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1. Experimental Runaway Electron Current Estimation in COMPASS Tokamak

Author: Milos Vlainic, Ondrej Ficker, Jan Mlynar, Eva Macusova, and the COMPASS Tokamak Team
Subjects: runway electron, plasma current, fusion plasma, tokamak, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract: Runaway electrons present a potential threat to the safe operation of future nuclear fusion large facilities based on the tokamak principle (e.g., ITER). The article presents an implementation of runaway electron current estimations at COMPASS tokamak. The method uses a theoretical method developed by Fujita et al., with the difference in using experimental measurements from EFIT and Thomson scattering. The procedure was explained on the COMPASS discharge number 7298, which has a significant runaway electron population. Here, it was found that at least 4 kA of the plasma current is driven by the runaway electrons. Next, the method aws used on the set of plasma discharges with the variable electron plasma density. The difference in the plasma current was explained by runaway electrons, and their current was estimated using the aforementioned method. The experimental results are compared with the theory and simulation. The comparison presented some disagreements, showing the possible direction for the code development. Additional application on runaway electron energy limit is also addressed.
Published: 2019
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2. Dependence on plasma shape and plasma fueling for small edge-localized mode regimes in TCV and ASDEX Upgrade

Author: V. Piergotti, F. Pesamosca, Bogdan Hnat, A. Sperduti, A. Krivska, J. Vicente, Panagiotis Tolias, Emanuele Poli, Matthias Hoelzl, Benedikt Geiger, A. Jardin, J. Ayllon-Guerola, G. Apruzzese, T. Lunt, J. Galdon-Quiroga, Riccardo Maggiora, M. Tardocchi, M. Koubiti, T. Jonsson, Bruce Lipschultz, P. Innocente, A. Gude, I Miron, M. G. Dunne, G. F. Harrer, A. Moro, A. Iantchenko, K. Galazka, P. Poloskei, K. Bogar, Roberto Ambrosino, G. Ferr, Vladimir E. Moiseenko, Istvan Cziegler, L. Guimarais, S. Vartanian, B. Erds, G. Pucella, V. Bobkov, James Buchanan, Raffaele Albanese, Harry M. Meyer, D. Boeyaert, G. F. Matthews, Eva Macusova, V. S. Marchenko, R. Zagórski, J. Buermans, A. Fil, W. Zhang, Giuseppe Gorini, B. Tal, D. Zaloga, Hugo Bufferand, A. Romano, L. Colas, J. Zebrowski, M. Weiland, L. Barrera-Orte, Matjaž Panjan, A.J. Thornton, E. Wolfrum, Miglena Dimitrova, R. M. McDermott, R. Lombroni, O. Tudisco, F. Reimold, E. R. Solano, X. Feng, Petra Bilkova, M. Groth, E. Alessi, D. S. Gahle, Olivier Février, I. Voitsekhovitch, Matthew Carr, A. Bock, O. Vasilovici, C. Ham, Lorenzo Figini, Guglielmo Rubinacci, Peter Lang, Pierre Manas, S. Costea, A. Kirk, F. Causa, J. Adamek, Vu N. M. T., M. Cavedon, O. Grover, Geert Verdoolaege, M. Spolaore, L. Sanchis-Sanchez, P. Bohm, P. V. Kazantzidis, Sarah Newton, M. Tomes, M.-L. Mayoral, J. R. Harrison, C. Mazzotta, H. Reimerdes, Jorge Morales, D. Brunetti, J. Gonzalez-Martin, Tomas Markovic, S. S. Henderson, D. Ricci, J. Juul Rasmussen, F. Janky, S. Saarelma, Z. Popovic, C. Tsironis, J. J. Rasmussen, S. K. Hansen, Sandra C. Chapman, Volker Naulin, H. Arnichand, Roberto Paccagnella, M. Faitsch, Anders Nielsen, M. Kong, V. Igochine, C. Piron, C. Bowman, Jorge Ferreira, D. Sytnykov, K. G. McClements, Olivier Sauter, Ondrej Ficker, Matthias Wiesenberger, T. Ravensbergen, C. Reux, Irena Ivanova-Stanik, Dirk Reiser, M. Bernert, M. Vallar, J-M Moret, M. Gruca, D. I. Refy, P. Cano Megias, Benoit Labit, M. Schubert, Giuliana Sias, O. Bogar, P. J. Mc Carthy, I. Faust, Gergely Papp, F. Matos, J. Garcia, C. Marini, E. L. Sorokovoy, Dimitri Voltolina, George Wilkie, J. M. Santos, R. R. Sheeba, Vladimir Weinzettl, Sergei Kasilov, J. Cerovsky, Matteo Agostini, G. Tardini, Laurie Porte, F. Dolizy, L. Gil, Matthias Komm, A. Dal Molin, B. Sieglin, Roch Kwiatkowski, M. C. C Messmer, Toke Koldborg Jensen, Vinodh Bandaru, Ben F. McMillan, Alessandra Fanni, Daniele Carnevale, Shimpei Futatani, D. P. Coster, V. Korovin, S. E. Sharapov, Patrik Ollus, J. Gath, A. Czarnecka, D. Gallart, M. Peterka, P. Vallejos Olivares, Jernej Kovacic, Nicolas Fedorczak, Silvio Ceccuzzi, L. Piron, J. Rosato, G. Kocsis, Stefan Kragh Nielsen, M. Garcia-Mu oz, Radomir Panek, S. F. Smith, Paolo Bettini, A. Mariani, R. Dejarnac, Lorenzo Frassinetti, D. Douai, L. Garzotti, H. J. Sun, C.K. Tsui, N. den Harder, John Elmerdahl Olsen, F. Bombarda, M. Francesco, Piero Martin, D. Hogeweij, P. Blanchard, F. Bouquey, Gabor Por, Luca Boncagni, Carlo Sozzi, Martin Hron, P. A. Schneider, V. P. Loschiavo, David Terranova, D. Aguiam, D. Choi, M. Gobbin, D. Iglesias, M. Reich, G. Avdeeva, A. Gallo, O. Biletskyi, M. Aradi, F. Liu, M. Griener, Antti Snicker, L. Kripner, Jérôme Bucalossi, L. Hesslow, Nick Walkden, M. Rodriguez-Ramos, T. C. Blanken, Cristian Galperti, F. Jaulmes, G. Calabr, G.A. Rattá, W. Bin, S. Garavaglia, V. Plyusnin, Andreas Frank Martitsch, A. Zisis, Rita Lorenzini, Duccio Testa, M. Passeri, Ola Embréus, N. Krawczyk, K. Särkimäki, Davide Galassi, D. Samaddar, M. Oberkofler, E. Seliunin, D. Brida, P. Buratti, F. Nabais, J. Ongena, J. Likonen, Yann Camenen, M. J. Mantsinen, F. Carpanese, S. Wiesen, P. Piovesan, Mirko Salewski, J. Hawke, Florian Laggner, R. Bilato, M. Wischmeier, L. Pigatto, G. I. Pokol, G. Giruzzi, Jens Madsen, D. Gadariya, L. Stipani, Christian Theiler, J. Stober, Michael Barnes, Timothy Goodman, R. D. Nem, J. J. Dominguez-Palacios Duran, F. Militello, Y. Kulyk, D. J. Cruz Zabala, A. Drenik, P. Manz, M. Scheffer, V. Pericoli Radolfini, B. Tilia, John Omotani, B. Vanovac, B. S. Schneider, E. Fable, Jakub Urban, T. Gyergyek, A. N. Karpushov, M. Farnik, Jakub Seidl, Christopher G. Albert, Antoine Merle, A. Cathey, D. A. Ryan, Sergio Galeani, R. Scannell, A. Havranek, G. de Carolis, C. Soria-Hoyo, S. Gibson, D. Carralero, D. Meshcheriakov, Morten Stejner, B. P. Duval, Francesco Cordella, Mitja Kelemen, Svetlana V. Ratynskaia, Stefano Coda, L. Calacci, C. Cianfarani, Faa Federico Felici, A. C. A. Figueiredo, L. Panaccione, E. Viezzer, Fabio Villone, Daniele Milanesio, Winfried Kernbichler, Mario Sassano, A. Teplukhina, S. Zoletnik, L. Laguardia, P. Molina Cabrera, Taina Kurki-Suonio, D. Micheletti, P. Zanca, Daniel Dunai, S. Feng, J. Decker, Stylianos Varoutis, Lorella Carraro, M. Wensing, Gustavo Granucci, Artur Palha, A. Kappatou, J. Garcia-Lopez, Felix I. Parra, Ye. O. Kazakov, S. Brezinsek, Didier Mazon, A. Lahtinen, I. Paradela Perez, P. Chmielewski, L. Giacomelli, Alessandro Pau, Gianluca Spizzo, R. Delogu, R. J. Akers, H. De Oliveira, Petr Vondracek, F. P. Orsitto, J. Hobirk, L. Xiang, A. Burckhart, B. Maljaars, V. Petrzilka, Ocleto D'Arcangelo, P. David, D. Grekov, Tamás Szepesi, Y. Andr be, P. Hacek, M. Toscano-Jimenez, T. Pütterich, L. Cordaro, V. Nikolaeva, F. Orain, M. Rabinski, C. Ionita-Schrittwieser, T. Tala, Maria Ester Puiatti, A. Casolari, T. Happel, Pär Strand, Benjamin Daniel Dudson, P. Mantica, Z. Huang, D. Colette, G. Ciraolo, Jan Mlynar, W. Suttrop, C. Meineri, J. Horacek, Seppo Sipilä, M. Gospodarczyk, S. Mastrostefano, Jesús Vega, Antti Hakola, Kevin Verhaegh, Roman Schrittwieser, C. Marchetto, M. Willensdorfer, Jari Varje, D. C. van Vugt, J. Faustin, Mathias Hoppe, M. Dreval, A. Perek, C. Angioni, Laure Vermare, U. A. Sheikh, J. F. Rivero-Rodriguez, G. Rubino, S.N. Reznik, Tsv K Popov, S. Nowak, A. S. Jacobsen, J. R. Martin Solis, David Moulton, Heinz Isliker, K. Wu, Anna Salmi, F. Nespoli, S. Elmore, O. Kudlacek, A. Kallenbach, Rok Zaplotnik, D. L. Keeling, L. Giannone, M. Maraschek, Carlos B. da Silva, F. Hitzler, M. Valovic, M. W. Jakubowski, L. Gabellieri, Jozef Varju, Marco Cecconello, M. Valisa, Vlado Menkovski, Gábor Cseh, E. Thoren, T. Eich, R. Coelho, F. Bagnato, Matteo Zuin, Alexander Kendl, G. Rocchi, G. Pautasso, D. Naydenkova, R. O. Pavlichenko, M. Fontana, Lionello Marrelli, Tommaso Bolzonella, Nicola Vianello, Pascale Hennequin, R. Ochoukov, Tom Wauters, Christian Hopf, Ch. Fuchs, E. Giovannozzi, Fulvio Auriemma, Roberto Maurizio, Stefan Buller, Massimo Nocente, K. Krieger, G. Grenfell, N. Rispoli, R. Dux, Barbara Cannas, Laboratoire de Physique des Plasmas (LPP), Université Paris-Saclay-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École polytechnique (X)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Labit, B., Eich, T., Harrer, G. F., Wolfrum, E., Bernert, M., Dunne, M. G., Frassinetti, L., Hennequin, P., Maurizio, R., Merle, A., Meyer, H., Saarelma, S., Sheikh, U., Adamek, J., Agostini, M., Aguiam, D., Akers, R., Albanese, R., Albert, C., Alessi, E., Ambrosino, R., Andr be, Y., Angioni, C., Apruzzese, G., Aradi, M., Arnichand, H., Auriemma, F., Avdeeva, G., Ayllon-Guerola, J. M., Bagnato, F., Bandaru, V. K., Barnes, M., Barrera-Orte, L., Bettini, P., Bilato, R., Biletskyi, O., Bilkova, P., Bin, W., Blanchard, P., Blanken, T., Bobkov, V., Bock, A., Boeyaert, D., Bogar, K., Bogar, O., Bohm, P., Bolzonella, T., Bombarda, F., Boncagni, L., Bouquey, F., Bowman, C., Brezinsek, S., Brida, D., Brunetti, D., Bucalossi, J., Buchanan, J., Buermans, J., Bufferand, H., Buller, S., Buratti, P., Burckhart, A., Calabr, G., Calacci, L., Camenen, Y., Cannas, B., Cano Megias, P., Carnevale, D., Carpanese, F., Carr, M., Carralero, D., Carraro, L., Casolari, A., Cathey, A., Causa, F., Cavedon, M., Cecconello, M., Ceccuzzi, S., Cerovsky, J., Chapman, S., Chmielewski, P., Choi, D., Cianfarani, C., Ciraolo, G., Coda, S., Coelho, R., Colas, L., Colette, D., Cordaro, L., Cordella, F., Costea, S., Coster, D., Cruz Zabala, D. J., Cseh, G., Czarnecka, A., Cziegler, I., D'Arcangelo, O., Dal Molin, A., David, P., De Carolis, G., De Oliveira, H., Decker, J., Dejarnac, R., Delogu, R., Den Harder, N., Dimitrova, M., Dolizy, F., Dominguez-Palacios Duran, J. J., Douai, D., Drenik, A., Dreval, M., Dudson, B., Dunai, D., Duval, B. P., Dux, R., Elmore, S., Embreus, O., Erds, B., Fable, E., Faitsch, M., Fanni, A., Farnik, M., Faust, I., Faustin, J., Fedorczak, N., Felici, F., Feng, S., Feng, X., Ferreira, J., Ferr, G., Fevrier, O., Ficker, O., Figini, L., Figueiredo, A., Fil, A., Fontana, M., Francesco, M., Fuchs, C., Futatani, S., Gabellieri, L., Gadariya, D., Gahle, D., Galassi, D., Galazka, K., Galdon-Quiroga, J., Galeani, S., Gallart, D., Gallo, A., Galperti, C., Garavaglia, S., Garcia, J., Garcia-Lopez, J., Garcia-Mu oz, M., Garzotti, L., Gath, J., Geiger, B., Giacomelli, L., Giannone, L., Gibson, S., Gil, L., Giovannozzi, E., Giruzzi, G., Gobbin, M., Gonzalez-Martin, J., Goodman, T. P., Gorini, G., Gospodarczyk, M., Granucci, G., Grekov, D., Grenfell, G., Griener, M., Groth, M., Grover, O., Gruca, M., Gude, A., Guimarais, L., Gyergyek, T., Hacek, P., Hakola, A., Ham, C., Happel, T., Harrison, J., Havranek, A., Hawke, J., Henderson, S., Hesslow, L., Hitzler, F., Hnat, B., Hobirk, J., Hoelzl, M., Hogeweij, D., Hopf, C., Hoppe, M., Horacek, J., Hron, M., Huang, Z., Iantchenko, A., Iglesias, D., Igochine, V., Innocente, P., Ionita-Schrittwieser, C., Isliker, H., Ivanova-Stanik, I., Jacobsen, A., Jakubowski, M., Janky, F., Jardin, A., Jaulmes, F., Jensen, T., Jonsson, T., Kallenbach, A., Kappatou, A., Karpushov, A., Kasilov, S., Kazakov, Y., Kazantzidis, P. V., Keeling, D., Kelemen, M., Kendl, A., Kernbichler, W., Kirk, A., Kocsis, G., Komm, M., Kong, M., Korovin, V., Koubiti, M., Kovacic, J., Krawczyk, N., Krieger, K., Kripner, L., Krivska, A., Kudlacek, O., Kulyk, Y., Kurki-Suonio, T., Kwiatkowski, R., Laggner, F., Laguardia, L., Lahtinen, A., Lang, P., Likonen, J., Lipschultz, B., Liu, F., Lombroni, R., Lorenzini, R., Loschiavo, V. P., Lunt, T., Macusova, E., Madsen, J., Maggiora, R., Maljaars, B., Manas, P., Mantica, P., Mantsinen, M. J., Manz, P., Maraschek, M., Marchenko, V., Marchetto, C., Mariani, A., Marini, C., Markovic, T., Marrelli, L., Martin, P., Martin Solis, J. R., Martitsch, A., Mastrostefano, S., Matos, F., Matthews, G., Mayoral, M. -L., Mazon, D., Mazzotta, C., Mc Carthy, P., Mcclements, K., Mcdermott, R., Mcmillan, B., Meineri, C., Menkovski, V., Meshcheriakov, D., Messmer, M., Micheletti, D., Milanesio, D., Militello, F., Miron, I. G., Mlynar, J., Moiseenko, V., Molina Cabrera, P. A., Morales, J., Moret, J. -M., Moro, A., Moulton, D., Nabais, F., Naulin, V., Naydenkova, D., Nem, R. D., Nespoli, F., Newton, S., Nielsen, A. H., Nielsen, S. K., Nikolaeva, V., Nocente, M., Nowak, S., Oberkofler, M., Ochoukov, R., Ollus, P., Olsen, J., Omotani, J., Ongena, J., Orain, F., Orsitto, F. P., Paccagnella, R., Palha, A., Panaccione, L., Panek, R., Panjan, M., Papp, G., Paradela Perez, I., Parra, F., Passeri, M., Pau, A., Pautasso, G., Pavlichenko, R., Perek, A., Pericoli Radolfini, V., Pesamosca, F., Peterka, M., Petrzilka, V., Piergotti, V., Pigatto, L., Piovesan, P., Piron, C., Piron, L., Plyusnin, V., Pokol, G., Poli, E., Poloskei, P., Popov, T., Popovic, Z., Por, G., Porte, L., Pucella, G., Puiatti, M. E., Putterich, T., Rabinski, M., Juul Rasmussen, J., Rasmussen, J., Ratta, G. A., Ratynskaia, S., Ravensbergen, T., Refy, D., Reich, M., Reimerdes, H., Reimold, F., Reiser, D., Reux, C., Reznik, S., Ricci, D., Rispoli, N., Rivero-Rodriguez, J. F., Rocchi, G., Rodriguez-Ramos, M., Romano, A., Rosato, J., Rubinacci, G., Rubino, G., Ryan, D. A., Salewski, M., Salmi, A., Samaddar, D., Sanchis-Sanchez, L., Santos, J., Sarkimaki, K., Sassano, M., Sauter, O., Scannell, R., Scheffer, M., Schneider, B. S., Schneider, P., Schrittwieser, R., Schubert, M., Seidl, J., Seliunin, E., Sharapov, S., Sheeba, R. R., Sias, G., Sieglin, B., Silva, C., Sipila, S., Smith, S., Snicker, A., Solano, E. R., Hansen, S. K., Soria-Hoyo, C., Sorokovoy, E., Sozzi, C., Sperduti, A., Spizzo, G., Spolaore, M., Stejner, M., Stipani, L., Stober, J., Strand, P., Sun, H., Suttrop, W., Sytnykov, D., Szepesi, T., Tal, B., Tala, T., Tardini, G., Tardocchi, M., Teplukhina, A., Terranova, D., Testa, D., Theiler, C., Thoren, E., Thornton, A., Tilia, B., Tolias, P., Tomes, M., Toscano-Jimenez, M., Tsironis, C., Tsui, C., Tudisco, O., Urban, J., Valisa, M., Vallar, M., Vallejos Olivares, P., Valovic, M., Van Vugt, D., Vanovac, B., Varje, J., Varju, J., Varoutis, S., Vartanian, S., Vasilovici, O., Vega, J., Verdoolaege, G., Verhaegh, K., Vermare, L., Vianello, N., Vicente, J., Viezzer, E., Villone, F., Voitsekhovitch, I., Voltolina, D., Vondracek, P., Vu, N. M. T., Walkden, N., Wauters, T., Weiland, M., Weinzettl, V., Wensing, M., Wiesen, S., Wiesenberger, M., Wilkie, G., Willensdorfer, M., Wischmeier, M., Wu, K., Xiang, L., Zagorski, R., Zaloga, D., Zanca, P., Zaplotnik, R., Zebrowski, J., Zhang, W., Zisis, A., Zoletnik, S., Zuin, M., Swiss Federal Institute of Technology Lausanne, Max-Planck-Institut für Plasmaphysik, Vienna University of Technology, KTH Royal Institute of Technology, Université Paris-Saclay, JET, Czech Academy of Sciences, National Research Council of Italy, University of Lisbon, University of Naples Federico II, Graz University of Technology, University of Naples Parthenope, Agenzia nazionale per le nuove tecnologie, l'energia e lo sviluppo economico