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2. Design and first tests of the trapped electrons experiment T-REX.

Author

Romano, F., Le Bars, G., Loizu, J., Nöel, M., Hogge, J.-P., Alberti, S., Genoud, J., Antonioni, S., Naux, L., Giroud-Garampon, P., Couturier, S., Leresche, T., and Fasel, D.

Subjects
CYCLOTRON resonance, SUPERCONDUCTING magnets, FUSION reactors, ELECTRIC fields, MAGNETIC fields
Abstract

Gyrotrons are essential for electron cyclotron resonance heating in fusion reactors, making efficient operation crucial for advancing fusion energy. Past experiments revealed instability issues due to trapped electrons in the magnetron injection gun (MIG) region, causing undesired currents and operational failures. To address this, tight manufacturing tolerances are required for the MIG geometry [Pagonakis et al., Phys. Plasmas 23, 023105 (2016)]. We present the initial findings of the trapped electrons experiment developed at the Swiss Plasma Center, designed to understand the physics of electron clouds in gyrotron MIGs. T-REX replicates MIG geometries, as well as their typical electric and magnetic fields, and it is supported by 2D particle-in-cell simulations with the FENNECS code [Le Bars et al., Phys. Plasmas 29, 082105 (2022); Le Bars, Ph.D. thesis, EPFL, Lausanne, 2023]. The setup includes two coaxial electrodes in a vacuum chamber atop a superconducting magnet, with a central electrode biased to negative DC voltages and an outer one at the ground, creating a radial electric field (1–2 MV/m) and an axial magnetic field (B < 0.4 T). This setup mimics Penning–Malmberg traps. We present the experimental device and first findings on current distribution and also a qualitative comparison with FENNECS simulations [Le Bars et al., Comput. Phys. Commun. 303, 109268 (2024)]. Planned diagnostics include optical emission spectroscopy, phosphor screen imaging, streak camera imaging, and potentially electric field distribution via the Stark effect. This research aims to enhance gyrotron performance and reliability in fusion energy systems. [ABSTRACT FROM AUTHOR]

Published
2024
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4. Recent experiments with the European 1MW, 170GHz industrial CW and short-pulse gyrotrons for ITER

Author

Ioannidis, Z. C., Albajar, F., Alberti, S., Avramidis, K. A., Bin, W., Bonicelli, T., Bruschi, A., Chelis, J., Fanale, F., Gantenbein, G., Genoud, J., Hogge, J.-P., Hermann, V., Illy, S., Jelonnek, J., Jin, J., Kasparek, W., Latsas, G. P., Legrand, F., Lechte, C., Pagonakis, I. Gr., Rzesnicki, T., Sánchez, F., Schlatter, C., Schmid, M., Tigelis, I. G., Thumm, M., Tran, M. Q., Zisis, A., and Zein, A.

Published
2019
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6. Observation of d-wave scaling relations in the mixed-state specific heat of YBa2Cu3O7

Author

Revaz, B., Genoud, J. -Y., Junod, A., Erb, A., and Walker, E.

Subjects
Condensed Matter - Superconductivity
Abstract

The low temperature specific heat C(B,T) of an YBa2Cu3O7.00 single crystal is measured from 1.2 to 10 K in magnetic fields up to 14 T. The anisotropic component Caniso(T,B)=C(T,B//c)-C(T,B//ab) is a pure vortex quantity obtained directly from experiment. It follows a scaling relation predicted recently for line nodes characteristic of d-wave vortices. Our experimental field and temperature range corresponds to a crossover region where the limit Caniso(T,B)is proportional to T*sqrt(B) does not strictly apply. The variation of the entropy caused by the magnetic field at low T is thermodynamically compatible with measurements near Tc., Comment: submitted to Phys. Rev. Lett. PDF file, 18 pages

Published
1997
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9. Tests and Qualification of the European 1 MW, 170 GHz CW Gyrotron in an ITER relevant configuration at SPC

Author

Goodman, T. P., Alberti, S., Genoud, J., Torreblanca, H., Albajar, F., Sanchez, F., Leggieri, A., Legrand, F., Lievin, C., Ioannidis, Z., Avramidis, K. A., Tigelis, I, Illy, S., and Hogge, J-P

Subjects
Technology, ddc:600
Abstract

After an initial testing period at the Karlsruhe Institute of Technology, the upgraded EU 1 MW, 170 GHz continuous wave (CW) industrial prototype gyrotron (TH1509U) for Electron Cyclotron Resonance Heating and Current Drive (ECRH&CD) in ITER has been transferred to the Swiss Plasma Center (SPC) to be tested in an ITER relevant configuration, to reach the performance level required by Fusion for Energy (F4E) to qualify it for the ITER project, and to increase the pulse length to very long pulses.

Published
2022
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10. Combined Bacterial Meningitis and Infective Endocarditis: When Should We Search for the Other When Either One is Diagnosed?

