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1. Impact of ICRF on the scrape-off layer and on plasma wall interactions: From present experiments to fusion reactor

Author

V. Bobkov, D. Aguiam, R. Bilato, S. Brezinsek, L. Colas, A. Czarnecka, P. Dumortier, R. Dux, H. Faugel, H. Fünfgelder, Ph. Jacquet, A. Kallenbach, A. Krivska, C.C. Klepper, E. Lerche, Y. Lin, D. Milanesio, R. Maggiora, I. Monakhov, R. Neu, J.-M. Noterdaeme, R. Ochoukov, Th. Pütterich, M. Reinke, W. Tierens, A. Tuccilo, O. Tudisco, D. Van Eester, J. Wright, S. Wukitch, and W. Zhang

Subjects
Nuclear engineering. Atomic power, TK9001-9401
Abstract

Recent achievements in studies of the effects of ICRF (Ion Cyclotron Range of Frequencies) power on the SOL (Scrape-Off Layer) and PWI (Plasma Wall Interactions) in ASDEX Upgrade (AUG), Alcator C-Mod, and JET-ILW are reviewed. Capabilities to diagnose and model the effect of DC biasing and associated impurity production at active antennas and on magnetic field connections to antennas are described. The experiments show that ICRF near-fields can lead not only to E × B convection, but also to modifications of the SOL density, which for Alcator C-Mod are limited to a narrow region near antenna. On the other hand, the SOL density distribution along with impurity sources can be tailored using local gas injection in AUG and JET-ILW with a positive effect on reduction of impurity sources. The technique of RF image current cancellation at antenna limiters was successfully applied in AUG using the 3-strap AUG antenna and extended to the 4-strap Alcator C-Mod field-aligned antenna. Multiple observations confirmed the reduction of the impact of ICRF on the SOL and on total impurity production when the ratio of the power of the central straps to the total antenna power is in the range 0.6

Published
2019
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2. Progress in reducing ICRF-specific impurity release in ASDEX upgrade and JET

Author

V. Bobkov, D. Aguiam, M. Baruzzo, D. Borodin, I. Borodkina, S. Brezinsek, I. Coffey, L. Colas, A. Czarnecka, E. Delabie, P. Dumortier, F. Durodie, R. Dux, H. Faugel, H. Fünfgelder, C. Giroud, M. Goniche, J. Hobirk, A. Herrmann, J. Jacquot, Ph. Jacquet, A. Kallenbach, A. Krivska, C.C. Klepper, E. Lerche, S. Menmuir, D. Milanesio, R. Maggiora, I. Monakhov, F. Nave, R. Neu, J.-M. Noterdaeme, R. Ochoukov, Th. Pütterich, M. Reinke, A. Tuccilo, O. Tudisco, D. Van Eester, Y. Wang, Q. Yang, and W. Zhang

Subjects
Nuclear engineering. Atomic power, TK9001-9401
Abstract

Use of new 3-strap ICRF antennas with all-tungsten (W) limiters in ASDEX Upgrade results in a reduction of the W sources at the antenna limiters and of the W content in the confined plasma by at least a factor of 2 compared to the W-limiter 2-strap antennas used in the past. The reduction is observed with a broad range of plasma shapes. In multiple locations of antenna frame, the limiter W source has a minimum when RF image currents are decreased by cancellation of the RF current contributions of the central and the outer straps. In JET with ITER-like wall, ITER-like antenna produces about 20% less of main chamber radiation and of W content compared to the old A2 antennas. However the effect of the A2 antennas on W content is scattered depending on which antennas are powered. Experiments in JET with trace nitrogen (N2) injection show that a presence of active ICRF antenna close to the midplane injection valve has little effect on the core N content, both in dipole and in -90° phasing. This indicates that the effect of ICRF on impurity transport across the scape-off-layer is small in JET compared to the dominant effect on impurity sources leading to increased impurity levels during ICRF operation. Keywords: ICRF, RF sheath, Three-strap, 3-strap, ASDEX Upgrade, JET, ILW, A2 antenna, ILA, Sputtering

Published
2017
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3. Surface Texture Detection With a New Sub-mm Resolution Flexible Tactile Capacitive Sensor Array for Multimodal Artificial Finger

Author

Eurico Esteves Moreira, Helder Fonseca, Joao Gaspar, J. Fernandes, Sofia Martins, José Alberto Domingues Rodrigues, F. S. Alves, D. Aguiam, Edoardo Sotgiu, Carlos Calaza, Bernardo Pires, and R.A. Dias

Subjects
Materials science, business.industry, Mechanical Engineering, Capacitive sensing, 010401 analytical chemistry, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, 02 engineering and technology, Grating, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, Orientation (vector space), Optoelectronics, Sensitivity (control systems), Electrical and Electronic Engineering, 0210 nano-technology, business, Image resolution, Layer (electronics), Tactile sensor, Microfabrication
Abstract

This work presents a flexible polyimide-based capacitive tactile sensing array with sub-millimeter spatial resolution. The sensor is conceived to be embedded in a multimodal artificial finger to detect and classify the texture morphology of an object’s surface. The proposed tactile sensor comprises a $16\times 16$ array of capacitive sensing units. Each unit is composed of a parallel square electrode pairs ( $340~ {\mu }\text{m}\,\,\times 340~ {\mu }\text{m}$ ) separated by a compressible air cavity and embedded into a flexible polyimide substrate. Standard MEMS microfabrication techniques were used to develop the sensor. The polyimide device was covered with a thin compressible PDMS layer to tune the normal pressure sensitivity and dynamic range (225–430 ${\mu }\text{m}$ thin PDMS layer resulting in 0.23–0.14 fF/kPa). The detection of the surface morphologies of a regular grating stamp for different orientation and a small metallic nut placed on the sensor is demonstrated, showing a 420 ${\mu }\text{m}$ spatial resolution. The proposed sensor represents a novel capacitive tactile sensing device with a sub-mm resolution of human fingertip sensitivity.

Published
2020
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4. Fabrication of a MEMS Micromirror Based on Bulk Silicon Micromachining Combined With Grayscale Lithography

Author

Joao Gaspar, Ines Garcia, D. Aguiam, Marco Martins, Jorge Cabral, Joana D. Santos, Carlos Daniel Araújo Ferreira, R.A. Dias, and Universidade do Minho

Subjects
Bulk micromachining, Lithography, Micromechanical devices, Materials science, Fabrication, Silicon on insulator, 02 engineering and technology, vertically asymmetric electrodes, 01 natural sciences, Bulk-micromachining process, Electrical and Electronic Engineering, Electrodes, MEMS mirror, Microelectromechanical systems, Science & Technology, business.industry, grayscale, Mechanical Engineering, 010401 analytical chemistry, scanner, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Active layer, Resists, Mirrors, Surface micromachining, Resist, Optoelectronics, 0210 nano-technology, business, Actuators
Abstract

A 1D MEMS (Micro-Electro-Mechanical Systems) mirror for LiDAR applications, based on vertically asymmetric comb-drive electrostatic actuators, is presented in this work employing a novel fabrication process. This novel micromachining process combines typical SOI-based bulk micromachining and grayscale lithography, enabling the fabrication of combs actuators with asymmetric heights using a single lithography step in the active layer. With this technique, the fabrication process is simplified, and the overall costs are reduced since the number of required lithography steps decrease. The fabricated mirrors present self-aligned electrodes with a 2.8 mu m gap and asymmetric heights of the movable and the fixed electrodes of 20 mu m and 50 mu m, respectively. These asymmetric actuators are an essential feature for the operation mode of this device, enabling both in resonant and static mode operation. A mirror field of view (FOV) of 54 degrees at 838 Hz was achieved under low-pressure, when resonantly operated, and a FOV of 0.8 degrees in the static mode., This work was supported by the European Structural and Investment Funds in the FEDER Component through the Operational Competitiveness and Internationalization Programme (COMPETE 2020) under Project 037902 (POCI-01-0247-FEDER-037902). The work of Carlos Ferreira was supported by the Fundacao para a Ciencia e Tecnologia (FCT) under Grant PD/BDE/135102/2017. Subject Editor M. Rais-Zadeh.

Published
2020
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5. Progress from ASDEX Upgrade experiments in preparing the physics basis of ITER operation and DEMO scenario development