sostenibile, Danmarks Tekniske Universitet, University of Seville, University of Oxford, EUROfusion Programme Management Unit, National Science Center Kharkov Institute of Physics and Technology, Eindhoven University of Technology, Forschungszentrum Jülich, CEA, University of York, Royal Military Academy, Chalmers University of Technology, Tuscia University, Università di Roma Tor Vergata, CNRS, University of Cagliari, CIEMAT, Uppsala University, University of Warwick, Soltan Institute for Nuclear Studies, University of Innsbruck, Hungarian Academy of Sciences, Budapest University of Technology and Economics, Durham University, BarcelonaTech, University of Strathclyde, Barcelona Supercomputing Center, University of Milan - Bicocca, Karlsruhe Institute of Technology, Fusion and Plasma Physics, J. Stefan Institute, VTT Technical Research Centre of Finland, Dutch Institute for Fundamental Energy Research, Aristotle University of Thessaloniki, National Technical University of Athens, National Centre for Nuclear Research, University of Helsinki, Université Côte d'Azur, Polytechnic University of Turin, NASU - Institute of Nuclear Research, University of Cassino and Southern Lazio, University College Cork, National Institute for Laser, Plasma and Radiation Physics, Department of Applied Physics, Sofia University St. Kliment Ohridski, Ghent University, Aalto-yliopisto, Aalto University, Labit, B, Eich, T, Harrer, G, Wolfrum, E, Bernert, M, Dunne, M, Frassinetti, L, Hennequin, P, Maurizio, R, Merle, A, Meyer, H, Saarelma, S, Sheikh, U, Adamek, J, Agostini, M, Aguiam, D, Akers, R, Albanese, R, Albert, C, Alessi, E, Ambrosino, R, Andr be, Y, Angioni, C, Apruzzese, G, Aradi, M, Arnichand, H, Auriemma, F, Avdeeva, G, Ayllon-Guerola, J, Bagnato, F, Bandaru, V, Barnes, M, Barrera-Orte, L, Bettini, P, Bilato, R, Biletskyi, O, Bilkova, P, Bin, W, Blanchard, P, Blanken, T, Bobkov, V, Bock, A, Boeyaert, D, Bogar, K, Bogar, O, Bohm, P, Bolzonella, T, Bombarda, F, Boncagni, L, Bouquey, F, Bowman, C, Brezinsek, S, Brida, D, Brunetti, D, Bucalossi, J, Buchanan, J, Buermans, J, Bufferand, H, Buller, S, Buratti, P, Burckhart, A, Calabr, G, Calacci, L, Camenen, Y, Cannas, B, Cano Megias, P, Carnevale, D, Carpanese, F, Carr, M, Carralero, D, Carraro, L, Casolari, A, Cathey, A, Causa, F, Cavedon, M, Cecconello, M, Ceccuzzi, S, Cerovsky, J, Chapman, S, Chmielewski, P, Choi, D, Cianfarani, C, Ciraolo, G, Coda, S, Coelho, R, Colas, L, Colette, D, Cordaro, L, Cordella, F, Costea, S, Coster, D, Cruz Zabala, D, Cseh, G, Czarnecka, A, Cziegler, I, D'Arcangelo, O, Dal Molin, A, David, P, De Carolis, G, De Oliveira, H, Decker, J, Dejarnac, R, Delogu, R, Den Harder, N, Dimitrova, M, Dolizy, F, Dominguez-Palacios Duran, J, Douai, D, Drenik, A, Dreval, M, Dudson, B, Dunai, D, Duval, B, Dux, R, Elmore, S, Embreus, O, Erds, B, Fable, E, Faitsch, M, Fanni, A, Farnik, M, Faust, I, Faustin, J, Fedorczak, N, Felici, F, Feng, S, Feng, X, Ferreira, J, Ferr, G, Fevrier, O, Ficker, O, Figini, L, Figueiredo, A, Fil, A, Fontana, M, Francesco, M, Fuchs, C, Futatani, S, Gabellieri, L, Gadariya, D, Gahle, D, Galassi, D, Galazka, K, Galdon-Quiroga, J, Galeani, S, Gallart, D, Gallo, A, Galperti, C, Garavaglia, S, Garcia, J, Garcia-Lopez, J, Garcia-Mu oz, M, Garzotti, L, Gath, J, Geiger, B, Giacomelli, L, Giannone, L, Gibson, S, Gil, L, Giovannozzi, E, Giruzzi, G, Gobbin, M, Gonzalez-Martin, J, Goodman, T, Gorini, G, Gospodarczyk, M, Granucci, G, Grekov, D, Grenfell, G, Griener, M, Groth, M, Grover, O, Gruca, M, Gude, A, Guimarais, L, Gyergyek, T, Hacek, P, Hakola, A, Ham, C, Happel, T, Harrison, J, Havranek, A, Hawke, J, Henderson, S, Hesslow, L, Hitzler, F, Hnat, B, Hobirk, J, Hoelzl, M, Hogeweij, D, Hopf, C, Hoppe, M, Horacek, J, Hron, M, Huang, Z, Iantchenko, A, Iglesias, D, Igochine, V, Innocente, P, Ionita-Schrittwieser, C, Isliker, H, Ivanova-Stanik, I, Jacobsen, A, Jakubowski, M, Janky, F, Jardin, A, Jaulmes, F, Jensen, T, Jonsson, T, Kallenbach, A, Kappatou, A, Karpushov, A, Kasilov, S, Kazakov, Y, Kazantzidis, P, Keeling, D, Kelemen, M, Kendl, A, Kernbichler, W, Kirk, A, Kocsis, G, Komm, M, Kong, M, Korovin, V, Koubiti, M, Kovacic, J, Krawczyk, N, Krieger, K, Kripner, L, Krivska, A, Kudlacek, O, Kulyk, Y, Kurki-Suonio, T, Kwiatkowski, R, Laggner, F, Laguardia, L, Lahtinen, A, Lang, P, Likonen, J, Lipschultz, B, Liu, F, Lombroni, R, Lorenzini, R, Loschiavo, V, Lunt, T, Macusova, E, Madsen, J, Maggiora, R, Maljaars, B, Manas, P, Mantica, P, Mantsinen, M, Manz, P, Maraschek, M, Marchenko, V, Marchetto, C, Mariani, A, Marini, C, Markovic, T, Marrelli, L, Martin, P, Martin Solis, J, Martitsch, A, Mastrostefano, S, Matos, F, Matthews, G, Mayoral, M, Mazon, D, Mazzotta, C, Mc Carthy, P, Mcclements, K, Mcdermott, R, Mcmillan, B, Meineri, C, Menkovski, V, Meshcheriakov, D, Messmer, M, Micheletti, D, Milanesio, D, Militello, F, Miron, I, Mlynar, J, Moiseenko, V, Molina Cabrera, P, Morales, J, Moret, J, Moro, A, Moulton, D, Nabais, F, Naulin, V, Naydenkova, D, Nem, R, Nespoli, F, Newton, S, Nielsen, A, Nielsen, S, Nikolaeva, V, Nocente, M, Nowak, S, Oberkofler, M, Ochoukov, R, Ollus, P, Olsen, J, Omotani, J, Ongena, J, Orain, F, Orsitto, F, Paccagnella, R, Palha, A, Panaccione, L, Panek, R, Panjan, M, Papp, G, Paradela Perez, I, Parra, F, Passeri, M, Pau, A, Pautasso, G, Pavlichenko, R, Perek, A, Pericoli Radolfini, V, Pesamosca, F, Peterka, M, Petrzilka, V, Piergotti, V, Pigatto, L, Piovesan, P, Piron, C, Piron, L, Plyusnin, V, Pokol, G, Poli, E, Poloskei, P, Popov, T, Popovic, Z, Por, G, Porte, L, Pucella, G, Puiatti, M, Putterich, T, Rabinski, M, Juul Rasmussen, J, Rasmussen, J, Ratta, G, Ratynskaia, S, Ravensbergen, T, Refy, D, Reich, M, Reimerdes, H, Reimold, F, Reiser, D, Reux, C, Reznik, S, Ricci, D, Rispoli, N, Rivero-Rodriguez, J, Rocchi, G, Rodriguez-Ramos, M, Romano, A, Rosato, J, Rubinacci, G, Rubino, G, Ryan, D, Salewski, M, Salmi, A, Samaddar, D, Sanchis-Sanchez, L, Santos, J, Sarkimaki, K, Sassano, M, Sauter, O, Scannell, R, Scheffer, M, Schneider, B, Schneider, P, Schrittwieser, R, Schubert, M, Seidl, J, Seliunin, E, Sharapov, S, Sheeba, R, Sias, G, Sieglin, B, Silva, C, Sipila, S, Smith, S, Snicker, A, Solano, E, Hansen, S, Soria-Hoyo, C, Sorokovoy, E, Sozzi, C, Sperduti, A, Spizzo, G, Spolaore, M, Stejner, M, Stipani, L, Stober, J, Strand, P, Sun, H, Suttrop, W, Sytnykov, D, Szepesi, T, Tal, B, Tala, T, Tardini, G, Tardocchi, M, Teplukhina, A, Terranova, D, Testa, D, Theiler, C, Thoren, E, Thornton, A, Tilia, B, Tolias, P, Tomes, M, Toscano-Jimenez, M, Tsironis, C, Tsui, C, Tudisco, O, Urban, J, Valisa, M, Vallar, M, Vallejos Olivares, P, Valovic, M, Van Vugt, D, Vanovac, B, Varje, J, Varju, J, Varoutis, S, Vartanian, S, Vasilovici, O, Vega, J, Verdoolaege, G, Verhaegh, K, Vermare, L, Vianello, N, Vicente, J, Viezzer, E, Villone, F, Voitsekhovitch, I, Voltolina, D, Vondracek, P, Vu, N, Walkden, N, Wauters, T, Weiland, M, Weinzettl, V, Wensing, M, Wiesen, S, Wiesenberger, M, Wilkie, G, Willensdorfer, M, Wischmeier, M, Wu, K, Xiang, L, Zagorski, R, Zaloga, D, Zanca, P, Zaplotnik, R, Zebrowski, J, Zhang, W, Zisis, A, Zoletnik, S, Zuin, M, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Control Systems Technology, Science and Technology of Nuclear Fusion, Data Mining, Sensorics for fusion reactors, and Magneto-Hydro-Dynamic Stability of Fusion Plasmas
Subjects: Nuclear and High Energy Physics, Settore ING-INF/04, Work package, grassy ELM, ballooning modes, Nuclear physics, 01 natural sciences, Flattening, Ballooning, 010305 fluids & plasmas, grassy ELMs, separatrix density, ASDEX Upgrade, [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], 0103 physical sciences, 010306 general physics, Edge-localized mode, QC, H-mode, plasma triangularity, type-II ELMs, Physics, Física [Àrees temàtiques de la UPC], type-II ELM, Plasma, Condensed Matter Physics, Null (physics), Shear (sheet metal), Física nuclear, Atomic physics, ballooning mode
Abstract: Within the EUROfusion MST1 work package, a series of experiments has been conducted on AUG and TCV devices to disentangle the role of plasma fueling and plasma shape for the onset of small ELM regimes. On both devices, small ELM regimes with high confinement are achieved if and only if two conditions are fulfilled at the same time. Firstly, the plasma density at the separatrix must be large enough (), leading to a pressure profile flattening at the separatrix, which stabilizes type-I ELMs. Secondly, the magnetic configuration has to be close to a double null (DN), leading to a reduction of the magnetic shear in the extreme vicinity of the separatrix. As a consequence, its stabilizing effect on ballooning modes is weakened. Peer Reviewed Article escrit per 365 autors/autores: Labit, B.; Eich, T.; Harrer, G. F.; Wolfrum, E.; Bernert, M.; Dunne, M. G.; Frassinetti, L.; Hennequin, P.; Maurizio, R.; Merle, A.; Meyer, H.; Saarelma, S.; Sheikh, U.; Adamek, J.; Agostini, M.; Aguiam, D.; Akers, R.; Albanese, R.; Albert, C.; Alessi, E.; Ambrosino, R.; Andr be, Y.; Angioni, C.; Apruzzese, G.; Aradi, M.; Arnichand, H.; Auriemma, F.; Avdeeva, G.; Ayllon-Guerola, J. M.; Bagnato, F.; Bandaru, V. K.; Barnes, M.; Barrera-Orte, L.; Bettini, P.; Bilato, R.; Biletskyi, O.; Bilkova, P.; Bin, W.; Blanchard, P.; Blanken, T.; Bobkov, V.; Bock, A.; Boeyaert, D.; Bogar, K.; Bogar, O.; Bohm, P.; Bolzonella, T.; Bombarda, F.; Boncagni, L.; Bouquey, F.; Bowman, C.; Brezinsek, S.; Brida, D.; Brunetti, D.; Bucalossi, J.; Buchanan, J.; Buermans, J.; Bufferand, H.; Buller, S.; Buratti, P.; Burckhart, A.; Calabr, G.; Calacci, L.; Camenen, Y.; Cannas, B.; Cano Megías, P.; Carnevale, D.; Carpanese, F.; Carr, M.; Carralero, D.; Carraro, L.; Casolari, A.; Cathey, A.; Causa, F.; Cavedon, M.; Cecconello, M.; Ceccuzzi, S.; Cerovsky, J.; Chapman, S.; Chmielewski, P.; Choi, D.; Cianfarani, C.; Ciraolo, G.; Coda, S.; Coelho, R.; Colas, L.; Colette, D.; Cordaro, L.; Cordella, F.; Costea, S.; Coster, D.; Cruz Zabala, D. J.; Cseh, G.; Czarnecka, A.; Cziegler, I.; D’Arcangelo, O.; Dal Molin, A.; David, P.; De Carolis, G.; De Oliveira, H.; Decker, J.; Dejarnac, R.; Delogu, R.; Den Harder, N.; Dimitrova, M.; Dolizy, F.; Domínguez-Palacios Durán, J. J.; Douai, D.; Drenik, A.; Dreval, M.; Dudson, B.; Dunai, D.; Duval, B. P.; Dux, R.; Elmore, S.; Embréus, O.; Erds, B.; Fable, E.; Faitsch, M.; Fanni, A.; Farnik, M.; Faust, I.; Faustin, J.; Fedorczak, N.; Felici, F.; Feng, S.; Feng, X.; Ferreira, J.; Ferr, G.; Février, O.; Ficker, O.; Figini, L.; Figueiredo, A.; Fil, A.; Fontana, M.; Francesco, M.; Fuchs, C.; Futatani, S.; Gabellieri, L.; Gadariya, D.; Gahle, D.; Galassi, D.; Gałązka, K.; Galdon-Quiroga, J.; Galeani, S.; Gallart, D.; Gallo, A.; Galperti, C.; Garavaglia, S.; Garcia, J.; Garcia-Lopez, J.; Garcia-Mu oz, M.; Garzotti, L.; Gath, J.; Geiger, B.; Giacomelli, L.; Giannone, L.; Gibson, S.; Gil, L.; Giovannozzi, E.; Giruzzi, G.; Gobbin, M.; Gonzalez-Martin, J.; Goodman, T. P.; Gorini, G.; Gospodarczyk, M.; Granucci, G.; Grekov, D. 1; Grenfell, G.; Griener, M.; Groth, M.; Grover, O.; Gruca, M.; Gude, A.; Guimarais, L.; Gyergyek, T.; Hacek, P.; Hakola, A.; Ham, C.; Happel, T.; Harrison, J.; Havranek, A.; Hawke, J.; Henderson, S.; Hesslow, L.; Hitzler, F.; Hnat, B.; Hobirk, J.; Hoelzl, M.; Hogeweij, D.; Hopf, C.; Hoppe, M.; Horacek, J.; Hron, M.; Huang, Z.; Iantchenko, A.; Iglesias, D.; Igochine, V.; Innocente, P.; Ionita-Schrittwieser, C.; Isliker, H.; Ivanova-Stanik, I.; Jacobsen, A.; Jakubowski, M.; Janky, F.; Jardin, A.; Jaulmes, F.; Jensen, T.; Jonsson, T.; Kallenbach, A.; Kappatou, A.; Karpushov, A.; Kasilov, S.; Kazakov, Y.; Kazantzidis, P. V.; Keeling, D.; Kelemen, M.; Kendl, A.; Kernbichler, W.; Kirk, A.; Kocsis, G.; Komm, M.; Kong, M.; Korovin, V.; Koubiti, M.; Kovacic, J.; Krawczyk, N.; Krieger, K.; Kripner, L.; Křivská, A.; Kudlacek, O.; Kulyk, Y.; Kurki-Suonio, T.; Kwiatkowski, R.; Laggner, F.; Laguardia, L.; Lahtinen, A.; Lang, P.; Likonen, J.; Lipschultz, B.; Liu, F.; Lombroni, R.; Lorenzini, R.; Loschiavo, V. P.; Lunt, T.; MacUsova, E.; Madsen, J.; Maggiora, R.; Maljaars, B.; Manas, P.; Mantica, P.; Mantsinen, M. J.; Manz, P.; Maraschek, M.; Marchenko, V.; Marchetto, C.; Mariani, A.; Marini, C.; Markovic, T.; Marrelli, L.; Martin, P.; Martín Solís, J. R.; Martitsch, A.; Mastrostefano, S.; Matos, F.; Matthews, G.; Mayoral, M.-L.; Mazon, D.; Mazzotta, C.; Mc Carthy, P.; McClements, K.; McDermott, R.; McMillan, B.; Meineri, C.; Menkovski, V.; Meshcheriakov, D.; Messmer, M.; Micheletti, D.; Milanesio, D.; Militello, F.; Miron, I. G.; Mlynar, J.; Moiseenko, V.; Molina Cabrera, P. A.; Morales, J.; Moret, J.-M.; Moro, A.; Moulton, D.; Nabais, F.; Naulin, V.; Naydenkova, D.; Nem, R. D.; Nespoli, F.; Newton, S.; Nielsen, A. H.; Nielsen, S. K.; Nikolaeva, V.; Nocente, M.; Nowak, S.; Oberkofler, M.; Ochoukov, R.; Ollus, P.; Olsen, J.; Omotani, J.; Ongena, J.; Orain, F.; Orsitto, F. P.; Paccagnella, R.; Palha, A.; Panaccione, L.; Panek, R.; Panjan, M.; Papp, G.; Paradela Perez, I.; Parra, F.; Passeri, M.; Pau, A.; Pautasso, G.; Pavlichenko, R.; Perek, A.; Pericoli Radolfini, V.; Pesamosca, F.; Peterka, M.; Petrzilka, V.; Piergotti, V.; Pigatto, L.; Piovesan, P.; Piron, C.; Piron, L.; Plyusnin, V.; Pokol, G.; Poli, E.; Pölöskei, P.; Popov, T.; Popovic, Z.; Pór, G.; Porte, L.; Pucella, G.; Puiatti, M. E.; Pütterich, T.; Rabinski, M.; Juul Rasmussen, J.; Rasmussen, J.; Rattá, G. A.; Ratynskaia, S.; Ravensbergen, T.; Réfy, D.; Reich, M.; Reimerdes, H.; Reimold, F.; Reiser, D.; Reux, C.; Reznik, S.; Ricci, D.; Rispoli, N.; Rivero-Rodriguez, J. F.; Rocchi, G.; Rodriguez-Ramos, M.; Romano, A.; Rosato, J.; Rubinacci, G.; Rubino, G.; Ryan, D. A.; Salewski, M.; Salmi, A.; Samaddar, D.; Sanchis-Sanchez, L.; Santos, J.; Särkimäki, K.; Sassano, M.; Sauter, O.; Scannell, R.; Scheffer, M.; Schneider, B. S.; Schneider, P.; Schrittwieser, R.; Schubert, M.; Seidl, J.; Seliunin, E.; Sharapov, S.; Sheeba, R. R.; Sias, G.; Sieglin, B.; Silva, C.; Sipilä, S.; Smith, S.; Snicker, A.; Solano, E. R.; Hansen, S. K.; Soria-Hoyo, C.; Sorokovoy, E.; Sozzi, C.; Sperduti, A.; Spizzo, G.; Spolaore, M.; Stejner, M.; Stipani, L.; Stober, J.; Strand, P.; Sun, H.; Suttrop, W.; Sytnykov, D.; Szepesi, T.; Tál, B.; Tala, T.; Tardini, G.; Tardocchi, M.; Teplukhina, A.; Terranova, D.; Testa, D.; Theiler, C.; Thorén, E.; Thornton, A.; Tilia, B.; Tolias, P.; Tomes, M.; Toscano-Jimenez, M.; Tsironis, C.; Tsui, C.; Tudisco, O.; Urban, J.; Valisa, M.; Vallar, M.; Vallejos Olivares, P.; Valovic, M.; Van Vugt, D.; Vanovac, B.; Varje, J.; Varju, J.; Varoutis, S. 1; Vartanian, S.; Vasilovici, O.; Vega, J.; Verdoolaege, G.; Verhaegh, K.; Vermare, L.; Vianello, N.; Vicente, J.; Viezzer, E.; Villone, F.; Voitsekhovitch, I.; Voltolina, D.; Vondracek, P.; Vu, N. M. T.; Walkden, N.; Wauters, T.; Weiland, M.; Weinzettl, V.; Wensing, M.; Wiesen, S.; Wiesenberger, M.; Wilkie, G.; Willensdorfer, M.; Wischmeier, M.; Wu, K.; Xiang, L.; Zagorski, R.; Zaloga, D.; Zanca, P.; Zaplotnik, R.; Zebrowski, J.; Zhang, W.; Zisis, A.; Zoletnik, S.; Zuin, M.
Published: 2019
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3. Runaway electron beam stability and decay in COMPASS