Author

Béraud, Guillaume, Tubiana, Sarah, Erpelding, Marie-Line, Le Moing, Vincent, Chirouze, Catherine, Gorenne, Isabelle, Manchon, Pauline, Tattevin, Pierre, Vernet, Veronique, Varon, Emmanuelle, Hoen, Bruno, Duval, Xavier, Obadia, J., Leport, C., Poyart, C., Revest, M., Selton-Suty, C., Strady, C., Vandenesch, F., Bernard, Y., Chocron, S., Plesiat, P., Abouliatim, I., de Place, C., Donnio, P., Alla, F., Carteaux, J., Doco-Lecompte, T., Lion, C., Aissa, N., Baehrel, B., Jaussaud, R., Nazeyrollas, P., Cambau, E., Iung, B., Nataf, P., Chidiac, C., Celard, M., Delahaye, F., Aumaître, H., Frappier, J., Oziol, E., Sotto, A., Sportouch, C., Bouvet, A., Bes, M., Abassade, P., Abrial, E., Acar, C., Alexandra, J., Amireche, N., Amrein, D., Andre, P., Appriou, M., Arnould, M., Atoui, A., Aziza, F., Baille, N., Bajolle, N., Battistella, P., Baumard, S., Ben Ali, A., Bertrand, J., Bialek, S., Bois Grosse, M., Boixados, M., Borlot, F., Bouchachi, A., Bouche, O., Bouchemal, S., Bourdon, J., Brasme, L., Bruntz, J., Cailhol, J., Caplan, M.P., Carette, B., Cartry, O., Cazorla, C., Chamagne, H., Champagne, H., Chanques, G., Chevalier, B., Chometon, F., Christophe, C., Colin de Verdiere, N., Daneluzzi, V., David, L., Danchin, N., de Lentdecker, P., Delcey, V., Deleuze, P., Deroure, B., Descotes-Genon, V., Didier Petit, K., Dinh, A., Doat, V., Duchene, F., Duhoux, F., Dupont, M., Ederhy, S., Epaulard, O., Evest, M., Faucher, J., Fauveau, E., Ferry, T., Fillod, M., Floch, T., Fraisse, T., Frapier, J., Freysz, L., Fumery, B., Gachot, B., Gallien, S., Garcon, P., Gaubert, A., Genoud, J., Ghiglione, S., Godreuil, C., Gandjbakhch, I., Grentzinger, A., Groben, L., Gherissi, D., Hagege, A., Hammoudi, N., Heliot, F., Henry, P., Houriez, P., Hustache-Mathieu, L., Huttin, O., Imbert, S., Jaureguiberry, S., Kaaki, M., Konate, A., Kuhn, J., Kural Menasche, S., Lafitte, A., Lafon, B., Lanternier, F., Le Chenault, V., Lechiche, C., Lefevre Thibaut, S., Lefort, A., Lemoine, J., Lepage, L., Lepousé, C., Leroy, J., Lesprit, P., Letranchant, L., Loncar, G., Lorentz, C., Magnin-Poull, I., Makinson, A., Man, H., Mansouri, M., Marçon, O., Maroni, J., Masse, V., Maurier, F., Mechaï, F., Merceron, O., Messika-Zeitoun, D., Metref, Z., Meyssonnier, V., Mezher, C., Micheli, S., Monsigny, M., Mouly, S., Mourvillier, B., Nallet, O., Nazerollas, P., Noel, V., Payet, B., Pelletier, A., Perez, P., Petit, J., Philippart, F., Piet, E., Plainvert, C., Popovic, B., Porte, J., Pradier, P., Ramadan, R., Richemond, J., Rodermann, M., Roncato, M., Roigt, I., Ruyer, O., Saada, M., Schwartz, J., Simon, M., Simorre, B., Skalli, S., Spatz, F., Sudrial, J., Tartiere, L., Terrier de La Chaize, A., Thiercelin, M., Thomas, D., Thomas, M., Toko, L., Tournoux, F., Tristan, A., Trouillet, J., Tual, L., Verdier, F., Vernet Garnier, V., Vidal, V., Weyne, P., Wolff, M., Wynckel, A., Zannad, N., Zinzius, P., Ploy, M.-C., Caron, F., Bollaert, P.-E., Gaillot, O., Taha, M.-K., Bonacorsi, S., Lecuit, M., Gravet, A., Frachet, B., Debroucker, T., Levy-Bruhl, D., Raffi, F., Preau, M., Anguel, N., Argaud, L., Arista, S., Armand-Lefevre, L., Balavoine, S., Baraduc, R., Barnaud, G., Bernard, L., Bernars, G., Bertei, D., Bessede, E., Billard Pomares, T., Biron, C., Bland, S., Boileau, J., Boubeau, P., Bourdon, S., Bousquet, A., Boyer, S., Bozorg-Grayeli, A., Bret, L., Bretonniere, C., Bricaire, F., Brocas, E., Brun, M., Buret, J., Burucoa, C., Cabalion, J., Cabon, M., Camuset, G., Canevet, C., Carricajo, A., Castan, B., Caumes, E., Cazanave, C., Chabrol, A., Challan-Belval, T., Chanteperdrix-Marillier, V., Chaplain, C., Charlier-Woerther, C., Chaussade, H., Clair, B., Colot, J., Conil, J.-M., Cordel, H., Cormier, P., Cousson, J., Cronier, P., Cua, E., Dao-Dubremetz, A., Dargere, S., Degand, N., Dekeyser, S., Delaune, D., Denes, E., Dequin, P.-F., Descamps, D., Descloux, E., Desmaretz, J.-L., Diehl, J.-L., Dimet, J., Escaut, L., Fabe, C., Faibis, F., Flateau, C., Fonsale, N., Forestier, E., Fortineau, N., Gagneux-Brunon, A., Garandeau, C., Garcia, M., Garot, D., Gaudry, S., Goehringer, F., Gregoire-Faucher, V., Grosset, M., Gubavu, C., Gueit, I., Guelon, D., Guimard, T., Guinard, J., Hadou, T., Helene, J.-P., Henard, S., Henry, B., Hochart, A.-C., Illes, G., Jaffuel, S., Jarrin, I., Jaureguy, F., Joseph, C., Juvin, M.-E., Kayal, S., Kerneis, S., Lacassin, F., Lamaury, I., Lanotte, P., Laurens, E., Laurichesse, H., Le Brun, C., Le Turnier, P., Lecuyer, H., Ledru, S., Legrix, C., Lemaignen, A., Lemble, C., Lemee, L., Lesens, O., Levast, M., Lhommet, C., Males, S., Malpote, E., Martin-Blondel, G., Marx, M., Masson, R., Matray, O., Mbadi, A., Mellon, G., Merens, A., Meyohas, M.-C., Michon, A., Mootien Yoganaden, J., Morquin, D., Mrozek, N., Nguyen, S., Nguyen, Y., Ogielska, M., Page, B., Patrat-Delon, S., Patry, I., Pechinot, A., Picot, S., Pierrejean, D., Piroth, L., Plassart, C., Plessis, P., Portel, L., Poubeau, P., Poupard, M., Prazuck, T., Quaesaet, L., Ramanantsoa, A., Rapp, C., Raskine, L., Raymond, J., Riche, A., Robaday-Voisin, S., Robin, F., Romaszko, J.-P., Rousseau, F., Roux, A.-L., Royer, C., Salmon, D., Saroufim, C., Schmit, J.-L., Sebire, M., Segonds, C., Sivadon-Tardy, V., Soismier, N., Son, O., Sunder, S., Suy, F., Tande, D., Tankovic, J., Valin, N., van Grunderbeeck, N., Verdon, R., Vergnaud, M., Vernet-Garnier, V., Vidal, M., Vitrat, V., Vittecoq, D., Vuotto, F., Laouenan, C., Marcault, E., Mentre, F., Pasquet, B., Roy, C., Centre hospitalier universitaire de Poitiers (CHU Poitiers), Centre d'investigation Clinique [CHU Bichat] - Épidémiologie clinique (CIC 1425), AP-HP - Hôpital Bichat - Claude Bernard [Paris], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Institut National de la Santé et de la Recherche Médicale (INSERM), Infection, Anti-microbiens, Modélisation, Evolution (IAME (UMR_S_1137 / U1137)), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Paris Cité (UPCité)-Université Sorbonne Paris Nord, Centre d'investigation clinique [Nancy] (CIC), Centre Hospitalier Régional Universitaire de Nancy (CHRU Nancy)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Lorraine (UL), Laboratoire Chrono-environnement (UMR 6249) (LCE), Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), CHU Pontchaillou [Rennes], ARN régulateurs bactériens et médecine (BRM), Université de Rennes (UR)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Structure Fédérative de Recherche en Biologie et Santé de Rennes ( Biosit : Biologie - Santé - Innovation Technologique ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Paris Cité (UPC)-Université Sorbonne Paris Nord, Centre d'investigation clinique - Epidémiologie clinique [Nancy] (CIC-EC), Centre Hospitalier Régional Universitaire de Nancy (CHRU Nancy)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Lorraine (UL)-Centre Hospitalier Régional Universitaire de Nancy (CHRU Nancy)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Lorraine (UL), CHU Montpellier, Centre Hospitalier Régional Universitaire [Montpellier] (CHRU Montpellier), Laboratoire Chrono-environnement - CNRS - UBFC (UMR 6249) (LCE), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Structure Fédérative de Recherche en Biologie et Santé de Rennes ( Biosit : Biologie - Santé - Innovation Technologique ), Centre Hospitalier Universitaire de Reims (CHU Reims), Centre Hospitalier Intercommunal de Créteil (CHIC), Centre Hospitalier Régional Universitaire de Nancy (CHRU Nancy), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Physiologie & médecine expérimentale du Cœur et des Muscles [U 1046] (PhyMedExp), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and The AEPEI IE cohort was funded by a research grant from the French Ministry of Health (PHRC 2007), grants from the Société Française de Cardiologie, the European Society of Clinical Microbiology and Infectious Diseases, and Novartis France. The sponsor was Délégation à la Recherche Clinique et au Développement, Centre Hospitalier Universitaire de Besançon. The COMBAT cohort was funded by Assistance Publique—Hôpitaux de Paris, Inserm, The French Society of Infectious Diseases (SPILF), and Pfizer Laboratory. It was also supported by the Observatoire de la Resistance du Pneumocoque (ORP) and Santé Publique France. The sponsor of the study and the funding sources had no role in study design, data collection, data analysis, data interpretation or writing of the report. The corresponding author had full access to all the data in the study and had final responsibility for the decision to submit it for publication. The Rapid Service Fee was funded by the University Hospital of Poitiers, to which the corresponding author is affiliated.

