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1. Experimental research on the TCV tokamak

Author

B.P. Duval, A. Abdolmaleki, M. Agostini, C.J. Ajay, S. Alberti, E. Alessi, G. Anastasiou, Y. Andrèbe, G.M. Apruzzese, F. Auriemma, J. Ayllon-Guerola, F. Bagnato, A. Baillod, F. Bairaktaris, L. Balbinot, A. Balestri, M. Baquero-Ruiz, C. Barcellona, M. Bernert, W. Bin, P. Blanchard, J. Boedo, T. Bolzonella, F. Bombarda, L. Boncagni, M. Bonotto, T.O.S.J. Bosman, D. Brida, D. Brunetti, J. Buchli, J. Buerman, P. Buratti, A. Burckhart, D. Busil, J. Caloud, Y. Camenen, A. Cardinali, S. Carli, D. Carnevale, F. Carpanese, M. Carpita, C. Castaldo, F. Causa, J. Cavalier, M. Cavedon, J.A. Cazabonne, J. Cerovsky, B. Chapman, M. Chernyshova, P. Chmielewski, A. Chomiczewska, G. Ciraolo, S. Coda, C. Colandrea, C. Contré, R. Coosemans, L. Cordaro, S. Costea, T. Craciunescu, K. Crombe, A. Dal Molin, O. D’Arcangelo, D. de Las Casas, J. Decker, J. Degrave, H. de Oliveira, G.L. Derks, L.E. di Grazia, C. Donner, M. Dreval, M.G. Dunne, G. Durr-Legoupil-Nicoud, B. Esposito, T. Ewalds, M. Faitsch, M. Farník, A. Fasoli, F. Felici, J. Ferreira, O. Février, O. Ficker, A. Frank, E. Fransson, L. Frassinetti, L. Fritz, I. Furno, D. Galassi, K. Gałązka, J. Galdon-Quiroga, S. Galeani, C. Galperti, S. Garavaglia, M. Garcia-Munoz, P. Gaudio, M. Gelfusa, J. Genoud, R. Gerrú Miguelanez, G. Ghillardi, M. Giacomin, L. Gil, A. Gillgren, C. Giroud, T. Golfinopoulos, T. Goodman, G. Gorini, S. Gorno, G. Grenfell, M. Griener, M. Gruca, T. Gyergyek, R. Hafner, M. Hamed, D. Hamm, W. Han, G. Harrer, J.R. Harrison, D. Hassabis, S. Henderson, P. Hennequin, J. Hidalgo-Salaverri, J-P. Hogge, M. Hoppe, J. Horacek, A. Huber, E. Huett, A. Iantchenko, P. Innocente, C. Ionita-Schrittwieser, I. Ivanova Stanik, M. Jablczynska, A. Jansen van Vuuren, A. Jardin, H. Järleblad, A.E. Järvinen, J. Kalis, R. Karimov, A.N. Karpushov, K. Kavukcuoglu, J. Kay, Y. Kazakov, J. Keeling, A. Kirjasuo, J.T.W. Koenders, P. Kohli, M. Komm, M. Kong, J. Kovacic, E. Kowalska-Strzeciwilk, O. Krutkin, O. Kudlacek, U. Kumar, R. Kwiatkowski, B. Labit, L. Laguardia, E. Laszynska, A. Lazaros, K. Lee, E. Lerche, B. Linehan, D. Liuzza, T. Lunt, E. Macusova, D. Mancini, P. Mantica, M. Maraschek, G. Marceca, S. Marchioni, A. Mariani, M. Marin, A. Marinoni, L. Martellucci, Y. Martin, P. Martin, L. Martinelli, F. Martinelli, J.R. Martin-Solis, S. Masillo, R. Masocco, V. Masson, A. Mathews, M. Mattei, D. Mazon, S. Mazzi, S.Y. Medvedev, C. Meineri, A. Mele, V. Menkovski, A. Merle, H. Meyer, K. Mikszuta-Michalik, I.G. Miron, P.A. Molina Cabrera, A. Moro, A. Murari, P. Muscente, D. Mykytchuk, F. Nabais, F. Napoli, R.D. Nem, M. Neunert, S.K. Nielsen, A. Nielsen, M. Nocente, S. Noury, S. Nowak, H. Nyström, N. Offeddu, S. Olasz, F. Oliva, D.S. Oliveira, F.P. Orsitto, N. Osborne, P. Oyola Dominguez, O. Pan, E. Panontin, A.D. Papadopoulos, P. Papagiannis, G. Papp, M. Passoni, F. Pastore, A. Pau, R.O. Pavlichenko, A.C. Pedersen, M. Pedrini, G. Pelka, E. Peluso, A. Perek, C. Perez Von Thun, F. Pesamosca, D. Pfau, V. Piergotti, L. Pigatto, C. Piron, L. Piron, A. Pironti, U. Plank, V. Plyusnin, Y.R.J. Poels, G.I. Pokol, J. Poley-Sanjuan, M. Poradzinski, L. Porte, C. Possieri, A. Poulsen, M.J. Pueschel, T. Pütterich, V. Quadri, M. Rabinski, R. Ragona, H. Raj, A. Redl, H. Reimerdes, C. Reux, D. Ricci, M. Riedmiller, S. Rienäcker, D. Rigamonti, N. Rispoli, J.F. Rivero-Rodriguez, C.F. Romero Madrid, J. Rueda Rueda, P.J. Ryan, M. Salewski, A. Salmi, M. Sassano, O. Sauter, N. Schoonheere, R.W. Schrittwieser, F. Sciortino, A. Selce, L. Senni, S. Sharapov, U.A. Sheikh, B. Sieglin, M. Silva, D. Silvagni, B. Simmendefeldt Schmidt, L. Simons, E.R. Solano, C. Sozzi, M. Spolaore, L. Spolladore, A. Stagni, P. Strand, G. Sun, W. Suttrop, J. Svoboda, B. Tal, T. Tala, P. Tamain, M. Tardocchi, A. Tema Biwole, A. Tenaglia, D. Terranova, D. Testa, C. Theiler, A. Thornton, A.S. Thrysoe, M. Tomes, E. Tonello, H. Torreblanca, B. Tracey, M. Tsimpoukelli, C. Tsironis, C.K. Tsui, M. Ugoletti, M. Vallar, M. van Berkel, S. van Mulders, M. van Rossem, C. Venturini, M. Veranda, T. Verdier, K. Verhaegh, L. Vermare, N. Vianello, E. Viezzer, F. Villone, B. Vincent, P. Vincenzi, I. Voitsekhovitch, L. Votta, N.M.T. Vu, Y. Wang, E. Wang, T. Wauters, M. Weiland, H. Weisen, N. Wendler, S. Wiesen, M. Wiesenberger, T. Wijkamp, C. Wüthrich, D. Yadykin, H. Yang, V. Yanovskiy, J. Zebrowski, P. Zestanakis, M. Zuin, and M. Zurita