Author: M. Vlainic, A. Casolari, Petr Kulhánek, Josef Havlicek, D. Naydenkova, Petr Vondracek, Tomas Markovic, Compass Team, M. Rabinski, Y. Peysson, Martin Imrisek, Daniele Carnevale, J. Krbec, Marco Gobbin, A. Havranek, M. Gospodarczyk, C. Reux, Ondrej Ficker, Radomir Panek, Vaclav Vrba, Eva Macusova, Jakub Urban, Gergely Papp, David Bren, Vladimír Linhart, Jan Mlynar, V.V. Plyusnin, Vladimir Weinzettl, M. Farnik, M. Jerab, J. Cerovsky, Martin Hron, M. Sos, O. Grover, Jozef Varju, V. Svoboda, M. Marcisovsky, Peter Svihra, M. Tomes, J. Decker, COMPASS Team, and EUROfusion MST1 Team
Subjects: Nuclear and High Energy Physics, Settore ING-INF/04, Tokamak, chemistry.chemical_element, Electron, Effective radiated power, tomography, disruptions, 7. Clean energy, 01 natural sciences, 010305 fluids & plasmas, law.invention, Neon, law, 0103 physical sciences, 010306 general physics, Physics, Argon, COMPASS tokamak, runaway electrons, Plasma, Condensed Matter Physics, Computational physics, chemistry, tokamaks, Beam (structure)
Abstract: This paper presents two scenarios used for generation of a runaway electron (RE) beam in the COMPASS tokamak with a focus on the decay phase and control of the beam. The first scenario consists of massive gas injection of argon into the current ramp-up phase, leading to a disruption accompanied by runaway plateau generation. In the second scenario, injection of a smaller amount of gas is used in order to isolate the RE beam from high-temperature plasma. The performances of current control and radial and vertical position feedback control in the second scenario were experimentally studied and analysed. The role of RE energy in the radial position stability of the RE beam seems to be crucial. A comparison of the decay phase of the RE beam in various amounts of Ar or Ne was studied using absolute extreme ultraviolet (AXUV) tomography and hard x-ray (HXR) intensity measurement. Argon clearly leads to higher HXR fluxes for the same current decay rate than neon, while radiated power based on AXUV measurements is larger for Ne in the same set of discharges.
Published: 2019
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4. Tomographic capabilities of the new GEM based SXR diagnostic of WEST