Subjects
Microbiology (medical), Infectious Diseases, [SDV.MHEP.MI]Life Sciences [q-bio]/Human health and pathology/Infectious diseases, Echocardiography, Austrian syndrome, Staphylococcus, [SDV]Life Sciences [q-bio], Bacterial meningitis, Streptococcus, Infective endocarditis
Abstract

International audience; Introduction: We aimed to describe patients with coexisting infective endocarditis (IE) and bacterial meningitis (BM).Methods: We merged two large prospective cohorts, an IE cohort and a BM cohort, with only cases of definite IE and community-acquired meningitis. We compared patients who had IE and BM concurrently to patients with IE only and BM only.Results: Among the 1030 included patients, we identified 42 patients with IE-BM (4.1%). Baseline characteristics of patients with IE-BM were mostly similar to those of patients with IE, but meningitis was the predominant presentation at admission (39/42, 92.3%). Causative pathogens were predominantly Streptococcus pneumoniae (18/42, 42.9%) and Staphylococcus aureus (14/42, 33.3%). All pneumococcal IE were associated with BM (18/18). BM due to oral and group D streptococci, Streptococcus agalactiae, and S. aureus were frequently associated with IE (14/30, 46.7%). Three-month mortality was 28.6% in patients with IE-BM, 20.5% in patients with IE, and 16.6% in patients with BM.Conclusions: Patients with pneumococcal IE or altered mental status during IE must be investigated for BM. Patients with S. aureus, oral and group D streptococcal or enterococcal BM, or unfavorable outcome in pneumococcal meningitis would benefit from an echocardiography. Patients with the dual infection have the worst prognosis. Their identification is mandatory to initiate appropriate treatment.

Published
2022
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13. Generation of nanosecond THz pulses using a high gain ring resonator with a semiconductor switch

Author

Massachusetts Institute of Technology. Department of Physics, Massachusetts Institute of Technology. Plasma Science and Fusion Center, Genoud, J., Claveau, E. L., Jawla, S. K., Li, G., Picard, J. F., Shapiro, M. A., Temkin, R. J., Massachusetts Institute of Technology. Department of Physics, Massachusetts Institute of Technology. Plasma Science and Fusion Center, Genoud, J., Claveau, E. L., Jawla, S. K., Li, G., Picard, J. F., Shapiro, M. A., and Temkin, R. J.

Abstract

A [Formula: see text] quasi-optical ring resonator consisting of an input coupler and three mirrors has been designed and tested. A low-loss silicon wafer in the ring provides output coupling of the stored power when irradiated by a pulse from a [Formula: see text] laser. The ring created [Formula: see text] output power pulses when excited by a [Formula: see text] continuously operating input source, achieving a power gain of 16. In a fully tuned ring, higher gain is achievable. If the ring was used with a pulsed input source having a pulse length of several times the fill time, the ring could be used as an efficient pulse compressor with similar high gain. The resonator has a wide range of applications, including, at low power, spectroscopy and, at high power, testing of accelerator structures and materials.

Published
2022

15. Generalized Radiation Boundary Conditions in Gyrotron Oscillator Modeling

Author

Alberti, S., Tran, T., Brunner, S., Braunmueller, F., Genoud, J., Hogge, J.-Ph, Tran, M., Alberti, S., Tran, T., Brunner, S., Braunmueller, F., Genoud, J., Hogge, J.-Ph, and Tran, M.

Abstract

A numerical procedure to implement a frequency-independent generalized non-reflecting radiation boundary conditions, GNRBC, based on the Laplace Transform, is described in details and tested successfully on a simple 2 frequency test problem. In the case of non-stationary regimes occurring in gyrotron oscillators, it is shown that the reflection at frequencies significantly separated from the carrier frequency can be effectively suppressed by this method. A detailed analysis shows that this numerical approach can be consistently used only for models in which there is no assumed separation of time scales between the RF field envelope time-evolution and the electron time of flight across the interaction region. The GNRBC has been implemented in a nonlinear time-dependent self-consistent monomode model, TWANGpic, in which there is no time scale separation since the RF field envelope is updated at each integration time step of the electron motion. The illustration of the effectiveness of the GNRBC is made with TWANGpic on a gyrotron for which extensive theoretical and experimental results have been performed.

Published
2021

22. Megawatt power generation of the dual-frequency gyrotron for TCV at 84 and 126 GHz, in long pulses

Author

Hogge, J.-P., primary, Alberti, S., additional, Avramidis, K. A., additional, Bruschi, A., additional, Bin, W., additional, Cau, F., additional, Cismondi, F., additional, Dubray, J., additional, Fasel, D., additional, Gantenbein, G., additional, Garavaglia, S., additional, Genoud, J., additional, Goodman, T. P., additional, Illy, S., additional, Jin, J., additional, Legrand, F., additional, Marchesin, R., additional, Marlétaz, B., additional, Masur, J., additional, Moro, A., additional, Moura, C., additional, Pagonakis, I. Gr., additional, Périal, E., additional, Savoldi, L., additional, Scherer, T., additional, Siravo, U., additional, Thumm, M., additional, Toussaint, M., additional, and Tran, M.-Q., additional

Published
2020
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28. Recent experiments with the European 1MW, 170GHz industrial CW and short-pulse gyrotrons for ITER

Author

Ioannidis, Z.C. Albajar, F. Alberti, S. Avramidis, K.A. Bin, W. Bonicelli, T. Bruschi, A. Chelis, J. Fanale, F. Gantenbein, G. Genoud, J. Hogge, J.-P. Hermann, V. Illy, S. Jelonnek, J. Jin, J. Kasparek, W. Latsas, G.P. Legrand, F. Lechte, C. Pagonakis, I.G. Rzesnicki, T. Sánchez, F. Schlatter, C. Schmid, M. Tigelis, I.G. Thumm, M. Tran, M.Q. Zisis, A. Zein, A.

Abstract

The European Gyrotron Consortium (EGYC) is developing the European 1 MW, 170 GHz Continuous Wave (CW) industrial prototype gyrotron for ITER in cooperation with Thales Electron Devices (TED) and Fusion for Energy (F4E). This conventional, hollow-cavity gyrotron, is based on the 1 MW, 170 GHz Short-Pulse (SP) modular gyrotron that has been designed and manufactured by the Karlsruhe Institute of Technology (KIT) in collaboration with TED. Both gyrotrons have been tested successfully in multiple experiments. In this work we briefly report on the results with the CW gyrotron at KIT and we focus at the experiments at the Swiss Plasma Center (SPC). In addition, we present preliminary results from various upgrades of the SP tube that are currently tested at KIT. © 2018

Published
2019

29. Overview of recent gyrotron R&D towards DEMO within EUROfusion Work Package Heating and Current Drive

Author

Avramidis, K.A. Aiello, G. Alberti, S. Brücker, P.T. Bruschi, A. Chelis, I. Franke, T. Gantenbein, G. Garavaglia, S. Genoud, J. George, M. Granucci, G. Grossetti, G. Hogge, J.-P. Illy, S. Ioannidis, Z.C. Jelonnek, J. Jin, J. Kalaria, P.C. Latsas, G.P. Marek, A. Pagonakis, I.G. Peponis, D.V. Ruess, S. Ruess, T. Rzesnicki, T. Scherer, T. Schmid, M. Strauss, D. Thumm, M. Tigelis, I. Wu, C. Zein, A. Zisis, A. Tran, M.Q.

