherche Scientifique ( CNRS ), Physique des milieux ionisés et applications ( LPMIA ), Université Henri Poincaré - Nancy 1 ( UHP ) -Centre National de la Recherche Scientifique ( CNRS ), Centre de Recherche en Cancérologie de Lyon ( CRCL ), Université de Lyon-Université de Lyon-Centre Léon Bérard [Lyon]-Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ), Bureau de Recherches Géologiques et Minières (BRGM) ( BRGM ), Catalyse par les métaux, Institut de Chimie des Milieux et Matériaux de Poitiers ( IC2MP ), Université de Poitiers-Centre National de la Recherche Scientifique ( CNRS ) -Université de Poitiers-Centre National de la Recherche Scientifique ( CNRS ), Service de Chimie Physique ( SCP ), Laboratoire des Adaptations Physiologiques aux Activités Physiques ( LAPHAP ), Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Centre Léon Bérard [Lyon]-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut National Polytechnique de Grenoble (INPG)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Université d'Angers (UA)-Université de Nantes (UN)-École Centrale de Nantes (ECN)-Université de La Rochelle (ULR)-EC. ARCHIT. NANTES-Centre National de la Recherche Scientifique (CNRS), École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut de recherche pour le développement [IRD] : UR226, Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Nice Sophia Antipolis (... - 2019) (UNS)
Subjects: Physics, [PHYS]Physics [physics], Nuclear and High Energy Physics, [ PHYS ] Physics [physics], Plasma parameters, Ripple, Plasma, Tore Supra, Collisionality, Condensed Matter Physics, 7. Clean energy, 01 natural sciences, 010305 fluids & plasmas, Computational physics, symbols.namesake, Nuclear magnetic resonance, Physics::Plasma Physics, 0103 physical sciences, symbols, Langmuir probe, Electron temperature, 010306 general physics, Power density
Abstract: International audience; Tore Supra routinely addresses the physics and technology of very long-duration plasma discharges, thus bringing precious information on critical issues of long pulse operation of ITER. A new ITER relevant lower hybrid current drive (LHCD) launcher has allowed coupling to the plasma a power level of 2.7 MW for 78 s, corresponding to a power density close to the design value foreseen for an ITER LHCD system. In accordance with the expectations, long distance (10 cm) power coupling has been obtained. Successive stationary states of the plasma current pro le have been controlled in real-time featuring (i) control of sawteeth with varying plasma parameters, (ii) obtaining and sustaining a `hot core' plasma regime, (iii) recovery from a voluntarily triggered deleterious magnetohydrodynamic regime. The scrape-off layer (SOL) parameters and power deposition have been documented during L-mode ramp-up phase, a crucial point for ITER before the X-point formation. Disruption mitigation studies have been conducted with massive gas injection, evidencing the difference between He and Ar and the possible role of the q = 2 surface in limiting the gas penetration. ICRF assisted wall conditioning in the presence of magnetic eld has been investigated, culminating in the demonstration that this conditioning scheme allows one to recover normal operation after disruptions. The effect of the magnetic eld ripple on the intrinsic plasma rotation has been studied, showing the competition between turbulent transport processes and ripple toroidal friction. During dedicated dimensionless experiments, the effect of varying the collisionality on turbulence wavenumber spectra has been documented, giving new insight into the turbulence mechanism. Turbulence measurements have also allowed quantitatively comparing experimental results with predictions by 5D gyrokinetic codes: numerical results simultaneously match the magnitude of effective heat diffusivity, rms values of density uctuations and wavenumber spectra. A clear correlation between electron temperature gradient and impurity transport in the very core of the plasma has been observed, strongly suggesting the existence of a threshold above which transport is dominated by turbulent electron modes. Dynamics of edge turbulent uctuations has been studied by correlating data from fast imaging cameras and Langmuir probes, yielding a coherent picture of transport processes involved in the SOL.
Published: 2011
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24. Transition to supersonic flows and fronts in the edge plasma, Joint Varenna-Laussane International Workshop Villa Monastero, Varenna

Author: Ghendrih, Philippe, K., Bodi, Bufferand, Hugo, G., Chiavassa, G., Ciraolo, Fedorczak, Nicolas, L., Isoardi, A., Paredes, Y., Sarazin, E., SERRE, F., Schwander, Tamain, Patrick, Laboratoire de Mécanique, Modélisation et Procédés Propres (M2P2), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Constant, Eddy, and Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU)
Subjects: [PHYS.MECA.MEFL] Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], ComputingMilieux_MISCELLANEOUS
Abstract: International audience; no abstract
Published: 2010

25. Parallel flow shear instability in the tokamak edge

Author: F., Schwander, G., Chiavassa, G., Ciraolo, L., Isoardi, E., SERRE, Ghendrih, Philippe, Y., Sarazin, Laboratoire de Mécanique, Modélisation et Procédés Propres (M2P2), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), Constant, Eddy, and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS.MECA.MEFL] Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], ComputingMilieux_MISCELLANEOUS
Abstract: International audience; no abstract
Published: 2010

26. 2D Modelling SOL-edge momentum exchange, 19th PSI Conference (Plasma Surface Interactions)

Author: Bufferand, Hugo, G., Ciraolo, G., Chiavassa, L., Isoardi, F., Schwander, E., SERRE, Fedorczak, Nicolas, Ghendrih, Philippe, J., Gunn, Y., Sarazin, Tamain, Patrick, Laboratoire de Mécanique, Modélisation et Procédés Propres (M2P2), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), Constant, Eddy, and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS.MECA.MEFL] Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], ComputingMilieux_MISCELLANEOUS
Abstract: International audience; no abstract
Published: 2010