Author: Martin Imrisek, Didier Mazon, M. G. O'Mullane, Maryna Chernyshova, Grzegorz Kasprowicz, A. Jardin, Viktor Loffelmann, P. Malard, Andrzej Wojeński, Clarisse Bourdelle, Tomasz Czarski, Jan Mlynar, Institut de Recherche sur la Fusion par confinement Magnétique (IRFM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Department of Physics [Glasgow], University of Strathclyde [Glasgow], Institute of Plasma Physics, Association EURATOM (IPP PRAGUE), Czech Academy of Sciences [Prague] (CAS), Institute of Plasma Physics and Laser Microfusion [Warsaw] (IPPLM), and Warsaw University of Technology [Warsaw]
Subjects: Tokamak, Radiative cooling, Soft X-Ray Tomography, Context (language use), Tore Supra, 7. Clean energy, 01 natural sciences, 010305 fluids & plasmas, law.invention, Plasma diagnostics, Optics, law, Physics::Plasma Physics, [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], 0103 physical sciences, Emissivity, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], 010306 general physics, Instrumentation, Mathematical Physics, Physics, GEM, business.industry, Divertor, Electrical engineering, 13. Climate action, Gas electron multiplier, business, Noise (radio), Tokamaks
Abstract: International audience; The tokamak WEST (Tungsten Environment in Steady-State Tokamak) will start operating by the end of 2016 as a test bed for the ITER divertor components in long pulse operation. In this context, radiative cooling of heavy impurities like tungsten (W) in the Soft X-ray (SXR) range [0.1 keV; 20 keV] is a critical issue for the plasma core performances. Thus reliable tools are required to monitor the local impurity density and avoid W accumulation. The WEST SXR diagnostic will be equipped with two new GEM (Gas Electron Multiplier) based poloidal cameras allowing to perform 2D tomographic reconstructions in tunable energy bands. In this paper tomographic capabilities of the Minimum Fisher Information (MFI) algorithm developed for Tore Supra and upgraded for WEST are investigated, in particular through a set of emissivity phantoms and the standard WEST scenario including reconstruction errors, influence of noise as well as computational time.
Published: 2016
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5. Minimum Fisher Tikhonov Regularization Adapted to Real-Time Tomography

Author: V. Loffelmann, A. Jardin, Martin Imrisek, Jan Mlynar, Vladimir Weinzettl, Martin Hron, Didier Mazon, Czech Technical University in Prague (CTU), Institute of Plasma Physics, Association EURATOM (IPP PRAGUE), Czech Academy of Sciences [Prague] (CAS), Faculty of Mathematics and Physics [Praha/Prague], Charles University [Prague] (CU), Institut de Recherche sur la Fusion par confinement Magnétique (IRFM), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
Subjects: 010302 applied physics, Physics, Nuclear and High Energy Physics, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], Mechanical Engineering, [PHYS.MPHY]Physics [physics]/Mathematical Physics [math-ph], Plasma radiation, Inversion (meteorology), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, eye diseases, 010305 fluids & plasmas, Tikhonov regularization, Nuclear Energy and Engineering, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], General Materials Science, sense organs, Tomography, Algorithm, Civil and Structural Engineering
Abstract: International audience; Tomography inversion has been used routinely for processing outputs of plasma radiation diagnostics. Various tomographic algorithms have been developed, with those based on Tikhonov regularization being among the fastest while still providing reliable results. This paper presents a further speed optimization of the minimum Fisher Tikhonov regularization algorithm based on reducing iteration cycles used during the calculation. Ten to twentyfold speed gain is achieved compared to the original implementation. Robustness of the new method is demonstrated using both artificially generated data sets and real data from the soft X-ray diagnostics at the COMPASS tokamak. The advantage gained by the optimization is investigated in particular with respect to the possibility of real-time control of the plasma position; the option of impurity control is also discussed.
Published: 2016
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6. Design of soft-X-ray tomographic system in WEST using GEM detectors

Author: Tomasz Czarski, Jan Mlynar, Wojciech M. Zabołotny, Didier Mazon, Guillaume Jiolat, S. Larroque, R. Zagórski, Ewa Kowalska-Strzęciwilk, P. Malard, Andrzej Wojeński, S. Jablonski, M. G. O'Mullane, Adrian Byszuk, W. Figacz, Maryna Chernyshova, Jean Marc Verger, Monika Kubkowska, Krzysztof T. Pozniak, and Grzegorz Kasprowicz
Subjects: Tokamak, Physics::Instrumentation and Detectors, Tore Supra, 01 natural sciences, Particle detector, 010305 fluids & plasmas, law.invention, Nuclear physics, Optics, Physics::Plasma Physics, law, 0103 physical sciences, General Materials Science, QC, Civil and Structural Engineering, Diode, 010302 applied physics, Physics, business.industry, Mechanical Engineering, Divertor, Detector, Nuclear Energy and Engineering, TA174, Gas electron multiplier, Tomography, business
Abstract: In metallic tokamaks, the interplay between particle transport and MagnetoHydroDynamic (MHD) activity might lead to impurities accumulation and finally to disruption. Studying such phenomena is thus essential if stationary discharges are to be achieved. Measuring the soft X-ray (SXR) radiation ([0.1 keV; 20 keV]) of magnetic fusion plasmas is a standard way of accessing valuable information on particle transport and MHD. Generally, like at Tore Supra (TS), the analysis is performed with a 2D tomographic system composed of several cameras equipped with silicon barrier diodes (SBD). On WEST the installation of an upper divertor masks many of the actual TS vertical diodes so that no proper tomography is possible. This paper presents the design of a new SXR diagnostic for the WEST project developed in collaboration with IPPLM (Poland) and the Warsaw University of Technology, based on a triple gas electron multiplier (GEM) detector. Preliminary simulations performed to size and position the detector and its electronics inside the vertical thimble are also presented, in particular estimation of magnetic field and temperature variation affecting GEM spatial resolution and signal quality. As a conclusion, perspectives about tomographic capabilities of the new system for studying impurity transport are given.
Published: 2015

7. ITER-like current ramps in JET with ILW: experiments, modelling and consequences for ITER

Author: E. Joffrin, G. Calabrò, Francesco Maviglia, Jet-Efda Contributors, F.G. Rimini, G. M. D. Hogeweij, G. De Tommasi, C. F. Maggi, A. Loarte, A. C. C. Sips, Jan Mlynar, Th. Pütterich, G., Hogeweij, G., Calabrò, A., Sip, C., Maggi, DE TOMMASI, Gianmaria, E., Joffrin, A., Loarte, F., Maviglia, J., Mlynar, F., Rimini, T., Puetterich, Calabrò, G., and JET EFDA Contributors
Subjects: Nuclear and High Energy Physics, Jet (fluid), Materials science, Flux, Plasma, Radiation, Condensed Matter Physics, 01 natural sciences, 010305 fluids & plasmas, Nuclear physics, Inductance, JET, tokamak, ramp-up, ITER, Phase (matter), 0103 physical sciences, Electron temperature, Current (fluid), 010306 general physics
Abstract: Since the ITER-like wall in JET (JET-ILW) came into operation, dedicated ITER-like plasma current (I p) ramp-up (RU) and ramp-down (RD) experiments have been performed and matched to similar discharges with the carbon wall (JET-C). The experiments show that access to H-mode early in the I p RU phase and maintaining H-mode in the I p RD as long as possible are instrumental to achieve low internal plasma inductance (l i) and to minimize flux consumption. In JET-ILW, at a given current rise rate similar variations in l i (0.7–0.9) are obtained as in JET-C. In most discharges no strong W accumulation is observed. However, in some low density cases during the early phase of the I p strong core radiation due to W influx led to hollow electron temperature (T e) profiles. In JET-ILW Z eff is significantly lower than in JET-C. W significantly disturbs the discharge evolution when the W concentration approaches 10−4; this threshold is confirmed by predictive transport modelling using the CRONOS code. I p RD experiments in JET-ILW confirm the result of JET-C that sustained H-mode and elongation reduction are both instrumental in controlling l i.
Published: 2015
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8. Tungsten transport in JET H-mode plasmas in hybrid scenario, experimental observations and modelling

Author: P. Belo, N. C. Hawkes, T. Odstrcil, Emily Belli, C. Challis, L. Lauro Taroni, Jet-Efda Contributors, Th. Pütterich, P. Mantica, J. Hobirk, M. Romanelli, P. Drewelow, Matthew Reinke, C. Giroud, Jan Mlynar, T. C. Hender, C. Angioni, F. J. Casson, M. Baruzzo, C. F. Maggi, M. Valisa, Tuomas Koskela, and JET EFDA Contributors
Subjects: Convection, Physics, Nuclear and High Energy Physics, Jet (fluid), H-mode hybrid scenario, Turbulence, Mode (statistics), chemistry.chemical_element, neoclassical and turbulent transport, Plasma, Mechanics, Tungsten, heavy impurity transport, Condensed Matter Physics, 01 natural sciences, 010305 fluids & plasmas, chemistry, 13. Climate action, Phase (matter), 0103 physical sciences, Tearing, Atomic physics, 010306 general physics
Abstract: The behaviour of tungsten in the core of hybrid scenario plasmas in JET with the ITER-like wall is analysed and modelled with a combination of neoclassical and gyrokinetic codes. In these discharges, good confinement conditions can be maintained only for the first 2?3?s of the high power phase. Later W accumulation is regularly observed, often accompanied by the onset of magneto-hydrodynamical activity, in particular neoclassical tearing modes (NTMs), both of which have detrimental effects on the global energy confinement. The dynamics of the accumulation process is examined, taking into consideration the concurrent evolution of the background plasma profiles, and the possible onset of NTMs. Two time slices of a representative discharge, before and during the accumulation process, are analysed with two independent methods, in order to reconstruct the W density distribution over the poloidal cross-section. The same time slices are modelled, computing both neoclassical and turbulent transport components and consistently including the impact of centrifugal effects, which can be significant in these plasmas, and strongly enhance W neoclassical transport. The modelling closely reproduces the observations and identifies inward neoclassical convection due to the density peaking of the bulk plasma in the central region as the main cause of the accumulation. The change in W neoclassical convection is directly produced by the transient behaviour of the main plasma density profile, which is hollow in the central region in the initial part of the high power phase of the discharge, but which develops a significant density peaking very close to the magnetic axis in the later phase. The analysis of a large set of discharges provides clear indications that this effect is generic in this scenario. The unfavourable impact of the onset of NTMs on the W behaviour, observed in several discharges, is suggested to be a consequence of a detrimental combination of the effects of neoclassical transport and of the appearance of an island.
Published: 2014
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9. ICRF heating in JET during initial operations with the ITER-like wall