Abstract

Gyrotron R&D within the EUROfusion Work Package Heating and Current Drive (WPHCD) is addressing the challenging requirements posed on gyrotrons by the European concept for a demonstration fusion power plant (EU DEMO). These requirements, as specified within WPHCD, ask for highly reliable and robust long-pulse operation of the gyrotron, delivering 2 MW of microwave power at frequencies above 200 GHz with a high overall efficiency above 60% and the option for fast frequency step-tunability. To meet these targets, which are clearly beyond today's state-of-the-art, the R&D activities within WPHCD are organized in five main branches: these are the experimental verification of the advanced coaxial gyrotron technology at long pulses, the development of a coaxial gyrotron meeting the EU DEMO requirements, the development of multi-stage depressed collectors for enhanced energy recovery, the development of large broadband diamond windows to allow fast frequency tunability of the gyrotron, and the studies on further innovations and improvement of critical gyrotron components, in view of optimization of performance, reliability, and industrialization. The paper presents the progress made on these activities, the recent results, and the near-term planning. The major recent achievements include (i) the experimental validation of the fabrication of the new, water-cooled components for the longer-pulse coaxial gyrotron at Karlsruhe Institute of Technology, by demonstrating 2.2 MW at 170 GHz with 33% efficiency without depressed collector, (ii) the design of key components for a 2 MW, 170/204 GHz dual-frequency coaxial gyrotron, (iii) the design of a two-stage depressed collector with 77% efficiency, (iv) the first-ever production, in an industrial plasma reactor, of large chemical vapor deposition diamond wafers of 180 mm diameter, (v) the procurement of an advanced electron gun with coated emitter edges, and (vi) advances in the theoretical and numerical modelling for investigating improved concepts for the gyrotron beam tunnel and cavity. © EURATOM 2019.

Published
2019

30. Modeling of parasitic oscillations in smooth-wall circular symmetric dielectric-loaded gyrotron beam ducts

Author

Genoud, J. Alberti, S. Hogge, J.-P. Tigelis, I.G. Latsas, G.P. Chelis, I.G.

Abstract

The self-consistent simulation of the electron beam interaction was performed in the presence of a lossy dielectric layer in the smooth-wall beam duct of a gyrotron oscillator. For this purpose, the linear and spectral code TWANGlinspec was extended. In this code, the local transverse structure of the TE mode is adapted to the solution of the complex cold dispersion relation of an infinite, homogeneous, dielectric coated cylindrical waveguide. Before considering the realistic situation, the validity of the TE pure mode (Ez = 0) assumed in TWANGlinspec had to be assessed for SiC or BeOSiC materials. The effect of the dielectric layer on the parasitic starting current is large for parasitic oscillations localized at the end of the beam duct and in the so-called spacer region. For the realistic case, the geometry of the dual frequency gyrotron for the Tokamak à Configuration Variable was considered, and the effect of a dielectric layer was numerically investigated. The electron beam velocity spread was also included in the simulations. The result is that in such conditions, the parasitic oscillation starting currents are increased above the operating beam current. The observation of these spurious modes would therefore not be expected. © 2019 Author(s).