Subjects
TCV, review, plasma, SPC, EPFL, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Tokamak à configuration variable (TCV), recently celebrating 30 years of near-continual operation, continues in its missions to advance outstanding key physics and operational scenario issues for ITER and the design of future power plants such as DEMO. The main machine heating systems and operational changes are first described. Then follow five sections: plasma scenarios. ITER Base-Line (IBL) discharges, triangularity studies together with X3 heating and N2 seeding. Edge localised mode suppression, with a high radiation region near the X-point is reported with N _2 injection with and without divertor baffles in a snowflake configuration. Negative triangularity (NT) discharges attained record, albeit transient, β _N ∼ 3 with lower turbulence, higher low-Z impurity transport, vertical stability and density limits and core transport better than the IBL. Positive triangularity L-Mode linear and saturated ohmic confinement confinement saturation, often-correlated with intrinsic toroidal rotation reversals, was probed for D, H and He working gases. H-mode confinement and pedestal studies were extended to low collisionality with electron cyclotron heating obtaining steady state electron iternal transport barrier with neutral beam heating (NBH), and NBH driven H-mode configurations with off-axis co-electron cyclotron current drive. Fast particle physics. The physics of disruptions, runaway electrons and fast ions (FIs) was developed using near-full current conversion at disruption with recombination thresholds characterised for impurity species (Ne, Ar, Kr). Different flushing gases (D2, H2) and pathways to trigger a benign disruption were explored. The 55 kV NBH II generated a rich Alfvénic spectrum modulating the FI fas ion loss detector signal. NT configurations showed less toroidal Alfvén excitation activity preferentially affecting higher FI pitch angles. Scrape-off layer and edge physics. gas puff imaging systems characterised turbulent plasma ejection for several advanced divertor configurations, including NT. Combined diagnostic array divertor state analysis in detachment conditions was compared to modelling revealing an importance for molecular processes. Divertor physics. Internal gas baffles diversified to include shorter/longer structures on the high and/or low field side to probe compressive efficiency. Divertor studies concentrated upon mitigating target power, facilitating detachment and increasing the radiated power fraction employing alternative divertor geometries, optimised X-point radiator regimes and long-legged configurations. Smaller-than-expected improvements with total flux expansion were better modelled when including parallel flows. Peak outer target heat flux reduction was achieved (>50%) for high flux-expansion geometries, maintaining core performance ( H _98 > 1). A reduction in target heat loads and facilitated detachment access at lower core densities is reported. Real-time control. TCV’s real-time control upgrades employed MIMO gas injector control of stable, robust, partial detachment and plasma β feedback control avoiding neoclassical tearing modes with plasma confinement changes. Machine-learning enhancements include trajectory tracking disruption proximity and avoidance as well as a first-of-its-kind reinforcement learning-based controller for the plasma equilibrium trained entirely on a free-boundary simulator. Finally, a short description of TCV’s immediate future plans will be given.