Author: A. Sirinelli, Jet-Efda Contributors, L. Colas, D. Van-Eester, M.-L. Mayoral, A. L. Campergue, Th. Pütterich, A. G. Meigs, Ph. Jacquet, A. Czarnecka, Jan Mlynar, I. Monakhov, E. Lerche, Daniele Milanesio, V. Bobkov, S. Brezinsek, P. Drewelow, C. Christopher Klepper, M. E. Graham, M. Brix, and JET-EFDA Contributors
Subjects: Jet (fluid), Chemistry, Divertor, Limiter, chemistry.chemical_element, Plasma, Atomic physics, Beryllium, Tungsten, Neutral beam injection, Ion cyclotron resonance
Abstract: In 2011/12, JET started operation with its new ITER-Like Wall (ILW) made of a tungsten (W) divertor and a beryllium (Be) main chamber wall. The impact of the new wall material on the JET Ion Cyclotron Resonance Frequency (ICRF) operation was assessed and also the properties of JET plasmas heated with ICRF were studied. No substantial change of the antenna coupling resistance was observed with the ILW as compared with the carbon wall. Heat-fluxes on the protecting limiters close the antennas quantified using Infra-Red (IR) thermography (maximum 4.5 MW/m2 in current drive phasing) are within the wall power load handling capabilities. A simple RF sheath rectification model using the antenna near-fields calculated with the TOPICA code can well reproduce the heat-flux pattern around the antennas. ICRF heating results in larger tungsten and nickel (Ni) contents in the plasma and in a larger core radiation when compared to Neutral Beam Injection (NBI) heating. Some experimental facts indicate that main-chamber W components could be an important impurity source: the divertor W influx deduced from spectroscopy is comparable when using RF or NBI at same power and comparable divertor conditions; the W content is also increased in ICRF-heated limiter plasmas; and Be evaporation in the main chamber results in a strong and long lasting reduction of the impurity level. The ICRF specific high-Z impurity content decreased when operating at higher plasma density and when increasing the hydrogen concentration from 5% to 20%. Despite the higher plasma bulk radiation, ICRF exhibited overall good plasma heating efficiency; The ICRF power can be deposited at plasma centre and the radiation is mainly from the outer part of the plasma. Application of ICRF heating in H-mode plasmas started, and the beneficial effect of ICRF central electron heating to prevent W accumulation in the plasma core could be observed.
Published: 2014

10. Ion cyclotron resonance frequency heating in JET during initial operations with the ITER-like wall

Author: Jet-Efda Contributors, L. Colas, Ernesto Lerche, V. Bobkov, P. Drewelow, Ph. Jacquet, A. Sirinelli, A. G. Meigs, Stéphane Devaux, M. Brix, M. E. Graham, C. Christopher Klepper, Daniele Milanesio, S. Brezinsek, Jan Mlynar, M.-L. Mayoral, Th. Pütterich, A. Czarnecka, I. Monakhov, G. Arnoux, D. Van-Eester, A. L. Campergue, EURATOM/CCFE Fusion Association, Culham Science Centre [Abingdon], Max-Planck-Institut für Plasmaphysik [Garching] (IPP), Institut de Recherche sur la Fusion par confinement Magnétique (IRFM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institute of Plasma Physics and Laser Microfusion [Warsaw] (IPPLM), Euratom-Belgian State Association, European Fusion Development Agreement [Garching bei München] ( EFDA-CSU), Institute of Energy and Climate Research - Plasma Physics (IEK-4), Forschungszentrum Jülich GmbH | Centre de recherche de Juliers, Helmholtz-Gemeinschaft = Helmholtz Association-Helmholtz-Gemeinschaft = Helmholtz Association, École des Ponts ParisTech (ENPC), Oak Ridge National Laboratory [Oak Ridge] (ORNL), UT-Battelle, LLC, Department of Electronics, Politecnico di Torino = Polytechnic of Turin (Polito), Institute of Plasma Physics, Association Euratom/IPP.CR (IPP PRAGUE), Czech Academy of Sciences [Prague] (CAS), Joint European Torus (JET-EFDA), and JET-EFDA Contributors
Subjects: Physics, Jet (fluid), Divertor, chemistry.chemical_element, Plasma, Tungsten, Condensed Matter Physics, 7. Clean energy, Neutral beam injection, chemistry, [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], Limiter, Plasma diagnostics, ddc:530, Atomic physics, Ion cyclotron resonance
Abstract: Équipe 107 : Physique des plasmas chauds; International audience; In 2011/12, JET started operation with its new ITER-Like Wall (ILW) made of a tungsten (W) divertor and a beryllium (Be) main chamber wall. The impact of the new wall materials on the JET Ion Cyclotron Resonance Frequency (ICRF) operation is assessed and some important properties of JET plasmas heated with ICRF are highlighted. A similar to 20% reduction of the antenna coupling resistance is observed with the ILW as compared with the JET carbon (JET-C) wall. Heat-fluxes on the protecting limiters close the antennas, quantified using Infra-Red thermography (maximum 4.5MW/m(2) in current drive phasing), are within the wall power load handling capabilities. A simple RF sheath rectification model using the antenna near-fields calculated with the TOPICA code can reproduce the heat-flux pattern around the antennas. ICRF heating results in larger tungsten and nickel (Ni) contents in the plasma and in a larger core radiation when compared to Neutral Beam Injection (NBI) heating. The location of the tungsten ICRF specific source could not be identified but some experimental observations indicate that main-chamber W components could be an important impurity source: for example, the divertor W influx deduced from spectroscopy is comparable when using RF or NBI at same power and comparable divertor conditions, and Be evaporation in the main chamber results in a strong reduction of the impurity level. In L-mode plasmas, the ICRF specific high-Z impurity content decreased when operating at higher plasma density and when increasing the hydrogen concentration from 5% to 15%. Despite the higher plasma bulk radiation, ICRF exhibited overall good plasma heating performance; the power is typically deposited at the plasma centre while the radiation is mainly from the outer part of the plasma bulk. Application of ICRF heating in H-mode plasmas has started, and the beneficial effect of ICRF central electron heating to prevent W accumulation in the plasma core has been observed.
Published: 2014
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11. Unfolding of energies of fusion products from the nuclear activation data at JET

Author: Jan Mlynar, G. Bonheure, O. Ficker, K. Bauer, S. Popovichev, A. Murari, and JET EFDA Contributors Collaboration
Abstract: Diagnostics of fusion products, in particular of energetic charged particles, is a challenging task that requires further development. In this respect, activation probes were tested in JET, TEXTOR and ASDEX-U tokamaks as a novel and robust diagnostics, compatible with harsh conditions in future fusion reactors. The activation probe consists of a set of pure, well-characterized materials in which measureable amounts of radioisotopes are produced from nuclear reactions due to energetic particles. The production of each radioisotope can be modelled by an energy dependent yield curve derived from the specific nuclear reaction cross section data. In this contribution, the JET activation probe data will be reviewed with focus on possible spectral reconstruction of the incident fusion particles. A method will be outlined to reliably unfold neutron and proton energies, based on Tikhonov regularisation. First results of the neutron and proton energy spectra unfolded from the activation data will be presented. Although the analyses of the proton data are more complex due to several geometrical factors, the initial results demonstrate the potential of this robust diagnostic method, provided that the ill-conditioned task of unfolding is carefully implemented.
Published: 2013

12. Modern numerical methods for plasma tomography optimisation

Author: T. Odstrcil, Jet-Efda Contributors, Andrea Murari, B. Alper, Jan Mlynar, and Michal Odstrcil
Subjects: Physics, Nuclear and High Energy Physics, MFI, business.industry, Numerical analysis, Computation, Stability (learning theory), Soft X-rays, Inverse problem, Imaging, Tikhonov regularization, symbols.namesake, Optics, Fusion plasmas, symbols, Emissivity, Tomography, Fisher information, business, Instrumentation, Algorithm
Abstract: Tomography is a technique which is widely applied to fusion plasmas as it can provide improved understanding of plasma emissivity distributions. It is challenging because of the sparse nature of data available from the measured plasma projections. An optimised version of robust and fast tomographic algorithm based on the Tikhonov regularisation constrained to Minimum Fisher Information is presented in this contribution. A new regularisation matrix enforcing preferential emissivity smoothness along magnetic flux surfaces is introduced. The paper also details application of advanced numerical methods which lead to a substantial decrease in computation time. Subsequent implementation of fast presolvers of the inverse problem further contributes to the algorithm's efficiency and also an improved stability of the tomography reconstruction. Finally, reliability and performance of the tomography algorithm is exemplified by the reconstruction of soft X-ray data evolution following tungsten ablation into a JET plasma. The resulting speed of reconstruction is compared to other referenced tomographic algorithms.
Published: 2012
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13. Introducing minimum Fisher regularisation tomography to AXUV and soft x-ray diagnostic systems of the COMPASS tokamak

Author: B. Alper, Vladimir Weinzettl, Jan Mlynar, A. Murari, Michal Odstrcil, F. Janky, Josef Havlicek, Jet-Efda Contributors, and Martin Imrisek
Subjects: Physics, Tomographic reconstruction, COMPASS tokamak, business.industry, Joint European Torus, PLASMAS, Nuclear physics, Optics, Compass, Extreme ultraviolet, Limiter, Plasma diagnostics, Tomography, TCV, business, Instrumentation
Abstract: The contribution focuses on plasma tomography via the minimum Fisher regularisation (MFR) algorithm applied on data from the recently commissioned tomographic diagnostics on the COMPASS tokamak. The MFR expertise is based on previous applications at Joint European Torus (JET), as exemplified in a new case study of the plasma position analyses based on JET soft x-ray (SXR) tomographic reconstruction. Subsequent application of the MFR algorithm on COMPASS data from cameras with absolute extreme ultraviolet (AXUV) photodiodes disclosed a peaked radiating region near the limiter. Moreover, its time evolution indicates transient plasma edge cooling following a radial plasma shift. In the SXR data, MFR demonstrated that a high resolution plasma positioning independent of the magnetic diagnostics would be possible provided that a proper calibration of the cameras on an x-ray source is undertaken.
Published: 2012
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14. Charged fusion product loss measurements using nuclear activation

Author: Sergey Popovichev, Andrea Murari, Matthias Laubenstein, D. Arnold, P. Vermaercke, E. Wieslander, R. González de Orduña, H. Dombrowski, G. Bonheure, Jet-Efda Contributors, Mikael Hult, and Jan Mlynar
Subjects: Physics, Nuclear reaction, Proton, GAMMA-RAY SPECTROMETRY, Alpha particle, Plasma, Fusion power, DIAGNOSTICS, Charged particle, Ion, ION LOSS MEASUREMENTS, Physics::Plasma Physics, JET, Gamma spectroscopy, Atomic physics, Instrumentation
Abstract: In ITER, α particle loss measurements will be required in order to understand the alpha particle physics. Techniques capable of operating in a fusion reactor environment need further development. Recent experimental studies on JET demonstrated the potential of nuclear activation to measure the flux of escaping MeV ions. New results from MeV ion induced activation of metallic, ceramic, and crystal samples placed near the plasma edge are reported. Activation products were measured as function of orientation with respect to the magnetic field as well as function of the distance to the plasma. Sample activity was measured using ultralow-level gamma-ray spectrometry. Distribution of 14.68 MeV fusion proton induced activation products is strongly anisotropic in agreement with simulations and falls off sharply with increasing distance to the plasma. Prospects for using the technique in ITER are discussed.
Published: 2010
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15. Design of multi-range tomographic system for transport studies in tokamak plasmas

Author: J. Malot, Jan Mlynar, Radek Melich, D. Sestak, D. I. Naydenkova, D. Jares, D. Sarychev, V. Igochine, J. Vlcek, and Vladimir Weinzettl
Subjects: Physics, Nuclear and High Energy Physics, Tokamak, Tomographic reconstruction, COMPASS tokamak, business.industry, Bolometer, Atmospheric-pressure plasma, Plasma, law.invention, Optics, law, Compass, business, Instrumentation, Image resolution
Abstract: The integrated spectroscopic system for visible plasma radiation, soft X-ray, and bolometric measurements has been designed for the COMPASS tokamak. This diagnostic allows tomographic reconstruction at a few microseconds time base and features an improved spatial resolution about 1 cm in the pedestal region, where the highest gradient of plasma pressure drives turbulent structures and their propagation towards the wall. In combination with other developed diagnostics on COMPASS, it represents an ideal tool for a measurement and characterization of these radiating plasma structures, which are responsible for an extremely high particle/energy transport across magnetic field. The design of the new integrated multi-channel spectroscopic diagnostics is reviewed and corresponding technical challenges are described. Additionally, the methods, which will be used for data processing, are briefly mentioned and target physics is discussed.
Published: 2010