27. Parallel expansion of a density burst, 19th PSI Conference (Plasma Surface Interactions)

Author: G., Chiavassa, Ghendrih, Philippe, G., Ciraolo, L., Isoardi, F., Schwander, E., SERRE, Y., Sarazin, Tamain, Patrick, H., Guillard, Laboratoire de Mécanique, Modélisation et Procédés Propres (M2P2), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), Constant, Eddy, and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS.MECA.MEFL] Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], ComputingMilieux_MISCELLANEOUS
Abstract: International audience; no abstract
Published: 2010

28. Measurements and Modeling of Turbulent Transport in the Tore Supra Tokamak

Author: X. Garbet, J. Abiteboul, S. Benkadda, C. Bourdelle, A. Casati, F. Clairet, N. Dubuit, G. Falchetto, C. Fenzi, S. Futatani, V. Grandgirard, R. Guirlet, Ö. D. Gürcan, P. Hennequin, S. Heuraux, G. T. Hoang, C. Honoré, R. Sabot, Y. Sarazin, J. L. Segui, A. Smolyakov, E. Trier, L. Vermare, D. Villegas, A. Sen, S. Sharma, P. N. Guzdar, 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, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)
Subjects: Physics, Tokamak, Toroid, Turbulence, 020206 networking & telecommunications, 02 engineering and technology, Mechanics, Tore Supra, Instability, law.invention, Physics::Fluid Dynamics, Nuclear physics, symbols.namesake, [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], Physics::Plasma Physics, law, 0202 electrical engineering, electronic engineering, information engineering, symbols, Wavenumber, 020201 artificial intelligence & image processing, Reflectometry, Doppler effect
Abstract: International audience; This paper presents an overview of recent advances in modeling and measurements of turbulence in Tore Supra plasmas. Spatio‐temporal properties of turbulence are discussed in relation with transport models. An explanation is proposed for the k−3 decay of wave number spectra, which are observed by using both coherent laser scattering and Doppler reflectometry. Also the interplay between turbulence and flows has been investigated. It is shown that toroidal rotation results from a competition between neoclassical and turbulence flow generation. Finally a new method has been proposed to determine the transport coefficients of impurities. These coefficients are usually well above the neoclassical prediction.
Published: 2010
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29. 2D Modelling of electron and ion temperature in the plasma edge and SOL

Author: L., Isoardi, G., Chiavassa, G., Ciraolo, F., Schwander, E., SERRE, S., VIAZZO, Fedorczak, Nicolas, Ghendrih, Philippe, J., Gunn, Y., Sarazin, Tamain, Patrick, Constant, Eddy, 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.MECA.MEFL] Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], ComputingMilieux_MISCELLANEOUS
Abstract: International audience; no abstract
Published: 2010

30. Dynamics of Edge Localized Modes

Author: Sadruddin Benkadda, Y. Sarazin, G. Fuhr-Chaudier, X. Garbet, P. Ghendrih, and P. Beyer
Subjects: Materials science, Dynamics (mechanics), Edge (geometry), Molecular physics
Published: 2009
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31. Stability properties of parallel flows at the transition between plasma core and scrape‐off layer

Author: F. Schwander, Ph. Ghendrih, Y. Sarazin, G. Chiavassa, G. Ciraolo, P. Haldenwang, L. Isoardi, E. Serre, Olivier Sauter, Xavier Garbet, Elio Sindoni, Institut de Recherche sur la Fusion par confinement Magnétique (IRFM), 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), Olivier Sauter , Xavier Garbet and Elio Sindoni, and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, Computation, Symmetric equilibrium, 020206 networking & telecommunications, 02 engineering and technology, Plasma, Mechanics, Instability, Stability (probability), [SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph], Momentum, Core (optical fiber), Classical mechanics, Numerical modeling, 0202 electrical engineering, electronic engineering, information engineering, Limiter, Flow instabilities, 020201 artificial intelligence & image processing, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], Plasma flows, Toroidal plasma confinement
Abstract: ISBN: 978-0-7354-0600-1; International audience; The Kelvin‐Helmholtz system is investigated numerically at the transition between the scrape‐off layer and the core of a limiter plasma in a simplified fluid model. The fundamental features of the parallel Kelvin‐Helmholtz instability are discussed in a simplified configuration, and a local instability parameter involving the parallel flow and density gradients is exhibited. Results of three‐dimensional computations of toroidally symmetric equilibrium solutions of the model are then presented, and the possible destabilization of Kelvin‐Helmholtz modes is briefly discussed. It is observed that for the stationary solutions found, the local radial gradients of the density and parallel momentum are such that the instability criterion is not satisfied.
Published: 2008
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32. A minimal collision operator for implementing neoclassical transport in gyrokinetic simulations

Author: X. Garbet, G. Dif-Pradalier, C. Nguyen, P. Angelino, Y. Sarazin, V. Grandgirard, P. Ghendrih, A. Samain, Olivier Sauter, Xavier Garbet, and Elio Sindoni
Subjects: Physics, Microwave amplifiers, Physics::Plasma Physics, Gyrokinetics, Fokker–Planck equation, Statistical physics, Thermal diffusivity, Collision, Collision operator
Abstract: This paper presents a class of collision operators, which reproduce neoclassical transport and comply with the constraints of a full‐f global gyrokinetic code. The assessment of these operators is based on a variational entropy method, which allows a fast calculation of the neoclassical diffusivity and poloidal velocity.
Published: 2008
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33. Gyrokinetic simulations of neoclassical transport using a minimal collision operator