Published
2019

31. Simple Scoring System to Predict In‐Hospital Mortality After Surgery for Infective Endocarditis

Author

Gatti, Giuseppe, Perrotti, Andrea, Obadia, Jean-François, Duval, Xavier, Iung, Bernard, Alla, François, Chirouze, Catherine, Selton-Suty, Christine, Hoen, Bruno, Sinagra, Gianfranco, Delahaye, François, Tattevin, Pierre, Le Moing, Vincent, Pappalardo, Aniello, Chocron, Sidney, Hoen, B., Duval, X., Alla, F., Bouvet, A., Briancon, S., Cambau, E., Celard, M., Chirouze, C., Danchin, N., Doco-Lecompte, T., Delahaye, F., Etienne, J., Iung, B., Le Moing, V., Obadia, J. F., Leport, C., Poyart, C., Revest, M., Selton-Suty, C., Strady, C., Tattevin, P., Vandenesch, F., Bernard, Y., Chocron, S., Plesiat, P., Abouliatim, I., De Place, C., Donnio, P. Y., Carteaux, J. P., Lion, C., Aissa, N., Baehrel, B., Jaussaud, R., Nazeyrollas, P., Vernet, V., Nataf, P., Chidiac, C., Aumaître, H., Frappier, J. M., Oziol, E., Sotto, A., Sportouch, C., Bes, M., Abassade, P., Abrial, E., Acar, C., Alexandra, J. F., Amireche, N., Amrein, D., Andre, P., Appriou, M., Arnould, M. A., Assayag, P., Atoui, A., Aziza, F., Baille, N., Bajolle, N., Battistella, P., Baumard, S., Ben Ali, A., Bertrand, J., Bialek, S., Bois Grosse, M., Boixados, M., Borlot, F., Bouchachi, A., Bouche, O., Bouchemal, S., Bourdon, J. L., Brasme, L., Bricaire, F., Brochet, E., Bruntz, J. F., Cady, A., Cailhol, J., Caplan, M. P., Carette, B., Cartry, O., Cazorla, C., Chamagne, H., Champagne, H., Chanques, G., Chastre, J., Chevalier, B., Chometon, F., Christophe, C., Cohen, A., Colin de Verdiere, N., DANELUZZI, VALERIA, David, L., De Lentdecker, P., Delcey, V., Deleuze, P., Donal, E., Deroure, B., Descotes-Genon, V., Didier Petit, K., Dinh, A., Doat, V., Duchene, F., Duhoux, F., Dupont, M., Ederhy, S., Epaulard, O., Evest, M., Faucher, J. F., FANTIN, BARBARA, Fauveau, E., Ferry, T., Fillod, M., Floch, T., Fraisse, T., Frapier, J. M., Freysz, L., Fumery, B., Gachot, B., Gallien, S., Gandjbach, I., Garcon, P., Gaubert, A., Genoud, J. L., Ghiglione, S., Godreuil, C., Grentzinger, A., Groben, L., Gherissi, D., Guéret, P., Hagege, A., Hammoudi, N., Heliot, F., Henry, P., Herson, S., Houriez, P., Hustache-Mathieu, L., Huttin, O., Imbert, S., Jaureguiberry, S., Kaaki, M., Konate, A., Kuhn, J. M., Kural Menasche, S., Lafitte, A., Lafon, B., Lanternier, F., Le Chenault, V., Lechiche, C., Lefèvre-Thibaut, S., Lefort, A., Leguerrier, A., Lemoine, J., Lepage, L., Lepouse', C., Leroy, J., Lesprit, P., Letranchant, L., Loisance, D., Loncar, G., Lorentz, C., Mabo, P., Magnin-Poull, I., May, T., Makinson, A., Man, H., Mansouri, M., Marxcon, O., Maroni, J. P., Masse, V., Maurier, F., Meyohas, M. C., Michel, P. L., Michelet, C., Mechaï, F., Merceron, O., Messika-Zeitoun, D., Metref, Z., Meyssonnier, V., Mezher, C., Micheli, S., Monsigny, M., Mouly, S., Mourvillier, B., Nallet, O., Noel, V., Papo, T., Payet, B., Pelletier, A., Perez, P., Petit, J. S., Philippart, F., Piet, E., Plainvert, C., Popovic, B., Porte, J. M., Pradier, P., Ramadan, R., Richemond, J., Rodermann, M., Roncato, M., Roigt, I., Ruyer, O., Saada, M., Schwartz, J., Simon, M., Simorre, B., Skalli, S., Spatz, F., Sudrial, J., Tartiere, L., Terrier De La Chaise, A., Thiercelin, M. C., Thomas, D., Thomas, M., Toko, L., Tournoux, F., Tristan, A., Trouillet, J. L., Tual, L., Vahanian, A., Verdier, F., Vernet Garnier, V., vidal, valentina, Weyne, P., Wolff, M., Wynckel, A., Zannad, N., Zinzius, P. Y., University hospital of Trieste, Marqueurs pronostiques et facteurs de régulations des pathologies cardiaques et vasculaires - UFC ( UR 3920) (PCVP / CARDIO), Centre Hospitalier Régional Universitaire de Besançon (CHRU Besançon)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Hôpital Louis Pradel [CHU - HCL], Hospices Civils de Lyon (HCL), Infection, Anti-microbiens, Modélisation, Evolution (IAME (UMR_S_1137 / U1137)), Université Paris 13 (UP13)-Université Paris Diderot - Paris 7 (UPD7)-Université Sorbonne Paris Cité (USPC)-Institut National de la Santé et de la Recherche Médicale (INSERM), CIC Bichat (CIC1425), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Institut National de la Santé et de la Recherche Médicale (INSERM), DHU FIRE Centre de compétence des maladies pulmonaires rares, Service de cardiologie, Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-AP-HP - Hôpital Bichat - Claude Bernard [Paris], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Maladies chroniques, santé perçue, et processus d'adaptation (APEMAC), Université de Lorraine (UL), Service des maladies infectieuses et tropicales, Centre Hospitalier Régional Universitaire de Besançon (CHRU Besançon), Institut Lorrain du Coeur et des Vaisseaux Louis Mathieu [Nancy], Service de Cardiologie [CHRU Nancy], Centre Hospitalier Régional Universitaire de Nancy (CHRU Nancy), Service des Maladies Infectieuses et Tropicales [Point-à-Pitre, Guadeloupe], CHU Pointe-à-Pitre/Abymes [Guadeloupe], Service des maladies infectieuses et réanimation médicale [Rennes] = Infectious Disease and Intensive Care [Rennes], CHU Pontchaillou [Rennes], Recherches Translationnelles sur le VIH et les maladies infectieuses endémiques et émergentes (TransVIHMI), Institut de Recherche pour le Développement (IRD)-Université de Yaoundé I-Université Cheikh Anta Diop [Dakar, Sénégal] (UCAD)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Montpellier (UM), Dr Duval reports grants from Pfizer Inc (New York, NY) outside the submitted work, Association for the Study and Prevention of Infective Endocarditis Study Group–Association pour l’ Etude et la Prevention de l’Endocadite Infectieuse, Modèles et méthodes de l'évaluation thérapeutique des maladies chroniques (U738 / UMR_S738), Université Paris Diderot - Paris 7 (UPD7)-Institut National de la Santé et de la Recherche Médicale (INSERM), Université Paris Diderot - Paris 7 (UPD7)-AP-HP - Hôpital Bichat - Claude Bernard [Paris]-Assistance publique - Hôpitaux de Paris (AP-HP) (APHP), Département de Santé Publique [Paris], Institut de recherche en santé publique [Paris], Laboratoire Chrono-environnement - UFC (UMR 6249) (LCE), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Centre Hospitalier Régional Universitaire [Besançon] (CHRU Besançon)-Hôpital Saint-Jacques, Centre Michel de Boüard - Centre de recherches archéologiques et historiques anciennes et médiévales (CRAHAM), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS), Recherches Translationnelles sur le VIH et les maladies infectieuses (TransVIHMI), Université Montpellier 1 (UM1)-Institut de Recherche pour le Développement (IRD)-Université Cheikh Anta Diop [Dakar, Sénégal] (UCAD)-Universtié Yaoundé 1 [Cameroun]-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Montpellier (UM), Marqueurs pronostiques et facteurs de régulations des pathologies cardiaques et vasculaires - UFC ( EA 3920) (PCVP / CARDIO), Centre Hospitalier Régional Universitaire [Besançon] (CHRU Besançon)-Université de Franche-Comté (UFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Paris 13 (UP13)-Université Paris Diderot - Paris 7 (UPD7)-Université Sorbonne Paris Cité (USPC), Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-Institut National de la Santé et de la Recherche Médicale (INSERM), Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-AP-HP - Hôpital Bichat - Claude Bernard [Paris], Centre Hospitalier Régional Universitaire [Besançon] (CHRU Besançon)-Hôpital Jean Minjoz, Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Recherche pour le Développement (IRD)-Université Montpellier 1 (UM1)-Université Cheikh Anta Diop [Dakar, Sénégal] (UCAD)-Universtié Yaoundé 1 [Cameroun]-Université de Montpellier (UM), Centre d'Investigation Clinique Antilles Guyane, Inserm CIC1424, Recherches Translationnelles sur le VIH et les maladies infectieuses endémiques er émergentes (TransVIHMI), Modèles et méthodes de l'évaluation thérapeutique des maladies chroniques, Gatti, Giuseppe, Perrotti, Andrea, Obadia, Jean-Françoi, Duval, Xavier, Iung, Bernard, Alla, Françoi, Chirouze, Catherine, Selton-Suty, Christine, Hoen, Bruno, Sinagra, Gianfranco, Delahaye, Françoi, Tattevin, Pierre, Le Moing, Vincent, Pappalardo, Aniello, Chocron, Sidney, Hoen, B., Duval, X., Alla, F., Bouvet, A., Briancon, S., Cambau, E., Celard, M., Chirouze, C., Danchin, N., Doco-Lecompte, T., Delahaye, F., Etienne, J., Iung, B., Le Moing, V., Obadia, J. F., Leport, C., Poyart, C., Revest, M., Selton-Suty, C., Strady, C., Tattevin, P., Vandenesch, F., Bernard, Y., Chocron, S., Plesiat, P., Abouliatim, I., De Place, C., Donnio, P. Y., Carteaux, J. P., Lion, C., Aissa, N., Baehrel, B., Jaussaud, R., Nazeyrollas, P., Vernet, V., Nataf, P., Chidiac, C., Aumaître, H., Frappier, J. M., Oziol, E., Sotto, A., Sportouch, C., Bes, M., Abassade, P., Abrial, E., Acar, C., Alexandra, J. F., Amireche, N., Amrein, D., Andre, P., Appriou, M., Arnould, M. A., Assayag, P., Atoui, A., Aziza, F., Baille, N., Bajolle, N., Battistella, P., Baumard, S., Ben Ali, A., Bertrand, J., Bialek, S., Bois Grosse, M., Boixados, M., Borlot, F., Bouchachi, A., Bouche, O., Bouchemal, S., Bourdon, J. L., Brasme, L., Bricaire, F., Brochet, E., Bruntz, J. F., Cady, A., Cailhol, J., Caplan, M. P., Carette, B., Cartry, O., Cazorla, C., Chamagne, H., Champagne, H., Chanques, G., Chastre, J., Chevalier, B., Chometon, F., Christophe, C., Cohen, A., Colin de Verdiere, N., Daneluzzi, Valeria, David, L., De Lentdecker, P., Delcey, V., Deleuze, P., Donal, E., Deroure, B., Descotes-Genon, V., Didier Petit, K., Dinh, A., Doat, V., Duchene, F., Duhoux, F., Dupont, M., Ederhy, S., Epaulard, O., Evest, M., Faucher, J. F., Fantin, Barbara, Fauveau, E., Ferry, T., Fillod, M., Floch, T., Fraisse, T., Frapier, J. M., Freysz, L., Fumery, B., Gachot, B., Gallien, S., Gandjbach, I., Garcon, P., Gaubert, A., Genoud, J. L., Ghiglione, S., Godreuil, C., Grentzinger, A., Groben, L., Gherissi, D., Guéret, P., Hagege, A., Hammoudi, N., Heliot, F., Henry, P., Herson, S., Houriez, P., Hustache-Mathieu, L., Huttin, O., Imbert, S., Jaureguiberry, S., Kaaki, M., Konate, A., Kuhn, J. M., Kural Menasche, S., Lafitte, A., Lafon, B., Lanternier, F., Le Chenault, V., Lechiche, C., Lefèvre-Thibaut, S., Lefort, A., Leguerrier, A., Lemoine, J., Lepage, L., Lepouse', C., Leroy, J., Lesprit, P., Letranchant, L., Loisance, D., Loncar, G., Lorentz, C., Mabo, P., Magnin-Poull, I., May, T., Makinson, A., Man, H., Mansouri, M., Marxcon, O., Maroni, J. P., Masse, V., Maurier, F., Meyohas, M. C., Michel, P. L., Michelet, C., Mechaï, F., Merceron, O., Messika-Zeitoun, D., Metref, Z., Meyssonnier, V., Mezher, C., Micheli, S., Monsigny, M., Mouly, S., Mourvillier, B., Nallet, O., Noel, V., Papo, T., Payet, B., Pelletier, A., Perez, P., Petit, J. S., Philippart, F., Piet, E., Plainvert, C., Popovic, B., Porte, J. M., Pradier, P., Ramadan, R., Richemond, J., Rodermann, M., Roncato, M., Roigt, I., Ruyer, O., Saada, M., Schwartz, J., Simon, M., Simorre, B., Skalli, S., Spatz, F., Sudrial, J., Tartiere, L., Terrier De La Chaise, A., Thiercelin, M. C., Thomas, D., Thomas, M., Toko, L., Tournoux, F., Tristan, A., Trouillet, J. L., Tual, L., Vahanian, A., Verdier, F., Vernet Garnier, V., Vidal, Valentina, Weyne, P., Wolff, M., Wynckel, A., Zannad, N., Zinzius, P. Y., Marqueurs pronostiques et facteurs de régulations des pathologies cardiaques et vasculaires - UFC ( PCVP / CARDIO ), Université Bourgogne Franche-Comté ( UBFC ) -Université de Franche-Comté ( UFC ) -Centre Hospitalier Régional Universitaire [Besançon] ( CHRU Besançon ), Hospices Civils de Lyon ( HCL ), Infection, Antimicrobiens, Modélisation, Evolution ( IAME ), Université Paris Diderot - Paris 7 ( UPD7 ) -Université Paris 13 ( UP13 ) -Université Sorbonne Paris Cité ( USPC ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ), CIC Bichat ( CIC1425 ), Assistance publique - Hôpitaux de Paris (AP-HP)-Institut National de la Santé et de la Recherche Médicale ( INSERM ), Assistance publique - Hôpitaux de Paris (AP-HP)-AP-HP - Hôpital Bichat - Claude Bernard [Paris], Risques, maladies chroniques et société : des systèmes biologiques aux populations, Université Henri Poincaré - Nancy 1 ( UHP ), Centre Hospitalier Régional Universitaire [Besançon] ( CHRU Besançon ) -Hôpital Jean Minjoz, Centre Hospitalier Régional Universitaire de Nancy ( CHRU Nancy ), Recherches Translationnelles sur le VIH et les maladies infectieuses ( TransVIHMI ), Université Montpellier 1 ( UM1 ) -Université Cheikh Anta Diop ( UCAD ) -Universtié Yaoundé 1 (Cameroun)-Université de Montpellier ( UM ), Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre Hospitalier Régional Universitaire de Besançon (CHRU Besançon), and Université Cheikh Anta Diop [Dakar, Sénégal] (UCAD)-Institut de Recherche pour le Développement (IRD)-Université de Yaoundé I-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)