16. Burning plasma diagnostics for the physics of JET and ITER

Author: Jan Mlynar, M. Tardocchi, Sergey Popovichev, V. Afanasyiev, V. G. Kiptily, G. Bonheure, Göran Ericsson, Jan Källne, Sean Conroy, Luciano Bertalot, K. D. Lawson, K.-D. Zastrow, D. Testa, Andrea Murari, Ambrogio Fasoli, Maurizio Angelone, Jet-Efda Contributors, and M Mironov
Subjects: Nuclear physics, Physics, Range (particle radiation), Jet (fluid), Nuclear Energy and Engineering, Neutron emission, Neutron detection, Neutron, Plasma diagnostics, Plasma, Condensed Matter Physics, Neutron spectroscopy
Abstract: JET's recent experimental programme proved that 'burning plasma diagnostics', i.e. neutron, alpha particle, He ash, and fuel mixture measurements, can provide very useful information about crucial physical aspects of great reactor relevance. First of all, several of these diagnostics can improve the diagnostic capability of the ion fluid significantly. During TTE spatially resolved neutron measurements at JET were essential in obtaining the isotopic composition and the transport of the hydrogen isotopes, allowing a direct comparison between the measured transport coefficients and the neoclassical theory. The neutron emission profiles can also give crucial indications for assessing the merits of various heating schemes and their current drive capability. Neutron spectroscopy in its turn provides a clear and direct measurement of the temperature and the velocity distribution of the fuel ions. For example, the dependence of the toroidal velocity from the ion cyclotron radiofrequency heating phasing was clearly seen during TTE. The requirements of accurate neutron measurements are also promoting considerable research in detector technology, in particular in the fields of compact spectrometers and solid state detectors. 'Burning plasma' diagnostics can also strongly contribute to the physics of energetic particles and their interaction with the main plasma. gamma-Ray spectroscopy is now an established method to determine the spatial localization, to visualize the trajectories of the alpha particles and the fast deuterons and to obtain estimates of their slowing down. A completely new method to detect the energetic particles, exploiting the line intensity ratio of extreme ultraviolet radiation emitted by suitable extrinsic impurities, is also being pursued. This technique allows investigating the energy range below 600 keV, extremely interesting for the study of wave-particle interactions.
Published: 2005
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17. Overview of TCV results

Author: P. Gomez, B. P. Duval, Stefano Alberti, A. Favre, P. Gorgerat, K. Appert, G. Tonetti, René Chavan, A. Manini, P. J. Paris, Timothy Goodman, Y. R. Martin, I. Condrea, V.E. Lukash, J.-C. Magnin, P. F. Isoz, An. Martynov, B. Joye, Yves Peysson, Damien Fasel, Ivo Furno, C. Angioni, Jean-Philippe Hogge, A. V. Sushkov, R. Behn, H. Reimerdes, A. Pochelon, V. Piffl, P. Nikkola, J.-Y. Favez, J. Bakos, E. Scavino, Z.A. Pietrzyk, Minh Quang Tran, J.-M. Mayor, F. Hofmann, A. Perez, P. Marmillod, X. Llobet, H. Weisen, A. Zabolotsky, Jean-Marc Moret, R.A. Pitts, Alex Degeling, J. Rommers, P. Lavanchy, E. Minardi, B. Marletaz, Olivier Sauter, P. Blanchard, R. R. Kayruthdinov, Stefano Coda, Jan Mlynar, P. Bosshard, J.B. Lister, A. Loarte, and M. A. Henderson
Subjects: Physics, Nuclear physics, Nuclear and High Energy Physics, law, Gyrotron, Second-harmonic generation, Plasma confinement, Fusion power, Condensed Matter Physics, Mhd instability, __, Particle transport, law.invention
Abstract: The TCV tokamak (R = 0.88 in, a < 0.25 in, BT < 1.54 T) is equipped with six 0.5 MW gyrotron sources operating at 82.7 GHz for second harmonic X mode ECH. By distributing the ECCD current sources over the discharge cross section, fully driven stationary plasmas with I-p = 210 kA, n(e0) = 2 x 10(19) m(-3), T-e0 approximate to 4 keV, were obtained for the full discharge duration of 2 s. Highly peaked electron temperature profiles with T-e0 up to 12 keV were obtained in central counter-current drive scenarios with off-axis ECH. Absorption measurements using a 118 GHz gyrotron have demonstrated the importance of suprathermal electrons for third harmonic absorption. A coupled heat-particle transport phenomenon known as 'density pumpout', which leads to the expulsion of particles from the plasma core, has been linked to the presence of m = I modes, suggesting that it is due to the existence of locally trapped particles associated with the loss of axisymmetry. Highly elongated discharges have been developed with ohmic heating (kappa < 2.8) and off-axis ECH. The latter exhibit considerably improved vertical stability due to current profile broadening. A 'gateway' for ELMy H modes has been discovered, which allows stationary ohmic ELMy H mode operation over a wide range of elongation, triangularity and density. Divertor detachment experiments suggest the existence of recombination pathways other than three body or radiative processes.
Published: 2001

18. Steady-state fully noninductive operation with electron cyclotron current drive and current profile control in the tokamak à configuration variable (TCV)

Author: A. Favre, G. Tonetti, A. Manini, H. Weisen, J.B. Lister, Stefano Alberti, A. Perez, Jean-Marc Moret, J. Bakos, Z.A. Pietrzyk, A. Sushkov, Olivier Sauter, M. A. Henderson, R. R. Kayruthdinov, R. Behn, V.E. Lukash, Stefano Coda, H. Reimerdes, J.-C. Magnin, P. F. Isoz, René Chavan, B. Marletaz, V. Piffl, An. Martynov, Y. R. Martin, I. Condrea, J.-Y. Favez, C. Angioni, Ph. Marmillod, P. Gomez, R.A. Pitts, B. P. Duval, P. Bosshard, Alex Degeling, A. Zabolotsky, Minh Quang Tran, P. Gorgerat, P. Blanchard, J. Rommers, P. Lavanchy, Damien Fasel, T. P. Goodman, Jean-Philippe Hogge, Ivo Furno, P. J. Paris, K. Appert, E. Scavino, F. Hofmann, B. Joye, J.-M. Mayor, Jan Mlynar, X. Llobet, Y. Peysson, P. Nikkola, A. Pochelon, and E. Minardi
Subjects: Physics, Cyclotron, Electron, Sawtooth wave, Plasma, Condensed Matter Physics, Instability, law.invention, Amplitude, ___, law, Tokamak à configuration variable, Atomic physics, Transformer
Abstract: Fully noninductive, steady-state electron cyclotron current drive (ECCD) has been demonstrated for the first time in experiments carried out in the tokamak a configuration variable (TCV) [O. Sauter , Phys. Rev. Lett. 84, 3322 (2000)]. By appropriately distributing six 0.45 MW ECCD sources over the discharge cross section, fully noninductive, stable, and stationary plasmas with I-p up to 210 kA were obtained for the full discharge duration of 1.9 s, corresponding to more than 900 energy confinement times and more than 10 current redistribution times at an average current drive efficiency eta (20CD)=0.01[10(20) A W-1 m(-2)]. These experiments have also demonstrated for the first time the steady recharging of the ohmic transformer using ECCD only. The effect of localized off-axis electron cyclotron heating (ECH) and EC current drive (ECCD) (co- and counter-) is investigated showing that locally driven currents amounting to only 1% of I-p significantly alter sawtooth periods and crash amplitudes. An improved quasi-stationary core confinement regime, with little or no sawtooth activity, has been obtained by a combination of off-axis ECH and on-axis CNTR-ECCD. (C) 2001 American Institute of Physics.
Published: 2001
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19. Post-disruptive runaway electron beams in the COMPASS tokamak

Author: Martin Imrisek, Jan Mlynar, M. Varavin, Petr Vondracek, M. Vlainic, Jean-Marie Noterdaeme, R. Paprok, Jordan Cavalier, Vladimir Weinzettl, Ondrej Ficker, and COMPASS Team
Subjects: Physics, Electron density, Range (particle radiation), Argon, COMPASS tokamak, chemistry.chemical_element, Electron, Condensed Matter Physics, 01 natural sciences, 010305 fluids & plasmas, Nuclear physics, chemistry, Electric field, 0103 physical sciences, Cathode ray, 010306 general physics, Beam (structure)
Abstract: For ITER-relevant runaway electron studies, such as suppression, mitigation, termination and/or control of a runaway beam, it is important to obtain the runaway electrons after the disruption. In this paper we report on the first discharges achieved with a post-disruptive runaway electron beam, termed a ‘runaway plateau’, in the COMPASS tokamak. The runaway plateau is produced by a massive gas injection of argon. Almost all of the disruptions with runaway electron plateaus occurred during the plasma current ramp-up phase. The Ar injection discharges with and without a runaway plateau were compared for various parameters. Parametrisation of the discharges shows that the COMPASS disruptions fulfil the range of parameters important for runaway plateau occurrence. These parameters include electron density, electric field, disruption speed, effective safety factor, and the maximum current quench electric field. In addition to these typical parameters, the plasma current value just before the massive gas injection proved to be surprisingly important.
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20. Deep neural networks for plasma tomography with applications to JET and COMPASS