Author

U. Stroth, D. Aguiam, E. Alessi, C. Angioni, N. Arden, R. Arredondo Parra, V. Artigues, O. Asunta, M. Balden, V. Bandaru, A. Banon-Navarro, K. Behler, A. Bergmann, M. Bergmann, J. Bernardo, M. Bernert, A. Biancalani, R. Bielajew, R. Bilato, G. Birkenmeier, T. Blanken, V. Bobkov, A. Bock, T. Body, T. Bolzonella, N. Bonanomi, A. Bortolon, B. Böswirth, C. Bottereau, A. Bottino, H. van den Brand, M. Brenzke, S. Brezinsek, D. Brida, F. Brochard, C. Bruhn, J. Buchanan, A. Buhler, A. Burckhart, Y. Camenen, B. Cannas, P. Cano Megias, D. Carlton, M. Carr, P. Carvalho, C. Castaldo, M. Cavedon, C. Cazzaniga, C. Challis, A. Chankin, C. Cianfarani, F. Clairet, S. Coda, R. Coelho, J.W. Coenen, L. Colas, G. Conway, S. Costea, D. Coster, T. Cote, A.J. Creely, G. Croci, D.J. Cruz Zabala, G. Cseh, A. Czarnecka, I. Cziegler, O. D’Arcangelo, A. Dal Molin, P. David, C. Day, M. de Baar, P. de Marné, R. Delogu, S. Denk, P. Denner, A. Di Siena, J.J. Dominguez Palacios Durán, D. Dunai, A. Drenik, M. Dreval, R. Drube, M. Dunne, B.P. Duval, R. Dux, T. Eich, S. Elgeti, A. Encheva, K. Engelhardt, B. Erdös, I. Erofeev, B. Esposito, E. Fable, M. Faitsch, U. Fantz, M. Farnik, H. Faugel, F. Felici, O. Ficker, S. Fietz, A. Figueredo, R. Fischer, O. Ford, L. Frassinetti, M. Fröschle, G. Fuchert, J.C. Fuchs, H. Fünfgelder, S. Futatani, K. Galazka, J. Galdon-Quiroga, D. Gallart Escolà, A. Gallo, Y. Gao, S. Garavaglia, M. Garcia Muñoz, B. Geiger, L. Giannone, S. Gibson, L. Gil, E. Giovannozzi, S. Glöggler, M. Gobbin, J. Gonzalez Martin, T. Goodman, G. Gorini, T. Görler, D. Gradic, G. Granucci, A. Gräter, H. Greuner, M. Griener, M. Groth, A. Gude, L. Guimarais, S. Günter, G. Haas, A.H. Hakola, C. Ham, T. Happel, N. den Harder, G. Harrer, J. Harrison, V. Hauer, T. Hayward-Schneider, B. Heinemann, T. Hellsten, S. Henderson, P. Hennequin, A. Herrmann, E. Heyn, F. Hitzler, J. Hobirk, K. Höfler, J.H. Holm, M. Hölzl, C. Hopf, L. Horvath, T. Höschen, A. Houben, A. Hubbard, A. Huber, K. Hunger, V. Igochine, M. Iliasova, T. Ilkei, K. Insulander Björk, C. Ionita-Schrittwieser, I. Ivanova-Stanik, W. Jacob, N. Jaksic, F. Janky, A. Jansen van Vuuren, A. Jardin, F. Jaulmes, F. Jenko, T. Jensen, E. Joffrin, A. Kallenbach, S. Kálvin, M. Kantor, A. Kappatou, O. Kardaun, J. Karhunen, C.-P. Käsemann, S. Kasilov, A. Kendl, W. Kernbichler, E. Khilkevitch, A. Kirk, S. Kjer Hansen, V. Klevarova, G. Kocsis, M. Koleva, M. Komm, M. Kong, A. Krämer-Flecken, K. Krieger, A. Krivska, O. Kudlacek, T. Kurki-Suonio, B. Kurzan, B. Labit, K. Lackner, F. Laggner, A. Lahtinen, P.T. Lang, P. Lauber, N. Leuthold, L. Li, J. Likonen, O. Linder, B. Lipschultz, Y. Liu, A. Lohs, Z. Lu, T. Luda di Cortemiglia, N.C. Luhmann, T. Lunt, A. Lyssoivan, T. Maceina, J. Madsen, A. Magnanimo, H. Maier, J. Mailloux, R. Maingi, O. Maj, E. Maljaars, P. Manas, A. Mancini, A. Manhard, P. Mantica, M. Mantsinen, P. Manz, M. Maraschek, C. Marchetto, L. Marrelli, P. Martin, A. Martitsch, F. Matos, M. Mayer, M.-L. Mayoral, D. Mazon, P.J. McCarthy, R. McDermott, R. Merkel, A. Merle, D. Meshcheriakov, H. Meyer, D. Milanesio, P. Molina Cabrera, F. Monaco, M. Muraca, F. Nabais, V. Naulin, R. Nazikian, R.D. Nem, A. Nemes-Czopf, G. Neu, R. Neu, A.H. Nielsen, S.K. Nielsen, T. Nishizawa, M. Nocente, J.-M. Noterdaeme, I. Novikau, S. Nowak, M. Oberkofler, R. Ochoukov, J. Olsen, F. Orain, F. Palermo, O. Pan, G. Papp, I. Paradela Perez, A. Pau, G. Pautasso, C. Paz-Soldan, P. Petersson, P. Piovesan, C. Piron, U. Plank, B. Plaum, B. Plöck, V. Plyusnin, G. Pokol, E. Poli, L. Porte, T. Pütterich, M. Ramisch, J. Rasmussen, G. Ratta, S. Ratynskaia, G. Raupp, D. Réfy, M. Reich, F. Reimold, D. Reiser, M. Reisner, D. Reiter, T. Ribeiro, R. Riedl, J. Riesch, D. Rittich, J.F. Rivero Rodriguez, G. Rocchi, P. Rodriguez-Fernandez, M. Rodriguez-Ramos, V. Rohde, G. Ronchi, A. Ross, M. Rott, M. Rubel, D.A. Ryan, F. Ryter, S. Saarelma, M. Salewski, A. Salmi, O. Samoylov, L. Sanchis Sanchez, J. Santos, O. Sauter, G. Schall, K. Schlüter, K. Schmid, O. Schmitz, P.A. Schneider, R. Schrittwieser, M. Schubert, C. Schuster, T. Schwarz-Selinger, J. Schweinzer, E. Seliunin, A. Shabbir, A. Shalpegin, S. Sharapov, U. Sheikh, A. Shevelev, G. Sias, M. Siccinio, B. Sieglin, A. Sigalov, A. Silva, C. Silva, D. Silvagni, J. Simpson, S. Sipilä, E. Smigelskis, A. Snicker, E. Solano, C. Sommariva, C. Sozzi, G. Spizzo, M. Spolaore, A. Stegmeir, M. Stejner, J. Stober, E. Strumberge, G. Suarez Lopez, H.