Author: G. Dif-Pradalier, V. Grandgirard, Y. Sarazin, X. Garbet, Ph. Ghendrih, P. Angelino, Olivier Sauter, Xavier Garbet, Elio Sindoni, Institut de Recherche sur la Fusion par confinement Magnétique (IRFM), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
Subjects: Physics, Partial differential equation, Differential equation, Operator (physics), Gyrokinetics, Rotational symmetry, Eulerian path, neoclassical theory, Symmetry (physics), symbols.namesake, Classical mechanics, Physics::Plasma Physics, [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], symbols, Fokker–Planck equation, [NLIN]Nonlinear Sciences [physics], Rotation (mathematics)
Abstract: International audience; Conventional neoclassical predictions are successfully recovered within a gyrokinetic framework using a minimal Fokker–Planck collision operator. This operator is shown to accurately describe some essential features of neoclassical theory, namely the neoclassical transport, the poloidal rotation and the linear damping of axisymmetric flows while interestingly preserving a high numerical efficiency. Its form makes it especially adapted to Eulerian or Semi–Lagrangian schemes.
Published: 2008
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34. Progress towards steady-state operation and real-time control of internal transport barriers in JET

Author: B. C. Stratton, Y. Sarazin, X. Garbet, T. J. J. Tala, E. Joffrin, R. Dux, C. Castaldo, G. T. A. Huysmans, F. Imbeaux, Guillaume Tresset, P. Hennequin, P. Maget, F. Crisanti, Ph. Lotte, C. D. Challis, M. de Baar, N. C. Hawkes, M. Bécoulet, E. Barbato, V.V. Parail, F. Rimini, Elisabeth Rachlew, D. Frigione, J. Mailloux, K-D. Zastrow, P. Mantica, V. Pericoli, G. M. D. Hogeweij, L. G. Eriksson, C. Fourment, R. Felton, R. Cesario, Yu.F. Baranov, D. Moreau, A. Bécoulet, P. J. Lomas, L. Zabeo, T. C. Hender, D. Mazon, R. C. Wolf, R.V. Budny, M. J. Mantsinen, C. Giroud, T. Hellsten, Jet Efda contributors, X. Litaudon, P. de Vries, R. Giannella, Marco Riva, Giuseppe Gorini, Garrard Conway, B. Esposito, and O. Tudisco
Subjects: Physics, Nuclear and High Energy Physics, Jet (fluid), Tokamak, Joint European Torus, Magnetic confinement fusion, Mechanics, Condensed Matter Physics, law.invention, Bootstrap current, Shear (sheet metal), controllo, barriere termiche, law, JET, ddc:530, Current (fluid), Atomic physics, real-time control, Current density, tokamak
Abstract: In JET, advanced tokamak research mainly focuses on plasmas with internal transport barriers (ITBs) that are strongly influenced by the current density profile. A previously developed optimized shear regime with low magnetic shear in the plasma centre has been extended to deeply negative magnetic shear configurations. High fusion performance with wide ITBs has been obtained transiently with negative central magnetic shear configuration: HIPB98(y,2) ∼ 1.9, βN = 2.4 at IP = 2.5 MA. At somewhat reduced performance, electron and ion ITBs have been sustained in full current drive operation with 1 MA of bootstrap current: HIPB98(y,2) ∼ 1, βN = 1.7 at Ip = 2.0 MA. The ITBs were maintained for up to 11 s for the latter case. This duration, much larger than the energy confinement time (37 times larger), is already approaching a current resistive time. New real-time measurements and feedback control algorithms have been developed and implemented in JET for successfully controlling the ITB dynamics and the current density profile in the highly non-inductive current regime.
Published: 2003
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35. Micro-stability and transport modelling of internal transport barriers on JET

Author: X Garbet, Y Baranov, G Bateman, S Benkadda, P Beyer, R Budny, F Crisanti, B Esposito, C Figarella, C Fourment, P Ghendrih, F Imbeaux, E Joffrin, J Kinsey, A Kritz, X Litaudon, P Maget, P Mantica, D Moreau, Y Sarazin, A Pankin, V Parail, A Peeters, T Tala, G Tardini, A Thyagaraja, I Voitsekhovitch, J Weiland, R Wolf, and JET EFDA contributors
Subjects: Physics, Nuclear and High Energy Physics, Condensed matter physics, Turbulence, Tokamak, fusion reactors, Magnetic confinement fusion, Mechanics, Transport barrier, Condensed Matter Physics, Ion, fusion energy, ___, Physics::Plasma Physics, JET, internal transport barriers, Electron temperature, ddc:530, Linear growth, plasma
Abstract: Internal Transport Barriers (ITB's) in tokamak plasmas are a promising way to achieve steady-state plasmas with good confinement properties in a fusion reactor. Despite a large activity in this field, the formation and self-sustainment of barriers are still not well understood. The physics of ITB's in JET has been investigated with various techniques, namely micro-stability analysis, profile modelling and turbulence simulations. The calculation of linear growth rates show that the magnetic shear plays an important role in the formation of the ITB. The Shafranov shift, ratio of the ion to electron temperature, and impurity content further improve the stability. However the ExB velocity shear is important for the sustainment and the motion of the barrier. This picture is consistent with profile modelling and global fluid simulations of electrostatic drift waves. Turbulence simulations also show that the formation mechanisms are different for electron and ion barriers. Ion barriers are mainly due to the formation of a gap in the density of low wavenumber resonant surfaces whereas electron barriers are rather due to a reversal of the precession drift of trapped electrons.
Published: 2003
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36. Electrostatic Turbulence and Transport in Edge Plasmas: Bursts and Zonal Flows, Stochastic Field Lines, and Transport Barriers