Author: J. Denis, M. Tardocchi, Kiptily, M. Koubiti, M. Ghate, R. Michling, G. De Masi, T. Tala, M. Bassan, R. McAdams, S. Dowson, Antoine Merle, Seppo Koivuranta, O. J. Kwon, S. Mahesan, P. Sparapani, A. Malaquias, M. Tsalas, Gennady V. Miloshevsky, M. Vecsei, Michal Stano, E. Lerche, Štefan Matejčík, Piergiorgio Sonato, S. D. Pinches, A. Dal Molin, O. McCormack, B. Colling, F. Mink, Ph. Mertens, P. Drewelow, Nuno Cruz, D. Iglesias, Alessandro Zocco, K. Rathod, S. Collins, F. Koechl, James Buchanan, Andrew West, Francesco Maviglia, E. Stefanikova, David Taylor, B. Graham, T. Lunt, S. Meshchaninov, Arturo Buscarino, G. L. Ravera, Maide Bucolo, J. P. Thomas, S. Foley, B. Wakeling, N. Ashikawa, D. W. Robson, N. J. Conway, V. P. Lo Schiavo, Stefan Buller, Sergey Popovichev, M. Saleem, Jorge Luis Rodriguez, M. Wheatley, Gabriele Croci, Hugo Bufferand, J.F. Artaud, R. C. Felton, O. Kovanda, D. Hepple, K. Dylst, Gabor Szepesi, M. Oberkofler, G.J. van Rooij, N. Teplova, Istvan Cziegler, K. K. Kirov, S. Vartanian, Y. Xue, D. Nina, J. Bernardo, Lorenzo Figini, Guglielmo Rubinacci, Peter Lang, R. Scannell, N. C. Hawkes, P. Denner, Istvan Pusztai, D. D. Carvalho, Salvatore Ventre, A. Lescinskis, Afanasev, C. Hamlyn-Harris, Panagiotis Tolias, R. Vale, T. O'Gorman, S. Lesnoj, I.E. Day, Karol Malinowski, D. Carralero, N. Balshaw, Massimo Angelone, Michaele Freisinger, I. Monakhov, Jesús Vega, Jonathan Citrin, Antti Hakola, H. Patten, P. A. Simmons, Y. Austin, Sehyun Kwak, J. Regana, Rohde, T. Eich, A. Alkseev, R. Lawless, C. G. Elsmore, Fusco, S. Hacquin, S. A. Silburn, A. Fernades, Luigi Fortuna, P. Bunting, R. Sartori, Yuji Hatano, D. Borodin, L. Colas, Daniele Marocco, M. Lennholm, Carlo Sozzi, J. J. Rasmussen, P. McCullen, Tommy Ahlgren, A. Kirschner, Thomas Johnson, M. Rack, Göran Ericsson, Hans Nordman, Jakub Bielecki, P. Merriman, M. Cavedon, G. Hermon, Geert Verdoolaege, K. J. Gibson, Daisuke Nishijima, R. Clarkson, Fuchs, M. Tomes, R. Zagórski, Gerald Pintsuk, W. Higginson, Daniel F. Valcarcel, R. Mooney, K. Dawson, A. Tallargio, T.H. Osborne, P. J. Carvalho, M. Gethins, R. Dux, Pierre Dumortier, G. Urbanczyk, Inessa Bolshakova, R. King, B. Tal, Daniel Tegnered, J. W. Coenen, Leena Aho-Mantila, Eva Belonohy, S. Schmuck, Kai Nordlund, Grégoire Hornung, G. Tvalashvili, M. De Bock, Y. Baranov, G. De Tommasi, A. Urban, L. Forsythe, I. Zychor, J. Dobrashian, E. Clark, Paolo Arena, Alessia Santucci, Ivan Lupelli, S. Nowak, M. Curuia, Jonathan Graves, J. C. Hillesheim, Claudio Verona, Zoita, S. Moon, C. Castaldo, A.V. Stephen, Karl Schmid, A. Sahlberg, C. Di Troia, R. Woodley, L. Garzotti, D. Sandiford, Matthew M. Knight, Juho Leppänen, S. Emery, O. G. Pompilian, M. Goniche, C. Luna, M. Mayer, M. Baruzzo, A. Weckmann, M. Kempenaars, S. Hazel, Fabio Pisano, Claudia Corradino, A. G. Meigs, P. Leichauer, S. Potzel, Stéphane Devaux, C. Piron, G. Saibene, David A Rasmussen, Bruce Lipschultz, A. Di Siena, E. Lazzaro, J. Deane, C. Meadowcroft, C. J. Rapson, K.-D. Zastrow, Ph. Duckworth, Tom Wauters, F. Nabais, T. Goerler, D. Brunetti, R. Ellis, David Moulton, L. Jones, E. Delabie, Anna Salmi, Luciano Bertalot, G. Burroughes, B. Kos, Laurent Marot, Daniel Primetzhofer, I Miron, N. Lam, F. Napoli, S. Rowe, E. Pajuste, Choong-Seock Chang, R.P. Doerner, D. Silvagni, C. Guillemaut, S. Warder, A.J. Thornton, Matthew Carr, A. Dempsey, Jorge Morales, Pramit Dutta, J. L. Herfindal, S. Maruyama, P. Camp, X. Lefebvre, Ye. O. Kazakov, Andrea G. Chiariello, Gabriele Manduchi, Andre Neto, T. Powell, J. Griffiths, José Vicente, C. Barcellona, J. Hobirk, F. Clairet, L. Xiang, Dirk Reiser, H. Bergsåker, I. Duran, G. Giacometti, M. Kalsey, David Tskhakaya, A. Martin de Aguilera, T. Dittmar, Edmund Highcock, I. Uytdenhouwen, S. Soare, Giuseppe Prestopino, L. Chôné, W. Davis, G. De Temmerman, Basiuk, G. Learoyd, C. Guerard, A. Klix, M. Incelli, B. Viola, R. J. Robins, A. Burckhart, W. Leysen, Jochen Linke, M. Oberparleiter, A. Murari, M. Sertoli, S. D. Scott, A. Lazaros, R. Dejarnac, P. Buratti, H.R. Strauss, G. T. A. Huijsmans, Hajime Urano, Justine M. Kent, A. Kallenbach, D. Fagan, D. S. Darrow, Benedikt Geiger, A. Wynn, X. Sáez, B. Beckett, Horacio Fernandes, G. Ferro, B. Alper, George Wilkie, A. Uccello, T.C. Luce, S. Zoletnik, Petrzilka, Fulvio Auriemma, D. Guard, A. Ho, R. Henriques, I. T. Chapman, D. Butcher, Ph. Maquet, C. Crapper, S. Murphy, C. Ham, D. Brennan, S. Knott, Krasilnikov, D. Kogut, Cédric Pardanaud, K. Galazka, Nicolò Marconato, Daniele Bonfiglio, M. Sos, E. Militello-Asp, Nesenevich, Sean Conroy, S. Hall, L. F. Ruchko, L. Laguardia, O. Marchuk, F.P. Orsitto, I. S. Nedzelskiy, Eva Macusova, E. Andersson Sundén, C. Ayres, R. Prakash, C. Giroud, M. Parsons, R. Rodionov, M. Marin, A. P. Vadgama, A. Reed, Jacob Eriksson, P. Macheta, R. Neu, J. Orszagh, L. Gil, Riccardo Maggiora, M. Peterka, P. Devynck, M. Price, J. Likonen, Andrew M. Edwards, P. Dalgliesh, I. Vinyar, Andrea Malizia, A. Brett, Jane Johnston, A. Kappatou, P. Blatchford, B. Lloyd, P. Vincenzi, A. Mauriya, A. Garcia-Carrasco, Z. Stancar, D. B. Gin, Gediminas Stankunas, J. Edwards, Giuseppe Ambrosino, A. Goodyear, M. Lungaroni, M. Gardener, R.A. Pitts, Svetlana V. Ratynskaia, E. Ivings, Marek Rubel, L. Calacci, Ivo S. Carvalho, M. Afzal, M. Gherendi, D. Schworer, C. Watts, A. M. Messiaen, E. Safi, P. David, A. Petre, J. Uljanovs, U. von Toussaint, H. Greuner, D. Del Sarto, A.C.A. Figueiredo, D. Gallart, R. Bilato, M. Enachescu, P. Monaghan, M. S. J. Rainford, A. Boboc, M. Reinhart, Hiroyasu Utoh, B. P. Duval, L. Hackett, M. Halitovs, G. De Dominici, B. Lomanowski, P. Cahyna, Aslanyan, T. May-Smith, M. Richiusa, A. Goussarov, M. Okabayashi, R. Howell, T. Tadic, M. E. Manso, J. F. Rivero-Rodriguez, Wayne Arter, Ivan Calvo, U. Losada, H. Weisen, A. Teplukhina, Marica Rebai, R. Andrews, C. H. A. Hogben, M. Klas, A. E. Shevelev, J. McKehon, F. Reimold, Enrico Zilli, R. Maingi, M.F. Stamp, A. Rakha, H. T. Kim, D. 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F. Nave, Lorella Carraro, N. Fonnesu, Davide Flammini, P. V. Edappala, G. M. D. Hogeweij, K. Krieger, P. Card, G. Poulipoulis, W. Studholme, Didier Mazon, T. Odupitan, D. Young, F. J. Casson, N. Muthusonai, I. Jepu, Olivier Sauter, Dimitri Voltolina, Sara Carcangiu, C. Reux, Irena Ivanova-Stanik, D. Tskhakaya Jun, O. Bogar, E. Viezzer, Shane Cooper, Fabio Villone, Florin Spineanu, H. Doerk, E. Cecil, J. Goff, F. Nespoli, F. Schluck, G. Ciraolo, Jennifer M. Lehmann, Jan Mlynar, H. J. C. Oliver, M. Marinucci, N. Krawczyk, J. Buch, M. Dreval, G. Possnert, C. Angioni, C. P. Lungu, Marco Ariola, S. Breton, Christopher N. Bowman, A. Kundu, J. Mailloux, I. Stepanov, D. Sprada, J. Zacks, G. Ramogida, E. Wolfrum, N.W. Eidietis, A. Pires dos Reis, Barbara Cannas, Robert E. Grove, A. Huber, Giuliana Sias, A. Baron Wiechec, Markus Airila, M. Berry, P. Huynh, R. Kovaldins, R. Bastow, Darren Price, S. Abduallev, P. Tsavalas, N. Aiba, Plyusnin, Ion Tiseanu, James Williams, M. Beckers, M. Weiland, S.N. Gerasimov, Alessandra Fanni, L. D. Horton, T. Xu, L. Joita, N. Reid, D. Zarzoso Fernandez, D. I. Refy, Jerry Hughes, Clarisse Bourdelle, J. E. Boom, G. Hancu, K. M. Aggarwal, F. Crisanti, M. Poradziński, A. Loarte, P. Vallejos Olivares, T. Mrowetz, Teddy Craciunescu, R. Guirlet, M. Valentinuzzi, J. Stephens, J. Stober, Michael Barnes, Isabel L. Nunes, Mario Pillon, P. Batistoni, G. Verona Rinati, Fabio Moro, R. Lucock, R. Olney, Jari Varje, B. Butler, A. Mariani, M. Hamed, Skvara, C. Terry, Larisa Baumane, T. Alarcon, Mike Kotschenreuther, T. M. Biewer, O. Hemming, N. Marcenko, Z. Kollo, B. Slade, J. Garcia, T. R. Blackman, Simone Peruzzo, N. den Harder, S. Ng, P. Siren, K. G. McClements, Rita Lorenzini, Y. Yakovenko, Lorenzo Frassinetti, J. Hawes, A. Kirk, C. Noble, Nicola Bonanomi, Y. Martynova, A.E. Shumack, F. Di Maio, H. R. Koslowski, N. Pomaro, G. Nemtsev, M. I. K. Santala, Richard George, E. Giovannozzi, T. Giegerich, C. Woodley, G. Pucella, D. Hopley, P.J. Knight, Michela Gelfusa, Francesca Poli, G. Petravich, G. Kocsis, S. Lanthaler, J. A. Wilson, D. Coombs, F. Köchl, G. Stables, Silvia Spagnolo, D. Rigamonti, W. Van Renterghem, Mike Dunne, H. Betar, W. Pires de Sa, Stjepko Fazinić, M. Nocente, G. Birkenmeier, L. Avotina, A. Horton, P. Heesterman, Larry R. Baylor, C. Stavrou, L. Appel, Amosov, J. Fessey, J. Flanagan, C. Paz Soldan, G. Kaveney, R. Young, Shimpei Futatani, U. Samm, R. Naish, P. Strand, E. Lascas Neto, S. Wheeler, Daisuke Shiraki, S. P. Hotchin, D. M. Witts, A. Cobalt, C. Waldon, Davide Galassi, I. Jenkins, S. Panja, C. Gurl, A. Lukin, R. Albanese, Andrea Pavone, A. Davies, J. Hawkins, N. Vianello, C. Besiliu, F. Domptail, Bruno Santos, Y. Li, T. Kaltiaisenaho, O. N. Kent, X. Litaudon, B. Lescinskis, M. Faitsch, Otto Asunta, F. Eriksson, Pericoli, M. Beldishevski, G.A. Rattá, C. D. Challis, Z. Ghani, M. Juvonen, A. C. C. Sips, João M. C. Sousa, Boris Breizman, P. Finburg, Henrik Sjöstrand, Slawomir Jednorog, Ewa Kowalska-Strzęciwilk, A. Martin, R. O. Dendy, B. Lepiavko, D. Croft, Goloborod'ko, A. V. Krasilnikov, M. Wischmeier, K. Gal, R. Ragona, Petter Ström, N. Parsons, G. Calabrò, Jean-Stéphane Joly, A. Capat, Linwei Li, T. Nakano, Paulo Rodrigues, L. Moser, João P. S. Bizarro, L. Piron, K. Pepperell, P. Aleynikov, Ambrogio Fasoli, S.-P. Pehkonen, Giuseppe Gorini, C. Taliercio, M. E. Puiatti, J. Svensson, H. R. Wilson, John Wright, S. Wiesen, O. Asztalos, R.V. Budny, A. Withycombe, P. Piovesan, Jonathan Gaspar, B. D. Stevens, P. Trimble, Vinodh Bandaru, F. S. Zaitsev, H. Sheikh, G. F. Matthews, Daniele Carnevale, K. Schoepf, L. McNamee, A. Czarnecka, P. Blanchard, Erik Fransson, J.P. Coad, Daniel Dunai, Carolina Björkas, A. Manzanares, M. Reich, A. Lahtinen, L. Giacomelli, Mirko Salewski, E. de la Cal, T. D. V. Haupt, T.T.C. Jones, M. Anghel, Kyriakos Hizanidis, J. M. Fontdecaba, Huber, A. Shaw, A. Cufar, A. Muraro, M. Clark, A. Meakins, Roland Sabot, A. Owen, K. Valerii, A. L. Esquisabel, Petr Vondracek, Maria Teresa Porfiri, Walid Helou, S. E. Sharapov, D. Terranova, M. Skiba, Konstantina Mergia, Frank Leipold, Francisco L. Tabarés, M. Zerbini, Ken W Bell, Marco Marinelli, Marco Riva, R. Martone, Bobkov, B. Magesh, A. Ash, Parail, M. Hook, Amanda Hubbard, Silvio Ceccuzzi, Ulrich Fischer, G. Liu, Nick Walkden, R. Otin, P. Santa, P. Abreu, Demerdzhiev, Roberto Zanino, T. Spelzini, António J.N. Batista, P. G. Smith, L. Meneses, S. S. Medley, M. J. Mantsinen, K. Vasava, G. Gervasini, Surya K. Pathak, Kristel Crombé, G. Ellwood, P. Raj, Robert Hager, Ch. Linsmeier, C. Stokes, Petra Bilkova, M. Groth, G. Pautasso, C. R. Nobs, S. Sridhar, P. Chmielewski, David Hatch, Luca Boncagni, I. Balboa, C. Stan-Sion, Nobuyuki Asakura, R. McKean, L. Pigatto, João Figueiredo, Roberto Cavazzana, Juri Romazanov, M. Beurskens, C. Christopher Klepper, Maryna Chernyshova, O. Biletskyi, D. Karkinsky, A. Eksaeva, S. Dalley, Pasquale Gaudio, J. Benayas, J. Dankowski, S. Korolczuk, R. Buckingham, F. Parra Diaz, E. Wang, A. Cardinali, J. Naish, R. O. Pavlichenko, Kalle Heinola, Hiroshi Tojo, Miles M. Turner, Brett Chapman, A. Lyssoivan, F. Militello, E. Matveeva, T. Kobuchi, I. Ksiazek, P. Bohm, Cody Jones, W. Yanling, T. Jackson, P. Gohil, D. Alegre, Tim D. Bohm, F. Jaulmes, L. Zakharov, Peter J. Pool, C.G. Lowry, M. Passeri, D. Testa, Igor Lengar, A. Formisano, C. M. Roach, A. Hjalmarsson, A. Drenik, S. Meiter, William Tang, Carlos B. da Silva, Diogo R. Ferreira, P. J. Lomas, M. McHardy, Gunta Kizane, Angela Busse, S. Jachmich, Corneliu Porosnicu, Stanislas Pamela, Yavorskij, Eduardo Alves, Saskia Mordijck, Boniface Nkonga, J. Morris, Dean A. J. Whittaker, S. Ertmer, A. Hollingsworth, T. Barnard, R. Tatali, S. Reynolds, S. Mistry, Sergio Galeani, Torbjörn Hellsten, V.S. Neverov, David Dickinson, T. M. Huddleston, D. Baiao, F. Salzedas, D. Willoughby, M. Tripsky, Emmanuele Peluso, J. R. Harrison, C. Mazzotta, R. Zarins, M. Maslov, X. Bonnin, T. E. Gebhart, S. Fietz, K. Flinders, C. Hidalgo, Yann Corre, Aqsa Shabbir, A. B. Kukushkin, A. Shepherd, M.L. Walker, R. Clay, T. Vasilopoulou, Paolo Innocente, I. H. Coffey, P. Lalousis, Italo Predebon, R. Bravanec, P. Papp, D. Sytnykov, Ewa Pawelec, M. Bernert, G. Corrigan, Lutsenko, M. Romanelli, Gergely Papp, S. Romanelli, R. Salmon, J. Risner, M. T. Ogawa, A. M. Whitehead, E. Fable, H. Dabirikhah, Juan Manuel López, M. Turnyanskiy, A. Baciero, S. Meigh, M. Garcia-Munoz, Massimiliano Mattei, J.-M. Noterdaeme, N. Hamilton, S. Minucci, I Wilson, A. Muir, A. V. Chankin, C. Clements, Matthias Hoelzl, Francesco Romanelli, S. Gee, R. J. E. Smith, P. de Vries, L. Fittill, S. Menmuir, K. Cave-Ayland, P. Curson, Richard Fridström, D. Grist, S. A. Robinson, Rodney Walker, Michael Loughlin, S. Aleiferis, W. Broeckx, Clayton E. Myers, S. F. Smith, D. Harting, W. Zwingmann, F. Binda, Mark R. Gilbert, Rajnikant Makwana, Richard Goulding, D. Van Eester, I. Voitsekhovitch, M. Bowden, I. Kodeli, Tomasz Czarski, Peter Hawkins, S. S. Henderson, M. Koeppen, D. Ricci, Ondrej Ficker, Carl Hellesen, D. Yadikin, Fabio Subba, Luka Snoj, Anthony Laing, E. R. Solano, M. Stephen, P. Staniec, C. Appelbee, M. Newman, Susan Leerink, M. Nicassio, P. P. Pereira Puglia, M. Brombin, Wouter Tierens, C. Perez von Thun, Cédric Boulbe, Ya. I. Kolesnichenko, Taina Kurki-Suonio, S. Hallworth-Cook, R. P. Johnson, B. B. Carvalho, Anna Widdowson, Alessandro Pau, R. Price, B. Gonçalves, D. L. Keeling, Kazantzidis, Michael Fitzgerald, M. Hughes, K. D. Lawson, M. Brix, Raffaele Fresa, Juha Karhunen, S. Esquembri, K. Purahoo, Matthew Reinke, Gerd Meisl, M. Valovic, J. Horacek, D. King, H. Maier, Philipps, Kenji Tanaka, M. Kresina, M. Valisa, L. Omoregie, Gábor Cseh, Seppo Sipilä, Scott W. Mosher, Filippo Sartori, J. Kaniewski, Jan Weiland, Giuseppe Chitarin, Coccorese, A. R. Field, P. Beaumont, Robert Skilton, D. C. Campling, Mitul Abhangi, S. Villari, Roberta Lima Gomes, G. D. Ewart, S. Wray, A. Broslawski, A. Sinha, Roberto Paccagnella, S. Hollis, R. D. Wood, Albert Gutierrez-Milla, E. Jonasson, L.-G. Eriksson, R. Leach, L. W. Packer, M. Vuksic, H. J. Sun, C. Marchetto, Giuseppe Telesca, Dieter Leichtle, S. Cramp, Blaise Faugeras, M. Allinson, Yannis Kominis, R. Normanton, H. J. Leggate, Francesco Ghezzi, T. Schlummer, Tommaso Bolzonella, Jorge Ferreira, M. J. Walsh, C. Day, Philipp Drews, Steven J. Meitner, M. D. J. Bright, Per Petersson, D. L. Hillis, M. Webb, P. Wright, C. F. Maggi, B. Sieglin, A. Farahani, J. Strachan, M. Muraglia, M. Cecconello, F. Durodié, D. Callaghan, J. Waterhouse, R. J. Dumont, Sara Moradi, Patrick J. McCarthy, S. Feng, M. Balden, M. Kaufman, R. Warren, Brian Grierson, Harry M. Meyer, S.C. Bradnam, D. Kinna, A. Krivska, M. Lungu, E. Suchkov, A. Kantor, D. Conka, C. Penot, A. Zarins, Pierre Manas, D. F. Gear, J. Callaghan, L. Barrera Orte, Tomas Markovic, Yu Gao, A. Lunniss, Z. Vizvary, E. Khilkevich, Th. Puetterich, Dmitry Matveev, E. Perelli Cippo, T. Owen, N. Imazawa, A. Silva, H. P. Summers, Norberto Catarino, Roberto Pasqualotto, P. Muscat, K. Keogh, Ricardo Magnus Osorio Galvao, P. Carman, M. Leyland, E. Veshchev, A. de Castro, M. Gruca, D. C. McDonald, L. Moreira, J. W. Banks, Sanjeev Ranjan, N. Sutton, Iris D. Young, Martin Imrisek, W. Zhang, J. K. Blackburn, Moiseenko, A. Parsloe, T. Loarer, D. N. Borba, S.J. Wukitch, D. P. Coster, J. Penzo, Jose Ramon Martin-Solis, P. Mantica, N. Bekris, M. G. O'Mullane, S. E. Dorling, Yunfeng Liang, S. Gulati, Roberto Ambrosino, J. Schweinzer, Cocilovo, D. Douai, M. A. Henderson, T. Suzuki, Gianluca Rubino, A. Peackoc, Yann Camenen, Y. Miyoshi, Ph. Jacquet, H. T. Lambertz, E. Tholerus, C. Sommariva, Prajapati, Yannick Marandet, F. Hasenbeck, Faa Federico Felici, M. Buckley, Kenneth Hammond, Daniele Milanesio, Cristian Ruset, Katsumichi Hoshino, D. Frigione, D. Chandra, I. Borodkina, P. Dinca, S. Brezinsek, J. Stallard, H. G. Esser, Matthew Sibbald, S. Knipe, Jorge Estrela da Silva, Kensaku Kamiya, P. A. Coates, J. C. Giacalone, Alfredo Pironti, Carvalho, D. D., Ferreira, D. R., Carvalho, P. J., Imrisek, M., Mlynar, J., Fernandes, H., and Formisano, A.
Subjects: Computer science, Feature extraction, Image processing, Computerized Tomography (CT) and Computed Radiography (CR), Plasma diagnostics - interferometry, spectroscopy and imaging, 01 natural sciences, Convolutional neural network, 030218 nuclear medicine & medical imaging, 03 medical and health sciences, 0302 clinical medicine, Compass, Plasma diagnostics-interferometry, spectroscopy and imaging, 0103 physical sciences, Computer vision, Instrumentation, Mathematical Physics, Jet (fluid), Contextual image classification, 010308 nuclear & particles physics, business.industry, Cognitive neuroscience of visual object recognition, Plasma diagnostics - interferometry spectroscopy and imaging, Tomography, Artificial intelligence, business, plasma diagnostics - interferometry, spectroscopy and imaging
Abstract: Convolutional neural networks (CNNs) have found applications in many image processing tasks, such as feature extraction, image classification, and object recognition. It has also been shown that the inverse of CNNs, so- called deconvolutional neural networks, can be used for inverse problems such as plasma tomography. In essence, plasma tomography consists in reconstructing the 2D plasma profile on a poloidal cross-section of a fusion device, based on line-integrated measurements from multiple radiation detectors. Since the reconstruction process is computationally intensive, a deconvolutional neural network trained to produce the same results will yield a significant computational speedup, at the expense of a small error which can be assessed using different metrics. In this work, we discuss the design principles behind such networks, including the use of multiple layers, how they can be stacked, and how their dimensions can be tuned according to the number of detectors and the desired tomographic resolution for a given fusion device. We describe the application of such networks at JET and COMPASS, where at JET we use the bolometer system, and at COMPASS we use the soft X-ray diagnostic based on photodiode arrays.
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21. Progress in diagnostics of the COMPASS tokamak