-J. Sun, W. Suttrop, E. Sytova, T. Szepesi, B. Tál, T. Tala, G. Tardini, M. Tardocchi, D. Terranova, M. Teschke, E. Thorén, W. Tierens, D. Told, W. Treutterer, G. Trevisan, E. Trier, M. Tripský, M. Usoltceva, M. Valisa, M. Valovic, M. van Zeeland, F. Vannini, B. Vanovac, P. Varela, S. Varoutis, N. Vianello, J. Vicente, G. Verdoolaege, T. Vierle, E. Viezzer, I. Voitsekhovitch, U. von Toussaint, D. Wagner, X. Wang, M. Weiland, A.E. White, M. Willensdorfer, B. Wiringer, M. Wischmeier, R. Wolf, E. Wolfrum, Q. Yang, Q. Yu, R. Zagórski, I. Zammuto, T. Zehetbauer, W. Zhang, W. Zholobenko, M. Zilker, A. Zito, H. Zohm, S. Zoletnik, the EUROfusion MST1 Team, 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), Aix Marseille Université (AMU), Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), EUROfusion MST1 Team, Barcelona Supercomputing Center, Department of Applied Physics, Aalto-yliopisto, Aalto University, Stroth, U, Aguiam, D, Alessi, E, Angioni, C, Arden, N, Parra, R, Artigues, V, Asunta, O, Balden, M, Bandaru, V, Banon-Navarro, A, Behler, K, Bergmann, A, Bergmann, M, Bernardo, J, Bernert, M, Biancalani, A, Bielajew, R, Bilato, R, Birkenmeier, G, Blanken, T, Bobkov, V, Bock, A, Body, T, Bolzonella, T, Bonanomi, N, Bortolon, A, Boswirth, B, Bottereau, C, Bottino, A, Van Den Brand, H, Brenzke, M, Brezinsek, S, Brida, D, Brochard, F, Bruhn, C, Buchanan, J, Buhler, A, Burckhart, A, Camenen, Y, Cannas, B, Megias, P, Carlton, D, Carr, M, Carvalho, P, Castaldo, C, Cavedon, M, Cazzaniga, C, Challis, C, Chankin, A, Cianfarani, C, Clairet, F, Coda, S, Coelho, R, Coenen, J, Colas, L, Conway, G, Costea, S, Coster, D, Cote, T, Creely, A, Croci, G, Zabala, D, Cseh, G, Czarnecka, A, Cziegler, I, D'Arcangelo, O, Molin, A, David, P, Day, C, De Baar, M, De Marne, P, Delogu, R, Denk, S, Denner, P, Di Siena, A, Palacios Duran, J, Dunai, D, Drenik, A, Dreval, M, Drube, R, Dunne, M, Duval, B, Dux, R, Eich, T, Elgeti, S, Encheva, A, Engelhardt, K, Erdos, B, Erofeev, I, Esposito, B, Fable, E, Faitsch, M, Fantz, U, Farnik, M, Faugel, H, Felici, F, Ficker, O, Fietz, S, Figueredo, A, Fischer, R, Ford, O, Frassinetti, L, Froschle, M, Fuchert, G, Fuchs, J, Funfgelder, H, Futatani, S, Galazka, K, Galdon-Quiroga, J, Escola, D, Gallo, A, Gao, Y, Garavaglia, S, Munoz, M, Geiger, B, Giannone, L, Gibson, S, Gil, L, Giovannozzi, E, Gloggler, S, Gobbin, M, Martin, J, Goodman, T, Gorini, G, Gorler, T, Gradic, D, Granucci, G, Grater, A, Greuner, H, Griener, M, Groth, M, Gude, A, Guimarais, L, Gunter, S, Haas, G, Hakola, A, Ham, C, Happel, T, Den Harder, N, Harrer, G, Harrison, J, Hauer, V, Hayward-Schneider, T, Heinemann, B, Hellsten, T, Henderson, S, Hennequin, P, Herrmann, A, Heyn, E, Hitzler, F, Hobirk, J, Hofler, K, Holm, J, Holzl, M, Hopf, C, Horvath, L, Hoschen, T, Houben, A, Hubbard, A, Huber, A, Hunger, K, Igochine, V, Iliasova, M, Ilkei, T, Bjork, K, Ionita-Schrittwieser, C, Ivanova-Stanik, I, Jacob, W, Jaksic, N, Janky, F, Jansen Van Vuuren, A, Jardin, A, Jaulmes, F, Jenko, F, Jensen, T, Joffrin, E, Kallenbach, A, Kalvin, S, Kantor, M, Kappatou, A, Kardaun, O, Karhunen, J, Kasemann, C, Kasilov, S, Kendl, A, Kernbichler, W, Khilkevitch, E, Kirk, A, Hansen, S, Klevarova, V, Kocsis, G, Koleva, M, Komm, M, Kong, M, Kramer-Flecken, A, Krieger, K, Krivska, A, Kudlacek, O, Kurki-Suonio, T, Kurzan, B, Labit, B, Lackner, K, Laggner, F, Lahtinen, A, Lang, P, Lauber, P, Leuthold, N, Li, L, Likonen, J, Linder, O, Lipschultz, B, Liu, Y, Lohs, A, Lu, Z, Luda Di Cortemiglia, T, Luhmann, N, Lunt, T, Lyssoivan, A, Maceina, T, Madsen, J, Magnanimo, A, Maier, H, Mailloux, J, Maingi, R, Maj, O, Maljaars, E, Manas, P, Mancini, A, Manhard, A, Mantica, P, Mantsinen, M, Manz, P, Maraschek, M, Marchetto, C, Marrelli, L, Martin, P, Martitsch, A, Matos, F, Mayer, M, Mayoral, M, Mazon, D, Mccarthy, P, Mcdermott, R, Merkel, R, Merle, A, Meshcheriakov, D, Meyer, H, Milanesio, D, Cabrera, P, Monaco, F, Muraca, M, Nabais, F, Naulin, V, Nazikian, R, Nem, R, Nemes-Czopf, A, Neu, G, Neu, R, Nielsen, A, Nielsen, S, Nishizawa, T, Nocente, M, Noterdaeme, J, Novikau, I, Nowak, S, Oberkofler, M, Ochoukov, R, Olsen, J, Orain, F, Palermo, F, Pan, O, Papp, G, Perez, I, Pau, A, Pautasso, G, Paz-Soldan, C, Petersson, P, Piovesan, P, Piron, C, Plank, U, Plaum, B, Plock, B, Plyusnin, V, Pokol, G, Poli, E, Porte, L, Putterich, T, Ramisch, M, Rasmussen, J, Ratta, G, Ratynskaia, S, Raupp, G, Refy, D, Reich, M, Reimold, F, Reiser, D, Reisner, M, Reiter, D, Ribeiro, T, Riedl, R, Riesch, J, Rittich, D, Rodriguez, J, Rocchi, G, Rodriguez-Fernandez, P, Rodriguez-Ramos, M, Rohde, V, Ronchi, G, Ross, A, Rott, M, Rubel, M, Ryan, D, Ryter, F, Saarelma, S, Salewski, M, Salmi, A, Samoylov, O, Sanchez, L, Santos, J, Sauter, O, Schall, G, Schluter, K, Schmid, K, Schmitz, O, Schneider, P, Schrittwieser, R, Schubert, M, Schuster, C, Schwarz-Selinger, T, Schweinzer, J, Seliunin, E, Shabbir, A, Shalpegin, A, Sharapov, S, Sheikh, U, Shevelev, A, Sias, G, Siccinio, M, Sieglin, B, Sigalov, A, Silva, A, Silva, C, Silvagni, D, Simpson, J, Sipila, S, Smigelskis, E, Snicker, A, Solano, E, Sommariva, C, Sozzi, C, Spizzo, G, Spolaore, M, Stegmeir, A, Stejner, M, Stober, J, Strumberge, E, Lopez, G, Sun, H, Suttrop, W, Sytova, E, Szepesi, T, Tal, B, Tala, T, Tardini, G, Tardocchi, M, Terranova, D, Teschke, M, Thoren, E, Tierens, W, Told, D, Treutterer, W, Trevisan, G, Trier, E, Tripsky, M, Usoltceva, M, Valisa, M, Valovic, M, Van Zeeland, M, Vannini, F, Vanovac, B, Varela, P, Varoutis, S, Vianello, N, Vicente, J, Verdoolaege, G, Vierle, T, Viezzer, E, Voitsekhovitch, I, Von Toussaint, U, Wagner, D, Wang, X, Weiland, M, White, A, Willensdorfer, M, Wiringer, B, Wischmeier, M, Wolf, R, Wolfrum, E, Yang, Q, Yu, Q, Zagorski, R, Zammuto, I, Zehetbauer, T, Zhang, W, Zholobenko, W, Zilker, M, Zito, A, Zohm, H, and Zoletnik, S