Author: Y. Sarazin, Sadruddin Benkadda, P. Beyer, X. Garbet, and P. Ghendrih
Subjects: Physics, Tokamak, Turbulence, Mechanics, Plasma, law.invention, Magnetic field, Physics::Fluid Dynamics, Classical mechanics, Eddy, Physics::Plasma Physics, law, Relaxation (physics), Magnetohydrodynamics, Shear flow
Abstract: Turbulent transport at the edge of a tokamak plasma is characterized by the formation of two types of structures. The first are related to large scale radial transport events (bursts), the second are fluctuations of the poloidal velocity (zonal flows) that regulate transport events. These structures and their dynamics and interplay are studied by 3D numerical simulations of resistive ballooning turbulence. Additionally, a layer of stochastic magnetic field lines is considered where sheared poloidal flows are found to be strongly reduced and long lived eddies appear. As a consequence, the level of convective flux associated with fluctuations is not quenched by the magnetic field perturbation. Finally, the dynamics of transport barriers, generated by externally imposed shear flows is studied. They are found to be intermittently eroded by successions of large bursts, leading to relaxation oscillations of the barrier.
Published: 2003
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37. Perturbative transport experiments in JET low or reverse magnetic shear plasmas

Author: P Mantica, G Gorini, F Imbeaux, J Kinsey, Y Sarazin, R Budny, I Coffey, R Dux, X Garbet, L Garzotti, C Ingesson, M Kissick, V Parail, C Sozzi, A Walden, contributors to the EFDA-JET Workprogramme, Mantica, P, Gorini, G, Imbeaux, F, Kinsey, J, Sarazin, Y, Budny, R, Coffey, I, Dux, R, Garbet, X, Garzotti, L, Ingesson, C, Kissick, M, Parail, V, Sozzi, C, and Walden, A
Subjects: Physics, Jet (fluid), Magnetic confinement fusion, Context (language use), Electron, Plasma, Condensed Matter Physics, perturbative transport, JET, ITB, Pulse (physics), Shear (sheet metal), Amplitude, FIS/01 - FISICA SPERIMENTALE, Nuclear Energy and Engineering, Physics::Plasma Physics, JET, trasporto perturbato, Atomic physics, tokamak
Abstract: Perturbative transport experiments have been performed in JET low or reverse magnetic shear plasmas either in conditions of fully developed internal transport barrier (ITB) or during a phase where an ITB was not observed. Transient peripheral cooling was induced either by laser ablation or by shallow pellet injection, and the ensuing travelling cold pulse was used to probe the plasma transport in the electron and, for the first time, also in the ion channel. Cold pulses travelling through ITBs are observed to erode the ITB outer part, but, if the inner ITB portion survives, it strongly damps the propagating wave. The result is discussed in the context of proposed possible pictures for ITB formation. In the absence of an ITB, the cold pulse shows a fast propagation in the outer plasma half, which is consistent with a region of stiff transport, while in the inner half it slows down but shows the peculiar feature of amplitude growing while propagating. The data are powerful tests for the validation of theoretical transport models. This article was scheduled to appear in issue 7 of Plasma Phys. Control. Fusion. To access this Special issue please follow this link: http://stacks.iop.org/0741-3335/44/i=7
Published: 2002
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38. Micro-stability and transport modelling of internal transport barriers in JET

Author: X. Garbet (1, Y. Baranov (2, G. Bateman (3, S. Benkadda (4, P. Beyer (4, R. Budny (5, F. Crisanti (6, B. Esposito (6, C. Figarella (4, C. Fourment (1, P. Ghendrih (1, F. Imbeaux (1, E. Joffrin (1, J. Kinsey (3, A. Kritz (3, X. Litaudon (1, P. Maget (1, P. Mantica (7, D. Moreau (1, Y. Sarazin (1, A. Pankin (3, V. Parail (2, A. Peeters (10, T. Tala (9, G. Tardini (10, A. Thyagaraja (2, I. Voitsekhovitch (4, J. Weiland (8, and R. Wolf (11 and JET EFDA contributors
Subjects: ___, Physics::Plasma Physics
Abstract: The physics of ITB formation in JET has been investigated using micro-stability analysis, profile modelling and turbulence simulations. The calculation of linear growth rates show that the magnetic shear plays a crucial role in the formation of the ITB. The Shafranov shift, ratio of the ion to electron temperature, and impurity content further improve the stability. This picture is consistent with profile modelling and global fluid simulations of electrostatic drift waves. Turbulence simulations also show that rational q values may play a special role in triggering an ITB. The same physics also explains how double internal barriers can be formed.
Published: 2002

39. Improvement of LH-power coupling in H-mode and ITB plasmas on JET

Author: Y. Sarazin 1, V. Pericoli-Ridolfini 2, Y.Baranov 3, C.D. Challis 3, A. Ekedahl 1, S.K. Erents 3, G. Granucci 4, F.Imbeaux 1, E. Joffrin 1, X. Litaudon 1, P.J.Lomas 3, J. Mailloux 3, G.F.Matthews 3, S. Podda 2, E.Righi 5, F. Rimini 1, A.A. Tuccillo 2, and contributors to the EFDA-JET workprogramme
Subjects: __
Abstract: __
Published: 2001