Subjects
Male, Time Factors, [SDV]Life Sciences [q-bio], Infective endocarditi, 030204 cardiovascular system & hematology, Logistic regression, 0302 clinical medicine, Risk Factors, pulmonary hypertension, Odds Ratio, Cardiac valvular surgery, Hospital Mortality, Prospective Studies, 030212 general & internal medicine, Treatment outcome, ComputingMilieux_MISCELLANEOUS, Original Research, Cardiovascular Surgery, Framingham Risk Score, Endocarditis, [ SDV.SPEE ] Life Sciences [q-bio]/Santé publique et épidémiologie, Middle Aged, Critical care, Infective endocarditis, Mortality, Predictors, Pulmonary hypertension, Quality control, Cardiology and Cardiovascular Medicine, Cardiac surgery, Europe, Treatment Outcome, Area Under Curve, Female, Mortality/Survival, medicine.medical_specialty, Renal function, Risk Assessment, Decision Support Techniques, 03 medical and health sciences, Predictive Value of Tests, medicine, Humans, Infectious Endocarditis, quality control, Cardiac Surgical Procedures, Risk factor, Aged, Chi-Square Distribution, Receiver operating characteristic, infective endocarditis, business.industry, Odds ratio, cardiac valvular surgery, medicine.disease, mortality, Surgery, critical care, predictors, Logistic Models, ROC Curve, [SDV.SPEE] Life Sciences [q-bio]/Santé publique et épidémiologie, Valvular Heart Disease, Multivariate Analysis, [SDV.SPEE]Life Sciences [q-bio]/Santé publique et épidémiologie, business, Predictor
Abstract

Background Aspecific scoring systems are used to predict the risk of death postsurgery in patients with infective endocarditis ( IE ). The purpose of the present study was both to analyze the risk factors for in‐hospital death, which complicates surgery for IE , and to create a mortality risk score based on the results of this analysis. Methods and Results Outcomes of 361 consecutive patients (mean age, 59.1±15.4 years) who had undergone surgery for IE in 8 European centers of cardiac surgery were recorded prospectively, and a risk factor analysis (multivariable logistic regression) for in‐hospital death was performed. The discriminatory power of a new predictive scoring system was assessed with the receiver operating characteristic curve analysis. Score validation procedures were carried out. Fifty‐six (15.5%) patients died postsurgery. BMI >27 kg/m 2 (odds ratio [ OR ], 1.79; P =0.049), estimated glomerular filtration rate OR , 3.52; P IV ( OR , 2.11; P =0.024), systolic pulmonary artery pressure >55 mm Hg ( OR , 1.78; P =0.032), and critical state ( OR , 2.37; P =0.017) were independent predictors of in‐hospital death. A scoring system was devised to predict in‐hospital death postsurgery for IE (area under the receiver operating characteristic curve, 0.780; 95% CI, 0.734–0.822). The score performed better than 5 of 6 scoring systems for in‐hospital death after cardiac surgery that were considered. Conclusions A simple scoring system based on risk factors for in‐hospital death was specifically created to predict mortality risk postsurgery in patients with IE .