Subjects
Nuclear and High Energy Physics, Asdex Upgrade, confinement, ELLM-free discharges, sol, Computer science, Nuclear engineering, ALCATOR C-MOD, UPPER DIVERTOR, ASDEX Upgrade, Physics::Plasma Physics, [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], Simulació per ordinador, alcator c-mod, ddc:530, upper divertor, ELLM-free discharge, SOL, Basis (linear algebra), Physics, turbulence, transition, h-mode plasmas, Condensed Matter Physics, ddc, Informàtica::Aplicacions de la informàtica::Aplicacions informàtiques a la física i l‘enginyeria [Àrees temàtiques de la UPC], Fusion reactors, Physics and Astronomy, CONFINEMENT MODES, H-MODE PLASMAS, Physics::Space Physics, Nuclear fusion, TURBULENCE, ddc:620, confinement modes, TRANSITION
Abstract

An overview of recent results obtained at the tokamak ASDEX Upgrade (AUG) is given. A work flow for predictive profile modelling of AUG discharges was established which is able to reproduce experimental H-mode plasma profiles based on engineering parameters only. In the plasma center, theoretical predictions on plasma current redistribution by a dynamo effect were confirmed experimentally. For core transport, the stabilizing effect of fast ion distributions on turbulent transport is shown to be important to explain the core isotope effect and improves the description of hollow low-Z impurity profiles. The L–H power threshold of hydrogen plasmas is not affected by small helium admixtures and it increases continuously from the deuterium to the hydrogen level when the hydrogen concentration is raised from 0 to 100%. One focus of recent campaigns was the search for a fusion relevant integrated plasma scenario without large edge localised modes (ELMs). Results from six different ELM-free confinement regimes are compared with respect to reactor relevance: ELM suppression by magnetic perturbation coils could be attributed to toroidally asymmetric turbulent fluctuations in the vicinity of the separatrix. Stable improved confinement mode plasma phases with a detached inner divertor were obtained using a feedback control of the plasma β. The enhanced Dα H-mode regime was extended to higher heating power by feedback controlled radiative cooling with argon. The quasi-coherent exhaust regime was developed into an integrated scenario at high heating power and energy confinement, with a detached divertor and without large ELMs. Small ELMs close to the separatrix lead to peeling-ballooning stability and quasi continuous power exhaust. Helium beam density fluctuation measurements confirm that transport close to the separatrix is important to achieve the different ELM-free regimes. Based on separatrix plasma parameters and interchange-drift-Alfvén turbulence, an analytic model was derived that reproduces the experimentally found important operational boundaries of the density limit and between L- and H-mode confinement. Feedback control for the X-point radiator (XPR) position was established as an important element for divertor detachment control. Stable and detached ELM-free phases with H-mode confinement quality were obtained when the XPR was moved 10 cm above the X-point. Investigations of the plasma in the future flexible snow-flake divertor of AUG by means of first SOLPS-ITER simulations with drifts activated predict beneficial detachment properties and the activation of an additional strike point by the drifts. This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014–2018 and 2019–2020 under Grant Agreement No. 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission. Peer Reviewed "Article signat per més de 50 autors/es: U. Stroth, D. Aguiam, E. Alessi, C. Angioni, N. Arden, R. Arredondo Parra, V. Artigues, O. Asunta, M. Balden, V. Bandaru, A. Banon-Navarro, K. Behler, A. Bergmann, M. Bergmann, J. Bernardo, M. Bernert, A. Biancalani, R. Bielajew, R. Bilato, G. Birkenmeier, T. Blanken, V. Bobkov, A. Bock, T. Body, T. Bolzonella, N. Bonanomi, A. Bortolon, B. Böswirth, C. Bottereau, A. Bottino, H. van den Brand, M. Brenzke, S. Brezinsek, D. Brida, F. Brochard, C. Bruhn, J. Buchanan, A. Buhler, A. Burckhart, Y. Camenen, B. Cannas, P. Cano Megias, D. Carlton, M. Carr, P. Carvalho, C. Castaldo, M. Cavedon, C. Cazzaniga, C. Challis, A. Chankin, C. Cianfarani, F. Clairet, S. Coda, R. Coelho, J.W. Coenen, L. Colas, G. Conway, S. Costea, D. Coster, T. Cote, A.J. Creely, G. Croci, D.J. Cruz Zabala, G. Cseh, A. Czarnecka, I. Cziegler, O. D'Arcangelo, A. Dal Molin, P. David, C. Day, M. de Baar, P. de Marné, R. Delogu, S. Denk, P. Denner, A. Di Siena, J.J. Dominguez Palacios Durán, D. Dunai, A. Drenik, M. Dreval, R. Drube, M. Dunne, B.P. Duval, R. Dux, T. Eich, S. Elgeti, A. Encheva, K. Engelhardt, B. Erdös, I. Erofeev, B. Esposito, E. Fable, M. Faitsch, U. Fantz, M. Farnik, H. Faugel, F. Felici, O. Ficker, S. Fietz, A. Figueredo, R. Fischer, O. Ford, L. Frassinetti, M. Fröschle, G. Fuchert, J.C. Fuchs, H. Fünfgelder, S. Futatani, K. Galazka, J. Galdon-Quiroga, D. Gallart Escolà, A. Gallo10, Y. Gao11, S. Garavaglia3, M. Garcia Muñoz16, B. Geiger21, L. Giannone1, S. Gibson32, L. Gil2, E. Giovannozzi18, S. Glöggler1, M. Gobbin8, J. Gonzalez Martin, T. Goodman, G. Gorini, T. Görler, D. Gradic, G. Granucci, A. Gräter, H. Greuner, M. Griener, M. Groth, A. Gude, L. Guimarais, S. Günter, G. Haas, A.H. Hakola, C. Ham, T. Happel, N. den Harder, G. Harrer, J. Harrison, V. Hauer, T. Hayward-Schneider, B. Heinemann, T. Hellsten, S. Henderson, P. Hennequin, A. Herrmann, E. Heyn, F. Hitzler, J. Hobirk, K. Höfler, J.H. Holm, M. Hölzl, C. Hopf, L. Horvath, T. Höschen, A. Houben, A. Hubbard, A. Huber, K. Hunger, V. Igochine, M. Iliasova, T. Ilkei, K. Insulander Björk, C. Ionita-Schrittwieser, I. Ivanova-Stanik, W. Jacob, N. Jaksic, F. Janky, A. Jansen van Vuuren, A. Jardin, F. Jaulmes, F. Jenko, T. Jensen, E. Joffrin, A. Kallenbach, S. Kálvin, M. Kantor, A. Kappatou, O. Kardaun, J. Karhunen4, C.-P. Käsemann, S. Kasilov, A. Kendl, W. Kernbichler, E. Khilkevitch, A. Kirk, S. Kjer Hansen, V. Klevarova, G. Kocsis, M. Koleva, M. Komm, M. Kong, A. Krämer-Flecken, K. Krieger, A. Krivska, O. Kudlacek, T. Kurki-Suonio, B. Kurzan, B. Labit, K. Lackner, F. Laggner, A. Lahtinen, P.T. Lang, P. Lauber, N. Leuthold, L. Li, J. Likonen, O. Linder, B. Lipschultz, Y. Liu, A. Lohs, Z. Lu, T. Luda di Cortemiglia, N.C. Luhmann, T. Lunt, A. Lyssoivan, T. Maceina, J. Madsen, A. Magnanimo, H. Maier, J. Mailloux, R. Maingi, O. Maj, E. Maljaars, P. Manas, A. Mancini, A. Manhard, P. Mantica, M. Mantsinen, P. Manz, M. Maraschek, C. Marchetto, L. Marrelli, P. Martin, A. Martitsch, F. Matos, M. Mayer, M.-L. Mayoral, D. Mazon, P.J. McCarthy, R. McDermott, R. Merkel, A. Merle, D. Meshcheriakov, H. Meyer, D. Milanesio, P. Molina Cabrera, F. Monaco, M. Muraca, F. Nabais, V. Naulin, R. Nazikian, R.D. Nem, A. Nemes-Czopf, G. Neu, R. Neu, A.H. Nielsen, S.K. Nielsen, T. Nishizawa, M. Nocente, J.-M. Noterdaeme, I. Novikau, S. Nowak, M. Oberkofler, R. Ochoukov, J. Olsen, F. Orain, F. Palermo, O. Pan, G. Papp, I. Paradela Perez, A. Pau, G. Pautasso, C. Paz-Soldan, P. Petersson, P. Piovesan, C. Piron, U. Plank, B. Plaum, B. Plöck, V. Plyusnin, G. Pokol, E. Poli, L. Porte, T. Pütterich, M. Ramisch, J. Rasmussen, G. Ratta, S. Ratynskaia, G. Raupp, D. Réfy, M. Reich1, F. Reimold, D. Reiser, M. Reisner, D. Reiter, T. Ribeiro, R. Riedl, J. Riesch, D. Rittich, J.F. Rivero Rodriguez, G. Rocchi, P. Rodriguez-Fernandez, M. Rodriguez-Ramos, V. Rohde, G. Ronchi, A. Ross, M. Rott, M. Rubel, D.A. Ryan, F. Ryter, S. Saarelma, M. Salewski, A. Salmi, O. Samoylov, L. Sanchis Sanchez, J. Santos, O. Sauter, G. Schall, K. Schlüter, K. Schmid, O. Schmitz, P.A. Schneider, R. Schrittwieser, M. Schubert, C. Schuster, T. Schwarz-Selinger, J. Schweinzer, E. Seliunin, A. Shabbir, A. Shalpegin, S. Sharapov, U. Sheikh, A. Shevelev, G. Sias, M. Siccinio, B. Sieglin, A. Sigalov, A. Silva, C. Silva, D. Silvagni, J. Simpson, S. Sipilä, E. Smigelskis, A. Snicker, E. Solano, C. Sommariva, C. Sozzi, G. Spizzo, M. Spolaore, A. Stegmeir, M. Stejner, J. Stober, E. Strumberge1, G. Suarez Lopez, H.-J. Sun, W. Suttrop, E. Sytova, T. Szepesi, B. Tál, T. Tala, G. Tardini, M. Tardocchi, D. Terranova, M. Teschke, E. Thorén, W. Tierens, D. Told, W. Treutterer, G. Trevisan, E. Trier, M. Tripský, M. Usoltceva, M. Valisa, M. Valovic, M. van Zeeland, F. Vannini, B. Vanovac, P. Varela, S. Varoutis, N. Vianello, J. Vicente, G. Verdoolaege, T. Vierle, E. Viezzer, I. Voitsekhovitch, U. von Toussaint, D. Wagner, X. Wang, M. Weiland, A.E. White, M. Willensdorfer, B. Wiringer, M. Wischmeier, R. Wolf, E. Wolfrum, Q. Yang, Q. Yu, R. Zagórski, I. Zammuto, T. Zehetbauer, W. Zhang, W. Zholobenko, M. Zilker, A. Zito, H. Zohm, S. Zoletnik and the EUROfusion MST1 Team "

Published
2022
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6. Enhanced virtual reality application with tactile feedback for prototyping in-car dashboard surfaces

Author

Nuno Sousa, Rosane Sampaio, Edoardo Sotgiu, D. Aguiam, Alar Ainla, Joao Gaspar, Marcelo Pires, Gabriel Ribeiro, Joana Vieira, and Emanuel Sousa

Subjects
Human–computer interaction, Computer science, Virtual reality, Haptic perception, Tactile sensor, ComputingMethodologies_COMPUTERGRAPHICS, Haptic technology, Visualization
Abstract

Product-in-Touch is an ongoing R&D project for developing a virtual reality application for prototyping in-car textures, providing both visual and haptic input to a user. The device will allow designers to virtually prototype textured surfaces, both in terms of visual and haptic perception, without the need for physical prototypes.

Published
2021
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7. Industry 4.0: Real-time monitoring of an injection molding tool for smart predictive maintenance

Author

Joao Gaspar, Eurico Esteves Moreira, Elisabete P. Fernandes, Edoardo Sotgiu, F. S. Alves, D. Aguiam, Antonio Pina, Gabriel Ribeiro, and Marco Martins

Subjects
0209 industrial biotechnology, Industry 4.0, Computer science, 020208 electrical & electronic engineering, Control (management), Process (computing), 02 engineering and technology, Molding (process), Pressure sensor, Predictive maintenance, Reliability engineering, Molding (decorative), 020901 industrial engineering & automation, 0202 electrical engineering, electronic engineering, information engineering
Abstract

Predictive maintenance has been growing as one of the main topics of the Industry 4.0 concept and several challenges arise from it. The constant search for mechanisms that allow the control and reduction of machine down-time led to the study of new ways of extracting valuable information from injection tools through the monitorization of different parameters. In the study presented here, a custom pressure sensor is integrated into an injection tool to monitor the different pressure levels along the process cycle, together with a commercial off-the-shelf accelerometer, coupled at the surface of the tool. Both sensors recorded the events over regular productive cycles, being this information, in the long-term, paramount for a smart predictive maintenance. The runtime information can also give valuable insights about the tool condition in real-time.

Published
2020
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8. X-mode raw data analysis of the new AUG ICRF antenna edge density profile reflectometer

Author

L. Guimarais, H. Fünfgelder, J. M. Santos, Roberto Cavazzana, G. De Masi, L. Fattorini, A. Silva, L. Meneses, P. J. Carvalho, Ocleto D'Arcangelo, Ana Fernandes, Helmut Faugel, J.-M. Noterdaeme, D. Aguiam, A. A. Tuccillo, R. C. Pereira, G. D. Conway, V. Bobkov, G. Rocchi, P. F. Carvalho, O. Tudisco, B. Gonçalves, and ASDEX Upgrade Team, Max Planck Institute for Plasma Physics, Max Planck Society

Subjects
010302 applied physics, Physics, business.industry, Mechanical Engineering, Detector, Plasma, 01 natural sciences, 010305 fluids & plasmas, Amplitude, Optics, Nuclear Energy and Engineering, ASDEX Upgrade, 0103 physical sciences, Demodulation, General Materials Science, Plasma diagnostics, Reflectometry, business, Microwave, Civil and Structural Engineering
Abstract

The new multichannel X-mode reflectometer installed on ASDEX Upgrade measures the plasma density profile evolution at different positions in front of the ICRF antenna. The reflectometer operates in the extended U-band (40–68 GHz) microwave region, measuring density profiles up to 2 × 1019 m−3 with magnetic fields between 1.5 T and 2.7 T. In this heterodyne reflectometer architecture, the signal reflected by the plasma is down-shifted and quadrature detectors demodulate its in-phase and quadrature (IQ) components. In this work we analysed the acquired IQ signals from the different reflectometer antennas, and describe the waveguide dispersion calibration and filtering of the raw signal. The effect of spurious reflections, such as the multiple reflections from the ICRF antenna metal straps, are analysed and taken into account on the data processing software. In high plasma density and high magnetic field scenarios, both the lower and upper X-mode cut off frequencies are detected in the probing range. The first fringe (FF) reflection of the upper cut off indicates the start of the plasma signal and must be determined robustly to reduce density profile errors. Existing FF estimation algorithms based on signal amplitude and spectral information may still fail in the presence of both upper and lower cut off reflections.