40. LHCD coupling during H-mode and ITB in JET plasmas

Author: A. Ekedahl, Y. Baranov, S. Bernabei, S. Podda, Y. Sarazin, G. F. Matthews, V. Cocilovo, F. Rimini, A. A. Tuccillo, L. Panaccione, K. Erents, F. Leuterer, Efda-Jet Contributors, F. Imbeaux, J. Mailloux, V. P. Ridolfini, F. Mirizzi, F. Granucci, and R. Cesario
Subjects: Pedestal, Chemistry, Impurity, Electromagnetic coupling, Plasma, Atomic physics, Transport barrier, Ionization energy, __, Dissociation (chemistry)
Abstract: Good coupling of the LH power during the whole internal transport barrier (ITB) phase has been achieved in JET by fitting the plasma shape to the LH antenna shape and by injecting CD4 gas from a pipe near to the LH grill. No adverse effect on the edge pedestal or on the ITB quality, or significant impurity influx is observed. The key is the low ionization potential of all the CD4 dissociation chain, which is completed inside the SOL. Promising perspectives are open for injecting safely LHCD with more power during an ITB.
Published: 2001
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41. Characterisation of Fullerene Schottky Diodes

Author: E. Waldron, Seamus A. Curran, M. Delamesiere, C. Hogrel, D. McGoveran, J. Callaghan, E. Bourdin, Declan N. Weldon, K. Cazini, Y. Sarazin, and Werner J. Blau
Subjects: Semiconductor, Materials science, business.industry, Electron affinity, Schottky barrier, Schottky effect, Schottky diode, Optoelectronics, Semiconductor device, business, Metal–semiconductor junction, Diode
Abstract: The fabrication and characterisation of the fullerenes C60 and C70 as semiconductors in Schottky diodes are reported. The preparation of these devices involved forming a Schottky barrier between heavily doped n-Si and Ca with C70, and Mg-ln with C60. Electrical diode characteristics are determined and from these measurements both the device quality and the electron affinity of C60 and C70 were calculated. The value obtained for the electron affinity of C60 is in good agreement with other work reported in this area. In the case of n-Si/C70 Schottky diode the efficiency as a photovoltaic device was also investigated.
Published: 1993
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42. Impact of scaling laws on tokamak reactor dimensioning.

Author: Y. Sarazin, J. Hillairet, J.-L. Duchateau, K. Gaudimont, R. Varennes, X. Garbet, Ph. Ghendrih, R. Guirlet, B. Pégourié, and A. Torre
Subjects: *CRITICAL exponents, *FUSION reactors, *TECHNICAL specifications, *FUSION reactor divertors
Abstract: A simple and comprehensive method is derived and used to quantify the impact of scaling laws on tokamak reactor dimensioning. Assuming prescribed geometrical coefficients, we find the ensemble of possible triplets R, B and normalized beta which allow one to reach target fusion gain Q and fusion power , at an arbitrary Greenwald fraction. The model is generic and derived for any scaling law of the energy confinement time. Using the IPB98(y,2) scaling law (ITER Physics Expert Group on Confinement and Transport and Confinement Modeling and Database and ITER Physics Basis Editors 1999 Nucl. Fusion39 2175) leads to ITER specifications, as expected. The recently proposed new scaling law for H-mode plasmas (DS03, (Sips et al 2018 Nucl. Fusion58 126010)) is shown to lead to modest changes to the dimensioning, except for B which could be significantly smaller for the same target performance. The impact on the dimensioning of critical exponents of the scaling law—both regarding engineer and dimensionless variables—is assessed, pushing for their determination with refined accuracy. Finally, the method is applied to a DEMO-like machine. The DS03 scaling law is found to have favorable consequences on the dimensioning as compared to IPB98(y,2), provided one is able to operate at larger , which can reveal challenging in a reactor aiming at zero disruption. Importantly, the opposite scaling of both scaling laws with respect to the aspect ratio are shown to have significant consequences on the optimal choice of this critical parameter. [ABSTRACT FROM AUTHOR]
Published: 2020
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43. Quasilinear nature of L-mode edge turbulent transport in fluid nonlinear simulations.

Author: G. De Dominici, G. Fuhr, C. Bourdelle, P. Beyer, X. Garbet, Y. Sarazin, G. L. Falchetto, and Contributors, JET
Subjects: REYNOLDS stress, EDGES (Geometry), NATURE, PLASMA turbulence, PEDESTALS
Abstract: In tokamak plasma, the edge region is characterized by larger gradients, higher resisitivity and a shorter distance to the critical compared to core plasma. By edge region, we mean the region where the pedestal forms when transiting from the L to H-mode: . This paper shows, using a three-dimensional electromagnetic fluid turbulent transport model, that the quasilinear hypothesis is valid in the edge region. The diamagnetic coupling is stabilizing while is destabilizing. The effect of on the characteristic times of turbulence is studied, as is its effect on the Reynolds stress and the Maxwell stress in these fluid simulations. [ABSTRACT FROM AUTHOR]
Published: 2019
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44. Neoclassical impurity flux in presence of turbulent generated poloidal asymmetries and pressure anisotropy.