Published
2024
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2. Characterization of highly radiating nitrogen-seeded H-mode plasmas in unfavorable BT at ASDEX Upgrade

Author

L. Chen, E. Wolfrum, O. Pan, B. Kurzan, M. Bernert, D. Brida, M. Cavedon, R. Dux, R. Fischer, M. Griener, O. Grover, U. Plank, D. Stieglitz, A. Zito, and the ASDEX Upgrade Team

Subjects
divertor detachment, radiative senario, impurity seeding, unfavorable, SOLPS-ITER, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

The highly radiating nitrogen-seeded H-mode plasmas in unfavorable B _T has been characterized in the ASDEX Upgrade tokamak (AUG). Three levels of nitrogen puffing rates have been injected into a fully detached H-mode plasma, which is run in lower single null configuration with the ion $B\times\nabla B$ drift away from the X-point. A cold ( ${\sim}1-2$ eV) highly radiating ( ${\sim}13.0 \mathrm{MW\,\,\,m}^{-3}$ ) region forms close to the X-point immediately after nitrogen seeding, as evidenced by measurements of the divertor Thomson scattering (DTS) and the two-dimensional bolometry reconstructions. In addition, the radiator moves further upwards above the X-point along the separatrix at the high-field side (HFS) with increasing nitrogen puffing rates, as evidenced by the Absolute eXtended UltraViolet (AXUV) measurements. The formation of the highly radiating regime is closely correlated to the modifications of the divertor plasma conditions. Along the line of sight of the DTS measurement, the electron temperature reduces down to a few eV, which initials near the X-point and further extends to the HFS scrape-off layer (SOL) simultaneously with the upward movement of the radiator, however, the electron temperature sustains ( ${\sim}30-50 $ eV) at the low-field side (LFS) SOL with slightly decreased electron density. The highly radiating regime shows LFS/HFS divertor asymmetry, in contrast to that for H-mode plasmas in favorable B _T , suggesting that the drifts play an important role for the formation of the highly radiating X-point regime at AUG. The neutral particle flux increases significantly (factor of ${\sim}2$ ) in the private flux region, while it increases slightly ( $ \lt\!20\%$ ) in the main chamber, thus suggesting an enhanced sub-divertor neutral compression with the formation of the highly radiating regime. Furthermore, a degradation of the pedestal electron density was observed with an enhancement of the electron temperature further inside the pedestal, and complete divertor detachment was achieved by nitrogen seeding with sustained plasma confinement. Finally, particle sources and flow patterns of deuterium and nitrogen ions have been analyzed by SOLPS-ITER modelling, confirming that the $E \,\times\,B$ drift plays an important role for the formation of the highly radiating regime in unfavorable B _T at AUG.

Published
2024
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3. Overview of ASDEX upgrade results in view of ITER and DEMO