Published
2017
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9. 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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10. Heterodyning based portable instrument for eddy currents non-destructive testing

Author

Moisés Piedade, Luis S. Rosado, D. Aguiam, and Pedro M. Ramos

Subjects
Engineering, Digital signal processor, Signal generator, business.industry, Applied Mathematics, Electrical engineering, USB, Condensed Matter Physics, Signal, law.invention, law, Nondestructive testing, Operational transconductance amplifier, Eddy current, Electronic engineering, Electrical and Electronic Engineering, business, Instrumentation, Digital signal processing
Abstract

The development and implementation of a portable eddy currents testing instrument with heterodyning based measurements is presented in this paper. The instrument is composed by a dedicated electronic measurement circuitry embedded inside a rugged tablet computer for control and visualization and that interfaces a small footprint planar eddy currents probe. A DDS waveform generator and a transconductance amplifier are used to drive the probe current. The probe output voltage is amplified up to 60 dB and down-converted to an intermediary frequency, which is then digitized. IQ demodulation of the digitized signal is used to obtain the real and imaginary components of the probe output and is computed in real time by the embedded digital signal processor and transmitted to the host computer by USB. The eddy currents testing instrument can be operated as a battery powered standalone device with post-processing and visualization capabilities which can be modified for specific applications without the need for hardware modifications. The system architecture, electrical characterization of the analog circuit, digital signal processing and visualization interface are described. The eddy currents inspection results of an aluminum sample with synthetic defects and friction stir welding joint samples, using this instrument are presented.

Published
2015
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11. SOL Transport and Filamentary Dynamics in High Density Tokamak Regimes

Author

Vianello N., D. Carralero, C. K. Tsui, V. Naulin, M. Agostini, J. Boedo, B. Labit, C. Theiler, D. Aguiam, S. Allan, M. Bernert, S. Costea, I. Cziegler, H. De Oliveira, J. Galdon-Quiroga, G. Grenfell, A. Hakola, C. Ionita, H. Isliker, A. Karpushov, J. Kovacic, B. Lipschultz, R. Maurizio, K. McClements, F. Militello, J. Olsen, J.J. Rasmussen, T. Ravensbergen, H. Reimerdes, B. Schneider, R. Schrittwieser, M. Spolaore, K. Verhaegh, J. Vicente, N. Walkden, W. Zhang, E. Wolfrum, the ASDEX-Upgrade Team, the TCV team, and the EUROfusion MST1 Team

Subjects
High Density Tokamak Regimes, SOL Transport and Filamentary Dynamics, SOL, scrape off layer
Abstract

Addressing the role of scrape off layer filamentary transport is a subject of intense studies in fusion science. Intermittent structures dominate transport in L-Mode and strongly contribute to particle and energy losses in H-mode. The role of convective radial losses has become even more important due to its contribution to the shoulder formation in L-Mode, describing the progressive flattening of the density scrape off layer profile at high density r1- 3s. Investigation of this process revealed the strong relationship between divertor conditions and the upstream profiles, mediated by filaments dynamics which varies according to the downstream conditions. Preliminary investigations suggested that similar mechanisms occur in H-Mode r1s and that filaments contribute the SOL transport in H-mode density limit (HDL) as well r4s. The present contribution will report on results obtained on ASDEXUpgrade and TCV tokamaks, to address the role of filamentary transport in high density regimes both in L- and H-Mode. The combined results enlarge the operational space, from a device with a closed divertor, metallic first wall and cryogenic pumping system to a carbon machine with a completely open divertor. The mechanism of shoulder formation and the role of filaments have been tested against variation of plasma current, magnetic configuration (single and double null plasmas), and divertor neutral densities, through modification of cryopump efficiency. At constant magnetic field the density decay length increases with filament-size independently of the plasma current for both machines in L-mode, consistently with the fact that upstream profiles and divertor neutral pressure exhibit the same trend with normalized Greenwald fraction.

Published
2018

12. ICRF coupling in ASDEX upgrade magnetically perturbed 3D plasmas

Author

H. Zohm, V. Bobkov, G. Birkenmeier, L. Guimarais, H. Fünfgelder, G. Suarez Lopez, R. M. McDermott, E. Seliunin, M. Cavedon, R. Ochoukov, J.-M. Noterdaeme, W. Suttrop, Helmut Faugel, D. Aguiam, Wouter Tierens, M. G. Dunne, R. Fischer, M. Willensdorfer, Lopez, G, Ochoukov, R, Tierens, W, Willensdorfer, M, Zohm, H, Aguiam, D, Birkenmeier, G, Bobkov, V, Cavedon, M, Dunne, M, Faugel, H, Fischer, R, Funfgelder, H, Guimarais, L, Mcdermott, R, Noterdaeme, J, Seliunin, E, Suttrop, W, ASDEX Upgrade Team, Max Planck Institute for Plasma Physics, Max Planck Society, and EUROfusion MST1 Team

Subjects
Physics, Coupling, ICRF, MP, Plasma, Condensed Matter Physics, 01 natural sciences, 010305 fluids & plasmas, Nuclear Energy and Engineering, ASDEX Upgrade, 0103 physical sciences, coupling, Atomic physics, 010306 general physics
Abstract

The RF properties of the four ion cyclotron range of frequencies (ICRF) antennas in the ASDEX Upgrade tokamak are characterized in H-mode magnetically perturbed 3D discharges. An n = 2 magnetic perturbation (MP) field is applied and rigidly rotated, which allows diagnosing the separatrix displacement and consequent coupling change. We find the antenna loading resistance to be coherently modified by the resulting non-axisymmetric plasma equilibria, thus becoming a function of the applied MP field poloidal mode spectra. We perform a detailed statistical analysis, which correlates the change in loading resistance to the fast wave R-cutoff layer movements. From it, a 1D scaling is derived that differs from previous studies evaluated in pure axisymmetric plasma conditions. This experimentally derived scaling is used to predict the average loading resistance change of the ITER ICRF antenna under applied MPs. ICRF coupling simulations using measured 1D density profiles are performed with the RAPLICASOL code, in order to investigate the predictive capabilities of numerical state of the art tools. We find that both 1D conventional scaling laws and 1D numerical simulations fail to capture the 3D physics, and can substantially overestimate the measured loading resistance change up to a factor of ∼3.

Published
2019
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13. Recent progress on improving ICRF coupling and reducing RF-specific impurities in ASDEX Upgrade

Author

T. Lunt, Wei Zhang, Qingxi Yang, António Rito Silva, A. Kostic, D. P. Coster, Angelo A. Tuccilo, Helmut Faugel, Philippe Jacquet, Wouter Tierens, Jean-Marie Noterdaeme, Laurent Colas, R. Bilato, Yuhe Feng, A. Kallenbach, M. Usoltceva, Guillermo Suárez, Jonathan Jacquot, Kristel Crombé, Yongsheng Wang, Dirk Van Eester, D. Aguiam, Riccardo Maggiora, O. Tudisco, R. Ochoukov, H. Fuenfgelder, V. Bobkov, Tudisco, O., Tuccilo, A. A., ASDEX Upgrade Team, Max Planck Institute for Plasma Physics, Max Planck Society, and EUROfusion MST1 Team

Subjects
Coupling, Chemistry, Nuclear engineering, Physics, QC1-999, Cyclotron, Plasma, 01 natural sciences, 7. Clean energy, 010305 fluids & plasmas, law.invention, ASDEX Upgrade, Impurity, law, 0103 physical sciences, Radio frequency, Atomic physics, 010306 general physics
Abstract

The recent scientific research on ASDEX Upgrade (AUG) has greatly advanced solutions to two issues of Radio Frequency (RF) heating in the Ion Cyclotron Range of Frequencies (ICRF): (a) the coupling of ICRF power to the plasma is significantly improved by density tailoring with local gas puffing; (b) the release of RF-specific impurities is significantly reduced by minimizing the RF near field with 3-strap antennas. This paper summarizes the applied methods and reviews the associated achievements. © 2017 The authors, published by EDP Sciences.

Published
2017

14. Radio frequency heating induced edge plasma convection: self-consistent simulations and experiments on ASDEX Upgrade

Author

Analiza M. Silva, J. Jacquot, D. P. Coster, Wouter Tierens, L. Colas, J.-M. Noterdaeme, H. Fuenfgelder, R. Ochoukov, Wei Zhang, Alena Křivská, D. Aguiam, V. Bobkov, ASDEX Upgrade Team, Max Planck Institute for Plasma Physics, Max Planck Society, and MST1 Team

Subjects
Convection, Nuclear and High Energy Physics, Materials science, Cyclotron, Plasma, Condensed Matter Physics, 7. Clean energy, 01 natural sciences, 010305 fluids & plasmas, law.invention, Computational physics, Dipole, ASDEX Upgrade, Physics::Plasma Physics, law, 0103 physical sciences, Dielectric heating, Antenna (radio), 010306 general physics, Convection cell
Abstract

Plasma heating with waves in the ion cyclotron range of frequency (ICRF) affects the edge plasma and the edge plasma affects the ICRF heating. In simulations, these nonlinear ICRF?edge plasma interactions have been self-consistently simulated by running the EMC3-EIRENE, RAPLICASOL and SSWICH codes in an iterative way on ASDEX Upgrade for the first time. In experiments, the edge plasma convection induced by powered 3-strap antennas is measured with the antenna embedded reflectometers for the first time. Both the simulation and experimental results indicate that the ICRF induced convective cells are most significant on the top and bottom of the antennas; the edge plasma convection induced by 3-strap antennas in optimized antenna feeding configuration (dipole phasing, power ratio between the center and outer straps ~1.5) is smallest among the studied cases. The simulation results also suggest that compared to the 2-strap antennas, the 3-strap antennas can significantly reduce the plasma convection associated with the radio-frequency sheaths, even with unfavorable power balance between the straps in dipole phasing.