Author: P Donnel, X Garbet, Y Sarazin, V Grandgirard, N Bouzat, E Caschera, G Dif-Pradalier, P Ghendrih, C Gillot, G Latu, and C Passeron
Subjects: EDDY flux, ANISOTROPY, PRESSURE, FLUX (Energy)
Abstract: Poloidal asymmetries of impurities are commonly observed experimentally. Density asymmetry is already known to impact significantly the neoclassical prediction of impurity fluxes. In this article, the effect of impurity pressure asymmetry and anisotropy on the neoclassical flux of impurity is derived analytically. This prediction is compared with simulations performed with the gyrokinetic code GYSELA, featuring both turbulent and neoclassical transports. A fair agreement is found between the analytical prediction and the result of the simulation. On the special cases which are considered, the effects of impurity pressure asymmetry and anisotropy are shown to play a prominent role in the modification of the neoclassical impurity transport. [ABSTRACT FROM AUTHOR]
Published: 2019
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45. Gyrokinetic simulations of turbulent transport: size scaling and chaotic behaviour

Author: V. Grandgirard, Sébastien Jolliet, Trach-Minh Tran, J. Chowdhury, Yasuhiro Idomura, Alberto Bottino, Roman Hatzky, S. Khosh Aghdam, Ben F. McMillan, Laurent Villard, Guillaume Latu, T. Vernay, Tilman Dannert, A. Casati, X. Lapillonne, F. Merz, Frank Jenko, R. Ganesh, Tobias Görler, X. Garbet, Y. Sarazin, and Stephan Brunner
Subjects: Physics, Turbulence, chaos, turbulence, Chaotic, Eulerian path, Condensed Matter Physics, Supercomputer, gyrokinetic, symbols.namesake, Nuclear Energy and Engineering, Convergence (routing), symbols, Limit (mathematics), Statistical physics, Massively parallel, Scaling
Abstract: Important steps towards the understanding of turbulent transport have been made with the development of the gyrokinetic framework for describing turbulence and with the emergence of numerical codes able to solve the set of gyrokinetic equations. This paper presents some of the main recent advances in gyrokinetic theory and computing of turbulence. Solving 5D gyrokinetic equations requires state-of-the-art high performance computing techniques involving massively parallel computers and parallel scalable algorithms. The various numerical schemes that have been explored until now, Lagrangian, Eulerian and semi-Lagrangian, each have their advantages and drawbacks. A past controversy regarding the finite size effect (finite rho-star) in ITG turbulence has now been resolved. It has triggered an intensive benchmarking effort and careful examination of the convergence properties of the different numerical approaches. Now, both Eulerian and Lagrangian global codes are shown to agree and to converge to the flux-tube result in the rhostar going to 0 limit. It is found, however, that an appropriate treatment of geometrical terms is necessary: inconsistent approximations that are sometimes used can lead to important discrepancies. Turbulent processes are characterized by a chaotic behaviour, often accompanied by bursts and avalanches. Performing ensemble averages of statistically independent simulations, starting from different initial conditions, is presented as a way to assess the intrinsic variability of turbulent fluxes and obtain reliable estimates of the standard deviation. Further developments concerning non-adiabatic electron dynamics around mode-rational surfaces and electromagnetic effects are discussed.

46. Turbulence spectra and transport barriers in gyrokinetic simulations

Author: Y. Sarazin, V. Grandgirard, P. Angelino, A. Casati, G. Dif-Pradalier, X. Garbet, Ph. Ghendrih, O. Gürcan, P. Hennequin, R. Sabot, Olivier Sauter, Xavier Garbet, and Elio Sindoni
Subjects: Physics, Turbulence, Electric field, Gyrokinetics, Slab, Plasma, Atomic physics, Power law, Spectral line, Computational physics, Exponential function
Abstract: The energy spectra of the Ion Temperature Gradient driven fluctuations are investigated with the global full‐f gyrokinetic code GYSELA. For monotonous q profile, the poloidal spectrum can equally be fitted with two power laws or with a unique exponential. When prescribing an additional sheared radial electric field in view of triggering a transport barrier, the system is found to promptly polarize and screen this field, likely in a transient evolution towards a canonical equilibrium. For a reversed q profile, the negative shear region exhibits larger fluctuations, possibly due to the slab branch of ITG, characterized by a flatter spectrum. No clear transport barrier signature is observed in the vicinity of s = 0 when the radial extent of the gap without resonant modes is smaller than the turbulence correlation length.