Published
2017
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32. Mixed-State Specific Heat of the Type-II Superconductor Nb0.77Zr0.23 in Magnetic Fields up to B c2

Author

Mirmefstein, A., junod, A., Walker, E., Revaz, B., Genoud, J., and Triscone, G.

Abstract

In order to document the behavior of the mean-field mixed-state specific heat of an isotropic. strongly type-II superconductor (i.e., with a large value of the Ginzburg parameterk), and to provide a basis for comparison with high-temperature superconductors, we measured the specific heatC of the alloy Nb0.77Zr0.23 withT c = 10.8K, B c2 (0) = 7.9T, in magnetic fieldsB = 0, 0.2, 1.0, 12, 2.0, 2.4. 3.0, 3.3. 4.0. 4.4, 4.8, 5.2, 6.0. 6.6, 7.2 and 10 T. The values of the upper critical fieldB c2 ( T), thermodynamic critical fieldB c (T), Ginzburg parameterk(T), and coefficient γ(B) = limT0(C(T. B)/T) are derived from the specific heat data and found to be in agreement with the GLAG theory in the dirty limit. The behavior of the mixed-state specific heat is analyzed in terms ofC el /T,∂(C el /T)/∂B, and∂(C el /T)/∂T vs. Tcurves, whereC el is the electronic contribution to the specific heat

Published
2018

34. Recent experiments with the European 1 MW, 170 GHz industrial CW and modular SP prototype gyrotron for ITER

Author

Ioannidis, Z. C., Rzesnicki, T., Avramidis, K., Gantenbein, Gerd, Illy, Stefan, Jelonnek, John, Jin, J., Pagonakis, I. Gr., Schmid, M., Thumm, Manfred, Zein, A., Hermann, V., Legrand, F., Kasparek, W., Lechte, C., Alberti, S., Genoud, J., Hogge, J. P., Schlatter, C., Tran, M. Q., Chelis, J., Latsas, G. P., Tigelis, I. G., Zisis, A., Bruschi, A., Bin, W., Fanale, F., Albajar, F., Bonicelli, T., and Sanchez, F.

Subjects
Technology, ddc:600
Published
2018

36. High-efficiency, long-pulse operation of MW-level dual-frequency gyrotron, 84/126GHz, for the TCV Tokamak

Author

Alberti, S., primary, Hogge, J. P., additional, Isoz, P.-F., additional, Lavanchy, P., additional, Legrand, F., additional, Marletaz, B., additional, Masur, J., additional, Moro, A., additional, Pagonakis, I. Gr., additional, Silva, M., additional, Siravo, U., additional, Avramidis, K. A., additional, Toussaint, M., additional, Bin, W., additional, Bertinetti, A., additional, Dubray, J., additional, Fasel, D., additional, Garavaglia, S., additional, Genoud, J., additional, and Goodman, T., additional

Published
2019
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37. Novel linear analysis for a gyrotron oscillator based on a spectral approach

Author

Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology. Department of Physics, Massachusetts Institute of Technology. Plasma Science and Fusion Center, Tax, David Samuel, Guss, William C, Temkin, Richard J, Genoud, J., Tran, T. M., Alberti, S., Braunmueller, F., Hogge, J.-Ph., Tran, M. Q., Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology. Department of Physics, Massachusetts Institute of Technology. Plasma Science and Fusion Center, Tax, David Samuel, Guss, William C, Temkin, Richard J, Genoud, J., Tran, T. M., Alberti, S., Braunmueller, F., Hogge, J.-Ph., and Tran, M. Q.

Abstract

With the aim of gaining a better physical insight into linear regimes in gyrotrons, a new linear model was developed. This model is based on a spectral approach for solving the self-consistent system of equations describing the wave-particle interaction in the cavity of a gyrotron oscillator. Taking into account the wall-losses self-consistently and including the main system inhomogeneities in the cavity geometry and in the magnetic field, the model is appropriate to consider real system parameters. The main advantage of the spectral approach, compared with a time-dependent approach, is the possibility to describe all of the stable and unstable modes, respectively, with negative and positive growth rates. This permits to reveal the existence of a new set of eigenmodes, in addition to the usual eigenmodes issued from cold-cavity modes. The proposed model can be used for studying other instabilities such as, for instance, backward waves potentially excited in gyrotron beam tunnels., United States. Department of Energy. Office of Fusion Energy Sciences (Grant DE-FC02-93ER54186)

Published
2018

42. Progress of The Experiments With the European 1Mw, 170Ghz Industrial Cw Prototype Gyrotron For Iter

Author

Ioannidis, Z. C., primary, Rzesnicki, T., additional, Avramidis, K., additional, Gantenbein, G., additional, Illy, S., additional, Jin, J., additional, Kobarg, T., additional, Pagonakis, I. Gr., additional, Schmid, M., additional, Thumm, M., additional, Zein, A., additional, Jelonnek, J., additional, Alberti, S., additional, Braunmueller, F., additional, Hogge, J. -P., additional, Schlatter, C., additional, Genoud, J., additional, Tran, M. Q., additional, Kasparek, W., additional, Lechte, C., additional, Chelis, J., additional, Latsas, G. P., additional, Zisis, A., additional, Tigelis, I. G., additional, Bruschi, A., additional, Bin, W., additional, Lontano, M., additional, Hermann, V., additional, Rozier, Y., additional, Legrand, F., additional, Albajar, F., additional, Bonicelli, T., additional, and Frigot, P. -E., additional

Published
2017
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43. First CW experiments with the EU ITER 1 MW, 170 GHz industrial prototype gyrotron

Author

Ioannidis, Z. C., primary, Rzesnicki, T., additional, Avramidis, K., additional, Gantenbein, G., additional, Illy, S., additional, Jin, J., additional, Kobarg, T., additional, Pagonakis, I. Gr., additional, Schmid, M., additional, Thumm, M., additional, Jelonnek, J., additional, Hermann, V., additional, Rozier, Y., additional, Legrand, F., additional, Alberti, S., additional, Braunmueller, F., additional, Hogge, J.-P., additional, Schlatter, C., additional, Genoud, J., additional, Tran, M. Q., additional, Kasparek, W., additional, Lechte, C., additional, Vomvoridis, J. L., additional, Chelis, J., additional, Latsas, G. P., additional, Zisis, A., additional, Tigelis, I. G., additional, Bruschi, A., additional, Bin, W., additional, Lontano, M., additional, Albajar, F., additional, Bonicelli, T., additional, and Frigot, P.-E., additional

Published
2017
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44. The science program of the TCV tokamak: exploring fusion reactor and power plant concepts