Published
2017
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15. Characterization of edge turbulence in different states of divertor detachment using reflectometry in the ASDEX Upgrade tokamak

Author

Carlos A. Silva, A. Silva, V. Nikolaeva, José Vicente, E. Seliunin, P. Manz, Mst Team, J. M. Santos, M. E. Manso, D. Brida, L. Guimarais, D. Carralero, Ulrich Stroth, G. D. Conway, D. Aguiam, ASDEX Upgrade Team, Max Planck Institute for Plasma Physics, Max Planck Society, and MST1 Team

Subjects
Convection, Materials science, Tokamak, Turbulence, Divertor, Astrophysics::Cosmology and Extragalactic Astrophysics, Radius, Condensed Matter Physics, 01 natural sciences, 010305 fluids & plasmas, law.invention, Amplitude, Nuclear Energy and Engineering, ASDEX Upgrade, Physics::Plasma Physics, law, 0103 physical sciences, Atomic physics, 010306 general physics, Reflectometry
Abstract

Transport in the scrape-off layer (SOL) depends on the state of divertor detachment. L-mode discharges were analyzed where the state of divertor detachment is varied through a density ramp-up. By means of reflectometry measurements at the low (LFS) and the high field side (HFS), midplane density fluctuations are studied for the first time in ASDEX Upgrade simultaneously at both sides of the tokamak. Radial density fluctuation profiles () increase with radius in both the HFS and the LFS. It is found that in the SOL density fluctuations at the LFS have about a factor of two larger amplitude than at the HFS in agreement with ballooned transport. Density fluctuations at the LFS show a modest variation with increasing background density resulting mainly from a rise of low frequency components. Experimental results are in good agreement with an enhanced convection of filaments at the LFS at the beginning of outer divertor detachment leading to a flatter SOL density profile. In this phase of the discharge, density fluctuations measured at the HFS far-SOL display a strong increase, which may be associated with the presence of faster filaments originated at the LFS.

Published
2018
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16. Feasibility study of a control system based on PLC and EPICS for the ESTHER combustion gas injection

Author

D. Aguiam, Mario Lino da Silva, and Bernardo B. Carvalho

Subjects
Shock wave, Engineering, Spacecraft, business.industry, Control theory, Control system, Deflagration, Combustion chamber, business, Combustion, Shock tube, Simulation
Abstract

The ESTHER laboratory will simulate spacecraft atmosphere re-entry conditions by generating a shock wave through the deflagration of a hydrogen, oxygen and helium gas mixture. The gas injection sequence into the combustion chamber must be precisely and safely controlled in order to prescribe the initial pressure in the two-stage shock tube and to avoid accidental detonations in any part of the system. In this work, a prototype control system setup using a Siemens PLC in an EPICS and CSS software environment is presented. An example application was developed, where a simple control sequence implemented on the PLC was remotely monitored and controlled by an operator interface. This setup was able to meet the control system requirements and the prototype served as the starting point for the development of the complete ESTHER gas injection controller.

Published
2015
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17. Portable instrument for eddy currents Non-Destructive Testing based on heterodyning techniques

Author

D. Aguiam, Moisés Piedade, Pedro M. Ramos, and Luis S. Rosado

Subjects
Engineering, Signal generator, business.industry, Electrical engineering, Signal, law.invention, Portable computer, law, Nondestructive testing, Eddy-current testing, Operational transconductance amplifier, Eddy current, business, Voltage
Abstract

In this work an eddy current testing instrument employing heterodyning based measurements is presented. The instrument is composed of a portable computer and a dedicated electronic measurement circuitry to operate a specific type of probe. A DDS waveform generator and a transconductance amplifier are used to drive the probe with high amplitude currents and frequency up to 10 MHz. The probe output voltage is amplified up to 60 dB and down-converted to a lower intermediary frequency. The signal is converted into the digital domain and processed to compute the real and imaginary parts of the probe output voltage. The developed dedicated electronics were installed inside a rugged laptop computer to form a standalone instrument with post-processing and visualization capabilities. Electrical characterization and application results using the instrument and a particular eddy current probe are presented.

Published
2014
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18. Plasma edge modelling with ICRF coupling

Author

Y. Feng, T. Lunt, Jean-Marie Noterdaeme, D. P. Coster, R. Bilato, Wouter Tierens, Jonathan Jacquot, W. Zhang, D. Aguiam, Ph. Jacquet, E. Lerche, V. Bobkov, EUROfusion Mst Team, ASDEX Upgrade Team, Max Planck Institute for Plasma Physics, Max Planck Society, and EUROfusion MST1 Team

Subjects
Physics, Coupling, Convection, Range (particle radiation), QC1-999, Cyclotron, Plasma, Edge (geometry), 01 natural sciences, 010305 fluids & plasmas, law.invention, Ion, Core (optical fiber), Physics::Plasma Physics, law, 0103 physical sciences, Atomic physics, 010306 general physics
Abstract

The physics of Radio-Frequency (RF) wave heating in the Ion Cyclotron Range of Frequencies (ICRF) in the core plasmas of fusion devices are relatively well understood while those in the Scrape-Off Layer (SOL) remain still unresolved. This paper is dedicated to study the ICRF interactions with the plasma edge, mainly from the theoretical and numerical point of view, in particular with the 3D edge plasma fluid and neutral transport code EMC3-EIRENE and various wave codes. Here emphasis is given to the improvement of ICRF coupling with local gas puffing and to the ICRF induced density convection in the SOL.

Published
2017
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19. Making ICRF power compatible with a high-Z wall in ASDEX Upgrade

Author

Y.M. Wang, Qingxi Yang, A. Herrmann, D. Aguiam, Helmut Faugel, W. Zhang, Riccardo Maggiora, A. Tuccilo, L. Colas, O. Tudisco, H. Fünfgelder, V. Bobkov, R. Ochoukov, R. Bilato, S. Potzel, J.-M. Noterdaeme, J. Jacquot, Wouter Tierens, T. Pütterich, S. Brezinsek, Daniele Milanesio, A. Silva, A. Kallenbach, R. Neu, Tudisco, O., Tuccillo, A., ASDEX Upgrade Team, Max Planck Institute for Plasma Physics, Max Planck Society, and EUROfusion MST1 Team

Subjects
Tokamak, chemistry.chemical_element, Tungsten, antenna, ASDEX Upgrade, RF sheath, SSWICH, W sputtering, TOPICA, ICRF, 7. Clean energy, 01 natural sciences, 010305 fluids & plasmas, law.invention, ANTENNAS, Nuclear magnetic resonance, DESIGN, law, Sputtering, Electric field, 0103 physical sciences, Limiter, SHEATHS, 010306 general physics, Computer Science::Information Theory, Physics, Condensed Matter Physics, Computational physics, Power (physics), RETARDING-FIELD ANALYZER, Nuclear Energy and Engineering, chemistry, TOKAMAK, Antenna (radio)
Abstract

A comparison of the ASDEX Upgrade 3-strap ICRF antenna data with the linear electro-magnetic TOPICA calculations is presented. The comparison substantiates a reduction of the local electric field at the radially protruding plasma-facing elements of the antenna as a relevant approach for minimizing tungsten (W) sputtering in conditions when the slow wave is strongly evanescent. The measured reaction of the time-averaged RF current at the antenna limiters to the antenna feeding variations is less sensitive than predicted by the calculations. This is likely to have been caused by temporal and spatial fluctuations in the 3D plasma density distribution affected by local non-linear interactions. The 3-strap antenna with the W-coated limiters produces drastically less W sputtering compared to the W-coated 2-strap antennas. This is consistent with the non-linear asymptotic SSWICH-SW calculations for RF sheaths. © 2017 IOP Publishing Ltd.

Published
2016
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20. A double success story: The international cooperation to build the new ICRF antennas on ASDEX Upgrade and the results obtained

Author

D. Aguiam, G. Rocchi, A. Mancini, Helmut Faugel, O. D’Arcangelo, Daniele Milanesio, V. Bobkov, A. Silva, Y.M. Wang, EUROfusion Mst Team, I. Zammuto, H. Fünfgelder, J.-M. Noterdaeme, Qingxi Yang, A. A. Tuccillo, T. Vierle, J. Jacquot, Riccardo Maggiora, Yuqian Chen, O. Tudisco, R. Ochoukov, ASDEX Upgrade Team, Max Planck Institute for Plasma Physics, Max Planck Society, and EUROfusion MST1 Team

Subjects
Engineering, ICRF, business.industry, Nuclear engineering, Mechanical Engineering, Cyclotron, Schedule (project management), 7. Clean energy, 01 natural sciences, 010305 fluids & plasmas, law.invention, ASDEX Upgrade, ASDEX upgrade, Nuclear Energy and Engineering, law, Antenna, 0103 physical sciences, Civil and Structural Engineering, Materials Science (all), General Materials Science, Antenna (radio), 010306 general physics, business
Abstract

New ICRF (Ion Cyclotron Range of Frequency) antennas, targeted to reduce impurity generation in the all-metal ASDEX Upgrade were designed and fabricated at different sites in an international cooperation between IPP, ASIPP (Hefei, China) and ENEA (Frascati, Italy). Installation and test were done by a multinational team at IPP. The antenna further integrates a powerful reflectometer system, designed and built by ENEA and IST (Portugal). The project, with the cooperation of four institutes in four countries on two continents was successfully completed within budget and schedule boundaries. Test results, gathered during recent experiment campaign, reveal that the new antennas have achieved their goal: A significant reduction of ICRF heating induced W impurity generation at the antennas.