47. Science and technology research and development in support to ITER and the Broader Approach at CEA

Author: A. Bécoulet, G.T. Hoang, J. Abiteboul, J. Achard, T. Alarcon, J. Alba-Duran, L. Allegretti, S. Allfrey, S. Amiel, J.M. Ané, T. Aniel, G. Antar, A. Argouarch, A. Armitano, J. Arnaud, D. Arranger, J.F. Artaud, D. Audisio, M. Aumeunier, E. Autissier, L. Azcona, A. Back, A. Bahat, X. Bai, B. Baiocchi, D. Balaguer, S. Balme, C. Balorin, O. Barana, D. Barbier, A. Barbuti, V. Basiuk, O. Baulaigue, P. Bayetti, C. Baylard, S. Beaufils, A. Beaute, M. Bécoulet, Z. Bej, S. Benkadda, F. Benoit, G. Berger-By, J.M. Bernard, A. Berne, B. Bertrand, E. Bertrand, P. Beyer, A. Bigand, G. Bonhomme, G. Borel, A. Boron, C. Bottereau, H. Bottollier-Curtet, C. Bouchand, F. Bouquey, C. Bourdelle, J. Bourg, S. Bourmaud, S. Brémond, F. Bribiesca Argomedo, M. Brieu, C. Brun, V. Bruno, J. Bucalossi, H. Bufferand, Y. Buravand, L. Cai, V. Cantone, B. Cantone, E. Caprin, T. Cartier-Michaud, A. Castagliolo, J. Belo, V. Catherine-Dumont, G. Caulier, J. Chaix, M. Chantant, M. Chatelier, D. Chauvin, J. Chenevois, B. Chouli, L. Christin, D. Ciazynski, G. Ciraolo, F. Clairet, R. Clapier, H. Cloez, M. Coatanea-Gouachet, L. Colas, G. Colledani, L. Commin, P. Coquillat, E. Corbel, Y. Corre, J. Cottet, P. Cottier, X. Courtois, I. Crest, R. Dachicourt, M. Dapena Febrer, C. Daumas, H.P.L. de Esch, B. De Gentile, C. Dechelle, J. Decker, P. Decool, V. Deghaye, J. Delaplanche, E. Delchambre-Demoncheaux, L. Delpech, C. Desgranges, P. Devynck, J. Dias Pereira Bernardo, G. Dif-Pradalier, L. Doceul, Y. Dong, D. Douai, H. Dougnac, N. Dubuit, J.-L. Duchateau, L. Ducobu, B. Dugue, N. Dumas, R. Dumont, A. Durocher, F. Duthoit, A. Ekedahl, D. Elbeze, A. Escarguel, J. Escop, F. Faïsse, G. Falchetto, J. Farjon, M. Faury, N. Fedorzack, P. Féjoz, C. Fenzi, F. Ferlay, P. Fiet, M. Firdaouss, M. Francisquez, B. Franel, J. Frauche, Y. Frauel, R. Futtersack, X. Garbet, J. Garcia, J. Gardarein, L. Gargiulo, P. Garibaldi, P. Garin, D. Garnier, E. Gauthier, O. Gaye, A. Geraud, M. Gerome, V. Gervaise, M. Geynet, P. Ghendrih, I. Giacalone, S. Gibert, C. Gil, S. Ginoux, L. Giovannangelo, S. Girard, G. Giruzzi, C. Goletto, R. Goncalves, R. Gonde, M. Goniche, R. Goswami, C. Grand, V. Grandgirard, B. Gravil, C. Grisolia, G. Gros, A. Grosman, J. Guigue, D. Guilhem, C. Guillemaut, B. Guillerminet, Z. Guimaraes Filho, R. Guirlet, J. P. Gunn, O. Gurcan, F. Guzman, S. Hacquin, F. Hariri, F. Hasenbeck, J.C. Hatchressian, P. Hennequin, C. Hernandez, P. Hertout, S. Heuraux, J. Hillairet, C. Honore, G. Hornung, M. Houry, I. Hunstad, T. Hutter, P. Huynh, V. Icard, F. Imbeaux, M. Irishkin, L. Isoardi, J. Jacquinot, J. Jacquot, G. Jiolat, M. Joanny, E. Joffrin, J. Johner, P. Joubert, L. Jourd'Heuil, M. Jouve, C. Junique, D. Keller, C. Klepper, D. Kogut, M. Kubič, F. Labassé, B. Lacroix, Y. Lallier, V. Lamaison, R. Lambert, S. Larroque, G. Latu, Y. Lausenaz, C. Laviron, R. Le, A. Le Luyer, C. Le Niliot, Y. Le Tonqueze, P. Lebourg, T. Lefevre, F. Leroux, L. Letellier, Y. Li, M. Lipa, J. Lister, X. Litaudon, F. Liu, T. Loarer, G. Lombard, P. Lotte, M. Lozano, J. Lucas, H. Lütjens, P. Magaud, P. Maget, R. Magne, J.-F. Mahieu, P. Maini, P. Malard, L. Manenc, Y. Marandet, G. Marbach, J.-L. Marechal, L. Marfisi, M. Marle, C. Martin, V. Martin, G. Martin, A. Martinez, P. Martino, R. Masset, D. Mazon, N. Mellet, L. Mercadier, A. Merle, D. Meshcheriakov, P. Messina, O. Meyer, L. Millon, M. Missirlian, J. Moerel, D. Molina, P. Mollard, V. Moncada, P. Monier-Garbet, D. Moreau, M. Moreau, P. Moreau, P. Morel, T. Moriyama, Y. Motassim, G. Mougeolle, D. Moulton, G. Moureau, D. Mouyon, M. Naim Habib, E. Nardon, V. Négrier, J. Nemeth, C. Nguyen, M. Nguyen, L. Nicolas, T. Nicolas, S. Nicollet, E. Nilsson, B. N'Konga, F. Noel, A. Nooman, C. Norscini, R. Nouailletas, P. Oddon, T. Ohsako, F. Orain, M. Ottaviani, M. Pagano, F. Palermo, S. Panayotis, H. Parrat, J.-Y. Pascal, C. Passeron, P. Pastor, J. Patterlini, K. Pavy, A.-L. Pecquet, B. Pégourié, C. Peinturier, T. Pelletier, B. Peluso, V. Petrzilka, Y. Peysson, E. Pignoly, R. Pirola, C. Pocheau, E. Poitevin, V. Poli, S. Poli, F. Pompon, I. Porchy, C. Portafaix, M. Preynas, P. Prochet, M. Prou, A. Ratnani, D. Raulin, N. Ravenel, S. Renard, B. Ricaud, M. Richou, G. Ritz, H. Roche, P. Roubin, C. Roux, K. Ruiz, F. Sabathier, R. Sabot, A. Saille, F. Saint-Laurent, R. Sakamoto, S. Salasca, T. Salmon, F. Samaille, S. Sanchez, A. Santagiustina, B. Saoutic, Y. Sarazin, P. Sardain, J. Schlosser, M. Schneider, J. Schwob, J. Segui, N. Seguin, G. Selig, D. Serret, J. Signoret, A. Simonin, M. Soldaini, B. Soler, C. Soltane, S. Song, F. Sourbier, J. Sparagna, P. Spitz, P. Spuig, A. Storelli, A. Strugarek, P. Tamain, M. Tena, J. Theis, O. Thomine, D. Thouvenin, A. Torre, L. Toulouse, J. Travère, E. Tsitrone, B. Turck, J. Urban, J.-C. Vallet, J. Vallory, A. Valognes, J. Van Helvoirt, S. Vartanian, J.-M. Verger, L. Vermare, C. Vermare, D. Vezinet, K. Vicente, J. Vidal, N. Vignal, T. Vigne, F. Villecroze, E. Villedieu, B. Vincent, B. Volpe, D. Volpe, R. Volpe, J. Wagrez, H. Wang, T. Wauters, O. Wintersdorff, E. Wittebol, B. Zago, L. Zani, D. Zarzoso, Y. Zhang, W. Zhong, X.L. Zou, 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), Institut Jean Lamour (IJL), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, 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), Centre de Physique Théorique [Palaiseau] (CPHT), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), and Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Nuclear and High Energy Physics, Engineering, Tokamak, business.industry, Superconducting magnet, Tore Supra, Condensed Matter Physics, 7. Clean energy, 01 natural sciences, Phase (combat), 010305 fluids & plasmas, law.invention, Procurement, Runaway electrons, law, [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], 0103 physical sciences, Systems engineering, 010306 general physics, business, ComputingMilieux_MISCELLANEOUS
Abstract: Équipe 107 : Physique des plasmas chauds; International audience; In parallel to the direct contribution to the procurement phase of ITER and Broader Approach, CEA has initiated research & development programmes, accompanied by experiments together with a significant modelling effort, aimed at ensuring robust operation, plasma performance, as well as mitigating the risks of the procurement phase. This overview reports the latest progress in both fusion science and technology including many areas, namely the mitigation of superconducting magnet quenches, disruption-generated runaway electrons, edge-localized modes (ELMs), the development of imaging surveillance, and heating and current drive systems for steady-state operation. The WEST (W Environment for Steady-state Tokamaks) project, turning Tore Supra into an actively cooled W-divertor platform open to the ITER partners and industries, is presented.
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48. The flux-coordinate independent approach applied to X-point geometries