Author: J.P. Gunn, Daniel Dunai, T. Krizsanoczi, Petr Vondracek, Jordan Cavalier, G. Anda, M. Rabinski, E. Matveeva, M. Peterka, E. Gauthier, Tsv K Popov, J. Stöckel, Roberta Lima Gomes, S. Nanobashvili, D. I. Refy, Vladimir Weinzettl, D. Fridrich, Matthias Komm, Josef Havlicek, A. Havranek, Martin Imrisek, M. Varavin, Karol Malinowski, O. Grover, R. Paprok, M. Vlainic, J. Krbec, M. Berta, O. Bogar, Ondrej Ficker, D. Naydenkova, R. Dejarnac, J. Zajac, Martin Hron, J. Adamek, J. Zebrowski, M. Stano, Miglena Dimitrova, Petra Bilkova, S. Zoletnik, G. P. Ermak, M. Sos, P. Hacek, P. Bohm, Jakub Seidl, Radomir Panek, M. Tomes, Tomas Markovic, F. Zacek, A. Podolnik, K. Mitosinkova, Jozef Varju, D. Sarychev, N. Vianello, Jan Mlynar, K. Kovarik, M. Jakubowski, Monica Spolaore, Tiago M. D. Pereira, J. Horacek, A. Devitre, and António Rito Silva
Subjects: Nuclear instruments and methods for hot plasma diagnostics, Plasma confinement, 01 natural sciences, 010305 fluids & plasmas, Runaway electrons, Plasma instability, Physics::Plasma Physics, cameras, 0103 physical sciences, spectroscopy and imaging, Aerospace engineering, 010306 general physics, Instrumentation, tokamak, Mathematical Physics, Thomson scattering, Physics, neutral particle analyzer, COMPASS tokamak, business.industry, Iter tokamak, Magnetic confinement fusion, magnetic diagnostics, diagnostic beam, Plasma diagnostics - interferometry, Physics::Accelerator Physics, neutron detector, Plasma diagnostics - probes, Detector design and construction technologies and materials, business, probes, Cherenkov detector
Abstract: The COMPASS tokamak at IPP Prague is a small-size device with an ITER-relevant plasma geometry and operating in both the Ohmic as well as neutral beam assisted H-modes since 2012. A basic set of diagnostics installed at the beginning of the COMPASS operation has been gradually broadened in type of diagnostics, extended in number of detectors and collected channels and improved by an increased data acquisition speed. In recent years, a significant progress in diagnostic development has been motivated by the improved COMPASS plasma performance and broadening of its scientific programme (L-H transition and pedestal scaling studies, magnetic perturbations, runaway electron control and mitigation, plasma-surface interaction and corresponding heat fluxes, Alfvenic and edge localized mode observations, disruptions, etc.). In this contribution, we describe major upgrades of a broad spectrum of the COMPASS diagnostics and discuss their potential for physical studies. In particular, scrape-off layer plasma diagnostics will be represented by a new concept for microsecond electron temperature and heat flux measurements - we introduce a new set of divertor Langmuir and ball-pen probe arrays, newly constructed probe heads for reciprocating manipulators as well as several types of standalone probes. Among optical tools, an upgraded high-resolution edge Thomson scattering diagnostic for pedestal studies and a set of new visible light and infrared (plasma-surface interaction investigations) cameras will be described. Particle and beam diagnostics will be covered by a neutral particle analyzer, diagnostics on a lithium beam, Cherenkov detectors (for a direct detection of runaway electrons) and neutron detectors. We also present new modifications of the microwave reflectometer for fast edge density profile measurements.
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22. Use of soft x-ray diagnostic on the COMPASS tokamak for investigations of sawteeth crash neighborhood and of plasma position using fast inversion methods

Author: Vladimir Weinzettl, Martin Imrisek, Jan Mlynar, J. R. Pinzon, Ondrej Ficker, T. Odstrcil, Radomir Panek, Michal Odstrcil, C. Ehrlacher, and Martin Hron
Subjects: Physics, Tokamak, COMPASS tokamak, Magnetic confinement fusion, Plasma, Edge (geometry), Computational physics, law.invention, Nuclear physics, Core (optical fiber), law, Position (vector), Plasma diagnostics, Instrumentation
Abstract: The soft x-ray diagnostic is suitable for monitoring plasma activity in the tokamak core, e.g., sawtooth instability. Moreover, spatially resolved measurements can provide information about plasma position and shape, which can supplement magnetic measurements. In this contribution, fast algorithms with the potential for a real-time use are tested on the data from the COMPASS tokamak. In addition, the soft x-ray data are compared with data from other diagnostics in order to discuss possible connection between sawtooth instability on one side and the transition to higher confinement mode, edge localized modes and productions of runaway electrons on the other side.
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23. Comparative analysis and new post-processing methods for plasma tomography at tokamaks

Author: Jan Mlynar, Ondrej Ficker, Martin Imrisek, Paulo Carvalho, J. Svoboda, and Jet contrinutors
Subjects: Tokamak, Materials science, Plasma, 01 natural sciences, 010305 fluids & plasmas, law.invention, Processing methods, law, 0103 physical sciences, Tomography, 010306 general physics, Instrumentation, Mathematical Physics, Biomedical engineering
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23 results on '"Jan Mlynar"'

1. Experimental Runaway Electron Current Estimation in COMPASS Tokamak

2. Dependence on plasma shape and plasma fueling for small edge-localized mode regimes in TCV and ASDEX Upgrade

3. Runaway electron beam stability and decay in COMPASS

4. Tomographic capabilities of the new GEM based SXR diagnostic of WEST

5. Minimum Fisher Tikhonov Regularization Adapted to Real-Time Tomography

6. Design of soft-X-ray tomographic system in WEST using GEM detectors

7. ITER-like current ramps in JET with ILW: experiments, modelling and consequences for ITER

8. Tungsten transport in JET H-mode plasmas in hybrid scenario, experimental observations and modelling

9. ICRF heating in JET during initial operations with the ITER-like wall

10. Ion cyclotron resonance frequency heating in JET during initial operations with the ITER-like wall

11. Unfolding of energies of fusion products from the nuclear activation data at JET

12. Modern numerical methods for plasma tomography optimisation

13. Introducing minimum Fisher regularisation tomography to AXUV and soft x-ray diagnostic systems of the COMPASS tokamak

14. Charged fusion product loss measurements using nuclear activation

15. Design of multi-range tomographic system for transport studies in tokamak plasmas

16. Burning plasma diagnostics for the physics of JET and ITER

17. Overview of TCV results

18. Steady-state fully noninductive operation with electron cyclotron current drive and current profile control in the tokamak à configuration variable (TCV)

19. Post-disruptive runaway electron beams in the COMPASS tokamak

20. Deep neural networks for plasma tomography with applications to JET and COMPASS

21. Progress in diagnostics of the COMPASS tokamak

22. Use of soft x-ray diagnostic on the COMPASS tokamak for investigations of sawteeth crash neighborhood and of plasma position using fast inversion methods

23. Comparative analysis and new post-processing methods for plasma tomography at tokamaks

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23 results on '"Jan Mlynar"'

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