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21. Estimation of X-Mode Reflectometry First Fringe Frequency Using Neural Networks

Author

Jean-Marie Noterdaeme, António Rito Silva, L. Guimarais, O. Tudisco, Garrard Conway, P. J. Carvalho, L. Meneses, A. A. Tuccillo, Bruno Gonçalves, D. Aguiam, Jorge Manuel Santos, and ASDEX Upgrade Team, Max Planck Institute for Plasma Physics, Max Planck Society

Subjects
Physics, Nuclear and High Energy Physics, 020209 energy, 02 engineering and technology, Condensed Matter Physics, Interference (wave propagation), 01 natural sciences, Signal, Cutoff frequency, 010305 fluids & plasmas, 0103 physical sciences, 0202 electrical engineering, electronic engineering, information engineering, Cutoff, Antenna (radio), Reflectometry, Algorithm, Group delay and phase delay, Jitter
Abstract

One of the main challenges in X-mode reflectometry is the correct determination of the group delay measurement used for density profile reconstruction. The X-mode upper cutoff group delay measurement can be used to reconstruct the electron density profiles from the near zero density. However, due to the broad operational conditions of experimental fusion devices, the start of the upper cutoff region can occur at any probing frequency. The first fringe (FF) of the interference signal measured by reflectometry that corresponds to the start of the upper cutoff reflection is used together with the magnetic field profile to determine vacuum distance between the reflectometer antenna and the start of the plasma. An incorrect estimation of the FF probing frequency not only introduces a radial error but also a group delay error, affecting the shape of the resulting density profile. In this paper, we present the new developments in the automatic FF estimation required for the reliable reconstruction of density profiles, used in the multichannel X-mode density profile reflectometry diagnostic recently installed on ASDEX Upgrade. An improved algorithm to estimate and track the frequency of the FF along a discharge is introduced. Tests show that it is able to correctly determine the FF for most discharges. However, for a number of unanticipated cases, the algorithm provides jitter and imprecise results, introducing errors in the reconstructed density profiles. We also present a novel neural network (NN) approach for the first time for the estimation of the FF frequency. A comprehensive training set was carefully selected by experienced reflectometry diagnosticians and used to train the NN model using the open source software libraries TensorFlow and Keras. The resulting NN is able to provide more precise FF estimations than the previous algorithm. The reconstructed density profiles, using both algorithms, are presented and compared.

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22. Scrape-off layer transport and filament characteristics in high-density tokamak regimes.

Author

N. Vianello, D. Carralero, C.K. Tsui, V. Naulin, M. Agostini, I. Cziegler, B. Labit, C. Theiler, E. Wolfrum, D. Aguiam, S. Allan, M. Bernert, J. Boedo, S. Costea, H. De Oliveira, O. Fevrier, J. Galdon-Quiroga, G. Grenfell, A. Hakola, and C. Ionita

Subjects
FUSION reactors, FUSION reactor divertors, PLASMA sheaths, PLASMA currents, FIBERS, TOKAMAKS
Abstract

A detailed cross-device investigation on the role of filamentary dynamics in high-density regimes has been performed within the EUROfusion framework, comparing the ASDEX Upgrade (AUG) and TCV tokamaks. Both devices run density ramp experiments at different levels of plasma current, keeping the toroidal field or q95 constant in order to disentangle the role of the parallel connection length and the current. During the scan at a constant toroidal field, in both devices the scrape-off layer (SOL) profiles tend to develop a clear SOL density shoulder at a lower edge density whenever the current is reduced. Different current behaviour is substantially reconciled in terms of the edge density normalized to the Greenwald fraction. During the scan at constant q95 AUG exhibits similar behaviour, whereas in TCV no upstream profile modification signature has been observed at lower current levels. The latter behaviour has been ascribed to the lack of target density rollover. The relation between the upstream density profile modification and detachment condition has been investigated. For both devices the relation between blob size and the SOL density e-folding length is found independent of the plasma current, with the observation of a clear increase in blob size and the edge density normalized to a Greenwald fraction. ASDEX Upgrade has also explored filamentary behaviour in the H-mode. The experiments in AUG have focused on the role of neutrals, performing discharges with and without cryogenic pumps, highlighting how high neutral pressure, not only in the divertor but also at the midplane, is needed in order to develop an H-mode SOL profile shoulder in AUG. [ABSTRACT FROM AUTHOR]

Published
2020
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23. ICRF coupling in ASDEX upgrade magnetically perturbed 3D plasmas.

Author

G Suárez López, R Ochoukov, W Tierens, M Willensdorfer, H Zohm, D Aguiam, G Birkenmeier, V Bobkov, M Cavedon, M Dunne, H Faugel, R Fischer, H Fünfgelder, L Guimarãis, R McDermott, J-M Noterdaeme, E Seliunin, W Suttrop, team, the ASDEX Upgrade, and team, the EUROfusion-MST1

Subjects
RESISTANCE to change, PLASMA equilibrium, ANTENNAS (Electronics), COMPUTER simulation, CYCLOTRONS, POLOIDAL magnetic fields
Abstract

The RF properties of the four ion cyclotron range of frequencies (ICRF) antennas in the ASDEX Upgrade tokamak are characterized in H-mode magnetically perturbed 3D discharges. An n = 2 magnetic perturbation (MP) field is applied and rigidly rotated, which allows diagnosing the separatrix displacement and consequent coupling change. We find the antenna loading resistance to be coherently modified by the resulting non-axisymmetric plasma equilibria, thus becoming a function of the applied MP field poloidal mode spectra. We perform a detailed statistical analysis, which correlates the change in loading resistance to the fast wave R-cutoff layer movements. From it, a 1D scaling is derived that differs from previous studies evaluated in pure axisymmetric plasma conditions. This experimentally derived scaling is used to predict the average loading resistance change of the ITER ICRF antenna under applied MPs. ICRF coupling simulations using measured 1D density profiles are performed with the RAPLICASOL code, in order to investigate the predictive capabilities of numerical state of the art tools. We find that both 1D conventional scaling laws and 1D numerical simulations fail to capture the 3D physics, and can substantially overestimate the measured loading resistance change up to a factor of ∼3. [ABSTRACT FROM AUTHOR]

Published
2019
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24. Dependence on plasma shape and plasma fueling for small edge-localized mode regimes in TCV and ASDEX Upgrade.

Author

B. Labit, T. Eich, G.F. Harrer, E. Wolfrum, M. Bernert, M.G. Dunne, L. Frassinetti, P. Hennequin, R. Maurizio, A. Merle, H. Meyer, S. Saarelma, U. Sheikh, J. Adamek, M. Agostini, D. Aguiam, R. Akers, R. Albanese, C. Albert, and E. Alessi

Subjects
PLASMA density, GEOMETRIC shapes
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. [ABSTRACT FROM AUTHOR]

Published
2019
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25. Characterization of edge turbulence in different states of divertor detachment using reflectometry in the ASDEX Upgrade tokamak.

Author

V Nikolaeva, L Guimarais, P Manz, D Carralero, M E Manso, U Stroth, C Silva, G D Conway, E Seliunin, J Vicente, D Brida, D Aguiam, J Santos, A Silva, and Team, Asdex Upgrade Team And Mst1

Subjects
REFLECTOMETRY, TOKAMAKS, ELECTRON plasma, PLASMA boundary layers, ELECTRIC charge
Abstract

Transport in the scrape-off layer (SOL) depends on the state of divertor detachment. L-mode discharges were analyzed where the state of divertor detachment is varied through a density ramp-up. By means of reflectometry measurements at the low (LFS) and the high field side (HFS), midplane density fluctuations are studied for the first time in ASDEX Upgrade simultaneously at both sides of the tokamak. Radial density fluctuation profiles () increase with radius in both the HFS and the LFS. It is found that in the SOL density fluctuations at the LFS have about a factor of two larger amplitude than at the HFS in agreement with ballooned transport. Density fluctuations at the LFS show a modest variation with increasing background density resulting mainly from a rise of low frequency components. Experimental results are in good agreement with an enhanced convection of filaments at the LFS at the beginning of outer divertor detachment leading to a flatter SOL density profile. In this phase of the discharge, density fluctuations measured at the HFS far-SOL display a strong increase, which may be associated with the presence of faster filaments originated at the LFS. [ABSTRACT FROM AUTHOR]

Published
2018
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26. Effects of outer top gas injection on ICRF coupling in ASDEX Upgrade: towards modelling of ITER gas injection

Author

T. Lunt, G. Siegl, Jean-Marie Noterdaeme, R.A. Pitts, R. Bilato, J. Jacquot, D. Carralero, Wouter Tierens, V. Bobkov, L. Colas, D. Aguiam, Silvio Ceccuzzi, V. Rohde, D. P. Coster, Ph. Jacquet, H. Fuenfgelder, Analiza M. Silva, Wei Zhang, ASDEX Upgrade Team, Max Planck Institute for Plasma Physics, Max Planck Society, and Ceccuzzi, S.