Author: F. Hariri, Y. Sarazin, P. Hill, and M. Ottaviani
Subjects: Physics, Turbulence, Robustness (computer science), Coordinate system, Mathematical analysis, Convergence (routing), Point (geometry), Condensed Matter Physics, Anisotropy, Magnetic flux, Symmetry (physics)
Abstract: A Flux Coordinate Independent (FCI) approach for anisotropic systems, not based on magnetic flux coordinates has been introduced in [F. Hariri and M. Ottaviani, Comput. Phys. Commun., 184,2419 (2013)]. In this paper, we show that the approach can tackle magnetic configurations including X-points. Using the code FENICIA, an equilibrium with a magnetic island has been used to show the robustness of the FCI approach to cases in which a magnetic separatrix is present in the system, either by design or as a consequence of instabilities. Numerical results are in good agreement with the analytic solutions of the sound-wave propagation problem. Conservation properties are verified. Finally, the critical gain of the FCI approach in situations including the magnetic separatrix with an X-point is demonstrated by a fast convergence of the code with the numerical resolution in the direction of symmetry. The results highlighted in this paper show that the FCI approach should be able to address turbulent transport problems in X-point geometries.

49. Turbulent generation of poloidal asymmetries of the electric potential in a tokamak.

Author: P Donnel, X Garbet, Y Sarazin, E Caschera, G Dif-Pradalier, P Ghendrih, Y Asahi, F Wilczynski, and C Gillot
Subjects: TOKAMAKS, ELECTRIC potential, MAGNETIC fields, FLUX (Energy), TURBULENCE
Abstract: Poloidal asymmetries of the E × B plasma flow are known to play a role in neoclassical transport. One obvious reason is that an asymmetrical potential can produce a flux across the magnetic field. Also the associated distribution function may correlate with the magnetic drift velocity to enhance the neoclassical flux. Finally, poloidal variations of the electric potential can produce poloidal asymmetries of an impurity density, which in turn may modify the neoclassical transport coefficients. According to conventional neoclassical theory, the level of poloidal asymmetry of the electric potential is expected to be very small. Poloidal flow asymmetries can be driven by small scale turbulence via nonlinear coupling, and therefore change this result. In the present work, a general framework for the generation of axisymmetric structures of potential by turbulence is presented. Zonal flows, geodesic acoustic modes and convective cells are described by a single model. This is done by solving the gyrokinetic equation coupled to the quasi-neutrality equation. This calculation provides a predictive calculation of the frequency spectrum of flows given a specified forcing due to turbulence. It also shows that the dominant mechanism comes from zonal flow compression at intermediate frequencies, while ballooning of the turbulence Reynolds stress appears to be the main drive at low frequency. [ABSTRACT FROM AUTHOR]
Published: 2019
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50. Contribution of kinetic electrons to GAM damping.

Author: C. Ehrlacher, X. Garbet, V. Grandgirard, Y. Sarazin, P. Donnel, E. Caschera, P. Ghendrih, and D. Zarzoso
Published: 2018
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154 results on '"Y. Sarazin"'

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