Author

Coda, S., Albanese, R., Alberti, S., Ambrosino, R., Anand, H., Andrebe, Y., Ariola, M., Barton, J. E., Behn, R., Blanchard, P., Boedo, J. A., Bortolon, A., Braunmüller, F. H., Brémond, S., Brunner, S., Camenen, Y., Canal, G. P., Cooper, W. A., Cruz, N., De Baar, M., Decker, J., De Meijere, C. A., Duval, B. P., Fasoli, A., Federspiel, L., Felici, F., Fontana, M., Furno, I., Galperti, C., Garrido, I., Genoud, J., Goodman, T. P., Graves, J. P., Hennequin, P., Hogge, J. -Ph., Hommen, G., Huang, Z., Joye, B., Kamleitner, J., Karpushov, A., Kim, D., Kirneva, N., Krämer-Flecken, A., Labit, B., Lazzaro, E., Le, H. B., Lefevre, L., Li, F., Lipschultz, B., Lister, J. B., Llobet, X., Lunt, T., Malygin, A., Maljaars, E., Marini, C., Martin, Y., Mattei, M., Merle, A., Molina Cabrera, P. A., Moreau, D., Moret, J. -M., Morgan, T., Mustafin, N. A., Nespoli, F., Nouailletas, R., Nowak, S., Peysson, Y., Pironti, A., Pochelon, A., Porte, L., Reimerdes, H., Sauter, O., Schlatter, Ch., Schuster, E., Silva, M., Sinha, J., Stoltzfus-Dueck, T., Tál, B., Teplukhina, A. A., Testa, D., Theiler, C., Tonetti, G., Tran, M. Q., Tsui, C., Vermare, L., Vernay, T., Vijvers, W. A. J., Vu, N. M. T., Vuille, V., Weisen, H., Wenninger, R., Witrant, E., 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 (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Coda, S., Albanese, R., Alberti, S., Ambrosino, R., Anand, H., Andrebe, Y., Ariola, M., Barton, J. E., Behn, R., Blanchard, P., Boedo, J. A., Bortolon, A., Braunmüller, F. H., Brémond, S., Brunner, S., Camenen, Y., Canal, G. P., Cooper, W. A., Cruz, N., De Baar, M., Decker, J., De Meijere, C. A., Duval, B. P., Fasoli, A., Federspiel, L., Felici, F., Fontana, M., Furno, I., Galperti, C., Garrido, I., Genoud, J., Goodman, T. P., Graves, J. P., Hennequin, P., Hogge, J. -Ph., Hommen, G., Huang, Z., Joye, B., Kamleitner, J., Karpushov, A., Kim, D., Kirneva, N., Krämer-Flecken, A., Labit, B., Lazzaro, E., Le, H. B., Lefevre, L., Li, F., Lipschultz, B., Lister, J. B., Llobet, X., Lunt, T., Malygin, A., Maljaars, E., Marini, C., Martin, Y., Mattei, M., Merle, A., Molina Cabrera, P. A., Moreau, D., Moret, J. -M., Morgan, T., Mustafin, N. A., Nespoli, F., Nouailletas, R., Nowak, S., Peysson, Y., Pironti, A., Pochelon, A., Porte, L., Reimerdes, H., Sauter, O., Schlatter, Ch., Schuster, E., Silva, M., Sinha, J., Stoltzfus-Dueck, T., Tál, B., Teplukhina, A. A., Testa, D., Theiler, C., Tonetti, G., Tran, M. Q., Tsui, C., Vermare, L., Vernay, T., Vijvers, W. A. J., Vu, N. M. T., Vuille, V., Weisen, H., Wenninger, R., Witrant, E., Hogge, J. P. h., Krämer Flecken, A., Mattei, Massimiliano, Moret, J. M., Schlatter, C. h., Stoltzfus Dueck, T., and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)

Subjects
Nuclear and High Energy Physics, Tokamak, DEMO, ITER, nuclear fusion, plasma, TCV, tokamak, Condensed Matter Physics, Cyclotron, Condensed Matter Physic, 7. Clean energy, Electron cyclotron resonance, law.invention, [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], Physics::Plasma Physics, law, Physics, Toroid, Divertor, Plasma, Fusion power, Computational physics, Heat flux, Atomic physics
Abstract

International audience; TCV is acquiring a new 1 MW neutral beam and 2 MW additional third-harmonic electron cyclotron resonance heating (ECRH) to expand its operational range. Its existing shaping and ECRH launching versatility was amply exploited in an eclectic 2013 campaign. A new sub-ms real-time equilibrium reconstruction code was used in ECRH control of NTMs and in a prototype shape controller. The detection of visible light from the plasma boundary was also successfully used in a position-control algorithm. A new bang-bang controller improved stability against vertical displacements. The RAPTOR real-time transport simulator was employed to control the current density profile using electron cyclotron current drive. Shot-by-shot internal inductance optimization was demonstrated by iterative learning control of the current reference trace. Systematic studies of suprathermal electrons and ions in the presence of ECRH were performed. The L?H threshold power was measured to be ?50?75% higher in both H and He than D, to increase with the length of the outer separatrix, and to be independent of the current ramp rate. Core turbulence was found to decrease from positive to negative edge triangularity deep into the core. The geodesic acoustic mode was studied with multiple diagnostics, and its axisymmetry was confirmed by a full toroidal mapping of its magnetic component. A new theory predicting a toroidal rotation component at the plasma edge, driven by inhomogeneous transport and geodesic curvature, was tested successfully. A new high-confinement mode (IN-mode) was found with an edge barrier in density but not in temperature. The edge gradients were found to govern the scaling of confinement with current, power, density and triangularity. The dynamical interplay of confinement and magnetohydrodynamic modes leading to the density limit in TCV was documented. The heat flux profile decay lengths and heat load profile on the wall were documented in limited plasmas. In the snowflake (SF) divertor configuration the heat flux profiles were documented on all four strike points. SF simulations with the EMC3-EIRENE code, including the physics of the secondary separatrix, underestimate the flux to the secondary strike points, possibly resulting from steady-state E × B drifts. With neon injection, radiation in a SF was 15% higher than in a conventional divertor. The novel triple-null and X-divertor configurations were also achieved in TCV.

Published
2015
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45. Progress on the upgrade of the TCV EC-system with two 1MW dual-frequency gyrotrons

Author

Alberti, S., primary, Genoud, J., additional, Goodman, T., additional, Hogge, J.-P., additional, Silva, M., additional, Tran, T. M., additional, Tran, M. Q., additional, Avramidis, K., additional, Pagonakis, I. Gr., additional, Jin, J., additional, Illy, S., additional, Gantenbein, G., additional, Jelonnek, J., additional, Thumm, M., additional, Bin, W., additional, Garavaglia, S., additional, Moro, A., additional, Hermann, V., additional, Legrand, F., additional, and Rozier, Y., additional

Published
2016
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48. Pseudogap Precursor of the Superconducting Gap in Under- and Overdoped Bi2Sr2CaCu2O8+δ

Author

Renner, Ch., Revaz, B., Genoud, J.-Y., Kadowaki, K., and Fischer, Ø.

Subjects
ComputingMethodologies_DOCUMENTANDTEXTPROCESSING
Abstract

application/pdf, We present tunneling spectroscopy of Bi2Sr2CaCu2O8+δ single crystals as a function of oxygen doping and temperature. The doping dependence amounts essentially to an energy scaling of the tunneling spectra, with a quasiparticle gap that is reduced with increasing oxygen concentration. This superconducting gap is temperature independent up to the superconducting transition where the superconducting spectra merge continuously into another gaplike feature at the Fermi level. This pseudogap is found to be present both in underdoped and overdoped samples, and it scales with the superconducting gap.

Published
1998

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