Subjects
3D simulations, scrape-off layer, Cyclotron, gas puffing/fuelling, Edge (geometry), 01 natural sciences, ICRF coupling, 010305 fluids & plasmas, Ion, law.invention, ASDEX Upgrade, Physics::Plasma Physics, law, ITER, Quantum mechanics, 0103 physical sciences, crape-off layer, 010306 general physics, Physics, Coupling, Range (particle radiation), Plasma, Mechanics, Condensed Matter Physics, Nuclear Energy and Engineering, Antenna (radio)
Abstract

The influence of outer top gas injection on the scrape-off layer (SOL) density and ion cyclotron range of frequency (ICRF) coupling has been studied in ASDEX Upgrade (AUG) L-mode plasmas for the first time. The three-dimensional (3D) edge plasma fluid and neutral transport code EMC3-EIRENE is used to simulate the SOL plasma density, and the 3D wave code RAPLICASOL is used to compute the ICRF coupling resistance with the calculated density. Improvements have been made in the EMC3-EIRENE simulations by fitting transport parameters separately for each gas puffing case. It is found that the calculated local density profiles and coupling resistances are in good agreement with the experimental ones. The results indicate that the SOL density increase depends sensitively on the spreading of the injected outer top gas. If more gas enters into the main chamber through the paths near the top of vessel, the SOL density increase will be more toroidally uniform; if more gas chooses the paths closer to the mid-plane, then the SOL density increase will be more local and more significant. Among the various local gas puffing methods, the mid-plane gas valve close to the antenna is still the best option in terms of improving ICRF coupling. Differences between the outer top gas puffing in AUG and the outer top gas puffing in ITER are briefly summarized. Instructive suggestions for ITER and future plans for ITER gas injection simulations are discussed. © 2017 EUROfusion Max Planck Institute for Plasma Physics.

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27. Implementation of the new multichannel X-mode edge density profile reflectometer for the ICRF antenna on ASDEX Upgrade

Author

A. Silva, G. De Masi, P. F. Carvalho, J. M. Santos, L. Fattorini, Helmut Faugel, L. Guimarais, H. Fünfgelder, G. Rocchi, Ocleto D'Arcangelo, V. Bobkov, G. D. Conway, L. Meneses, R. Cavazzana, Ana Fernandes, P. J. Carvalho, D. Aguiam, A. A. Tuccillo, B. Gonçalves, J.-M. Noterdaeme, O. Tudisco, R. C. Pereira, ASDEX Upgrade Team, Max Planck Institute for Plasma Physics, Max Planck Society, Tudisco, O., Tuccillo, A. A., Rocchi, G., and D'Arcangelo, O.

Subjects
Physics, Electron density, business.industry, Cyclotron, Plasma, Edge (geometry), 01 natural sciences, 010305 fluids & plasmas, law.invention, Nuclear magnetic resonance, Optics, ASDEX Upgrade, law, Physics::Plasma Physics, 0103 physical sciences, Plasma diagnostics, Antenna (radio), 010306 general physics, business, Reflectometry, Instrumentation, SYSTEM
Abstract

A new multichannel frequency modulated continuous-wave reflectometry diagnostic has been successfully installed and commissioned on ASDEX Upgrade to measure the plasma edge electron density profile evolution in front of the Ion Cyclotron Range of Frequencies (ICRF) antenna. The design of the new three-strap ICRF antenna integrates ten pairs (sending and receiving) of microwave reflectometry antennas. The multichannel reflectometer can use three of these to measure the edge electron density profiles up to 2 × 1019 m-3, at different poloidal locations, allowing the direct study of the local plasma layers in front of the ICRF antenna. ICRF power coupling, operational effects, and poloidal variations of the plasma density profile can be consistently studied for the first time. In this work the diagnostic hardware architecture is described and the obtained density profile measurements were used to track outer radial plasma position and plasma shape. © 2016 EURATOM.

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28. Radio frequency heating induced edge plasma convection: self-consistent simulations and experiments on ASDEX Upgrade.

Author

W. Zhang, W. Tierens, J-M. Noterdaeme, V. Bobkov, D. Aguiam, D. Coster, H. Fuenfgelder, J. Jacquot, R. Ochoukov, A. Silva, L. Colas, A. Křivská, team, the ASDEX Upgrade, and team, the MST1

Subjects
RADIOFREQUENCY heating, PLASMA heating, CYCLOTRON resonance, PLASMA interactions, PLASMA sheaths
Abstract

Plasma heating with waves in the ion cyclotron range of frequency (ICRF) affects the edge plasma and the edge plasma affects the ICRF heating. In simulations, these nonlinear ICRF—edge plasma interactions have been self-consistently simulated by running the EMC3-EIRENE, RAPLICASOL and SSWICH codes in an iterative way on ASDEX Upgrade for the first time. In experiments, the edge plasma convection induced by powered 3-strap antennas is measured with the antenna embedded reflectometers for the first time. Both the simulation and experimental results indicate that the ICRF induced convective cells are most significant on the top and bottom of the antennas; the edge plasma convection induced by 3-strap antennas in optimized antenna feeding configuration (dipole phasing, power ratio between the center and outer straps ~1.5) is smallest among the studied cases. The simulation results also suggest that compared to the 2-strap antennas, the 3-strap antennas can significantly reduce the plasma convection associated with the radio-frequency sheaths, even with unfavorable power balance between the straps in dipole phasing. [ABSTRACT FROM AUTHOR]

Published
2017
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29. Overview of progress in European medium sized tokamaks towards an integrated plasma-edge/wall solution.

Author

H. Meyer, T. Eich, M. Beurskens, S. Coda, A. Hakola, P. Martin, J. Adamek, M. Agostini, and D. Aguiam

Subjects
TOKAMAKS, PLASMA core reactors, PLASMA boundary layers, PERTURBATION theory, FUSION reactor divertors
Abstract

Integrating the plasma core performance with an edge and scrape-off layer (SOL) that leads to tolerable heat and particle loads on the wall is a major challenge. The new European medium size tokamak task force (EU-MST) coordinates research on ASDEX Upgrade (AUG), MAST and TCV. This multi-machine approach within EU-MST, covering a wide parameter range, is instrumental to progress in the field, as ITER and DEMO core/pedestal and SOL parameters are not achievable simultaneously in present day devices. A two prong approach is adopted. On the one hand, scenarios with tolerable transient heat and particle loads, including active edge localised mode (ELM) control are developed. On the other hand, divertor solutions including advanced magnetic configurations are studied. Considerable progress has been made on both approaches, in particular in the fields of: ELM control with resonant magnetic perturbations (RMP), small ELM regimes, detachment onset and control, as well as filamentary scrape-off-layer transport. For example full ELM suppression has now been achieved on AUG at low collisionality with n  =  2 RMP maintaining good confinement . Advances have been made with respect to detachment onset and control. Studies in advanced divertor configurations (Snowflake, Super-X and X-point target divertor) shed new light on SOL physics. Cross field filamentary transport has been characterised in a wide parameter regime on AUG, MAST and TCV progressing the theoretical and experimental understanding crucial for predicting first wall loads in ITER and DEMO. Conditions in the SOL also play a crucial role for ELM stability and access to small ELM regimes. [ABSTRACT FROM AUTHOR]

Published
2017
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30. Effects of outer top gas injection on ICRF coupling in ASDEX Upgrade: towards modelling of ITER gas injection.

Author

W Zhang, V Bobkov, J-M Noterdaeme, W Tierens, R Bilato, D Carralero, D Coster, J Jacquot, P Jacquet, T Lunt, R A Pitts, V Rohde, G Siegl, H Fuenfgelder, D Aguiam, A Silva, L Colas, S Ceccuzzi, and Team, the ASDEX Upgrade

Subjects
GAS injection, CYCLOTRON resonance, PLASMA boundary layers, SIMULATION methods & models
Abstract

The influence of outer top gas injection on the scrape-off layer (SOL) density and ion cyclotron range of frequency (ICRF) coupling has been studied in ASDEX Upgrade (AUG) L-mode plasmas for the first time. The three-dimensional (3D) edge plasma fluid and neutral transport code EMC3-EIRENE is used to simulate the SOL plasma density, and the 3D wave code RAPLICASOL is used to compute the ICRF coupling resistance with the calculated density. Improvements have been made in the EMC3-EIRENE simulations by fitting transport parameters separately for each gas puffing case. It is found that the calculated local density profiles and coupling resistances are in good agreement with the experimental ones. The results indicate that the SOL density increase depends sensitively on the spreading of the injected outer top gas. If more gas enters into the main chamber through the paths near the top of vessel, the SOL density increase will be more toroidally uniform; if more gas chooses the paths closer to the mid-plane, then the SOL density increase will be more local and more significant. Among the various local gas puffing methods, the mid-plane gas valve close to the antenna is still the best option in terms of improving ICRF coupling. Differences between the outer top gas puffing in AUG and the outer top gas puffing in ITER are briefly summarized. Instructive suggestions for ITER and future plans for ITER gas injection simulations are discussed. [ABSTRACT FROM AUTHOR]

Published
2017
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31. Making ICRF power compatible with a high-Z wall in ASDEX Upgrade.

Author

V Bobkov, D Aguiam, R Bilato, S Brezinsek, L Colas, H Faugel, H Fünfgelder, A Herrmann, J Jacquot, A Kallenbach, D Milanesio, R Maggiora, R Neu, J-M Noterdaeme, R Ochoukov, S Potzel, T Pütterich, A Silva, W Tierens, and A Tuccilo

Subjects
ANTENNAS (Electronics), DIVERTERS (Electronics), ELECTROMAGNETISM, ELECTRIC fields, TUNGSTEN, SPUTTERING (Physics), PLASMA density
Abstract

A comparison of the ASDEX Upgrade 3-strap ICRF antenna data with the linear electro-magnetic TOPICA calculations is presented. The comparison substantiates a reduction of the local electric field at the radially protruding plasma-facing elements of the antenna as a relevant approach for minimizing tungsten (W) sputtering in conditions when the slow wave is strongly evanescent. The measured reaction of the time-averaged RF current at the antenna limiters to the antenna feeding variations is less sensitive than predicted by the calculations. This is likely to have been caused by temporal and spatial fluctuations in the 3D plasma density distribution affected by local non-linear interactions. The 3-strap antenna with the W-coated limiters produces drastically less W sputtering compared to the W-coated 2-strap antennas. This is consistent with the non-linear asymptotic SSWICH-SW calculations for RF sheaths. [ABSTRACT FROM AUTHOR]

Published
2017
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