Author

H. Zohm, E. Alessi, C. Angioni, N. Arden, V. Artigues, M. Astrain, O. Asunta, M. Balden, V. Bandaru, A. Banon Navarro, M. Bauer, A. Bergmann, M. Bergmann, J. Bernardo, M. Bernert, A. Biancalani, R. Bielajew, R. Bilato, G. Birkenmeier, T. Blanken, V. Bobkov, A. Bock, L. 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, J. Buchanan, A. Buhler, A. Burckhart, Y. Camenen, B. Cannas, P. Cano Megías, D. Carlton, M. Carr, P. Carvalho, C. Castaldo, A. Castillo Castillo, A. Cathey, M. Cavedon, C. Cazzaniga, C. Challis, A. Chankin, A. Chomiczewska, 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, I. Cziegler, O. D’Arcangelo, A. Dal Molin, P. David, C. Day, M. de Baar, P. de Marné, R. Delogu, P. Denner, A. Di Siena, M. Dibon, J.J. Dominguez-Palacios Durán, D. Dunai, M. Dreval, M. Dunne, B.P. Duval, R. Dux, T. Eich, S. Elgeti, A. Encheva, B. Esposito, E. Fable, M. Faitsch, D. Fajardo Jimenez, U. Fantz, M. Farnik, H. Faugel, F. Felici, O. Ficker, 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, I. Girka, O. Girka, T. Gleiter, S. Glöggler, M. Gobbin, J.C. Gonzalez, J. Gonzalez Martin, T. Goodman, G. Gorini, T. Görler, D. Gradic, G. Granucci, A. Gräter, G. Grenfell, H. Greuner, M. Griener, M. Groth, O. Grover, A. Gude, L. Guimarais, S. Günter, D. Hachmeister, A.H. Hakola, C. Ham, T. Happel, N. den Harder, G. Harrer, J. Harrison, V. Hauer, T. Hayward-Schneider, B. Heinemann, P. Heinrich, T. Hellsten, S. Henderson, P. Hennequin, M. Herschel, S. Heuraux, A. Herrmann, E. Heyn, F. Hitzler, J. Hobirk, K. Höfler, S. Hörmann, J.H. Holm, M. Hölzl, C. Hopf, L. Horvath, T. Höschen, A. Houben, A. Hubbard, A. Huber, K. Hunger, V. Igochine, M. Iliasova, J. Illerhaus, K. Insulander Björk, C. Ionita-Schrittwieser, I. Ivanova-Stanik, S. Jachmich, W. Jacob, N. Jaksic, A. Jansen van Vuuren, F. Jaulmes, F. Jenko, T. Jensen, E. Joffrin, A. Kallenbach, J. Kalis, A. Kappatou, J. Karhunen, C.-P. Käsemann, S. Kasilov, Y. Kazakov, A. Kendl, W. Kernbichler, E. Khilkevitch, M. Kircher, A. Kirk, S. Kjer Hansen, V. Klevarova, F. Klossek, G. Kocsis, M. Koleva, M. Komm, M. Kong, A. Krämer-Flecken, M. Krause, I. Krebs, A. Kreuzeder, K. Krieger, O. Kudlacek, D. Kulla, T. Kurki-Suonio, B. Kurzan, B. Labit, K. Lackner, F. Laggner, A. Lahtinen, P. Lainer, P.T. Lang, P. Lauber, M. Lehnen, L. Leppin, E. Lerche, N. Leuthold, L. Li, J. Likonen, O. Linder, H. Lindl, B. Lipschultz, Y. Liu, 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, V. Maquet, A. Mancini, A. Manhard, P. Mantica, M. Mantsinen, P. Manz, M. Maraschek, C. Marchetto, M. Markl, L. Marrelli, P. Martin, F. Matos, M. Mayer, P.J. McCarthy, R. McDermott, G. Meng, R. Merkel, A. Merle, H. Meyer, M. Michelini, D. Milanesio, V. Mitterauer, P. Molina Cabrera, M. Muraca, F. Nabais, V. Naulin, R. Nazikian, R.D. Nem, R. Neu, A.H. Nielsen, S.K. Nielsen, T. Nishizawa, M. Nocente, I. Novikau, S. Nowak, R. Ochoukov, J. Olsen, P. Oyola, O. Pan, G. Papp, A. Pau, G. Pautasso, C. Paz-Soldan, M. Peglau, E. Peluso, P. Petersson, C. Piron, U. Plank, B. Plaum, B. Plöckl, V. Plyusnin, G. Pokol, E. Poli, A. Popa, L. Porte, J. Puchmayr, T. Pütterich, L. Radovanovic, M. Ramisch, J. Rasmussen, G. Ratta, S. Ratynskaia, G. Raupp, A. Redl, D. Réfy, M. Reich, F. Reimold, D. Reiser, M. Reisner, D. Reiter, B. Rettino, T. Ribeiro, D. Ricci, R. Riedl, J. Riesch, J.F. Rivero Rodriguez, G. Rocchi, P. Rodriguez-Fernandez, V. Rohde, G. Ronchi, 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, A. Schlüter, J. Scholte, K. Schmid, O. Schmitz, P.A. Schneider, R. Schrittwieser, M. Schubert, C. Schuster, N. Schwarz, T. Schwarz-Selinger, J. Schweinzer, F. Sciortino, O. Seibold-Benjak, 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, A. Snicker, E. Solano, C. Sommariva, C. Sozzi, M. Spacek, G. Spizzo, M. Spolaore, A. Stegmeir, M. Stejner, D. Stieglitz, J. Stober, U. Stroth, E. Strumberger, G. Suarez Lopez, W. Suttrop, T. Szepesi, B. Tál, T. Tala, W. Tang, G. Tardini, M. Tardocchi, D. Terranova, M. Teschke, E. Thorén, W. Tierens, D. Told, W. Treutterer, G. Trevisan, M. Tripský, P. Ulbl, G. Urbanczyk, M. Usoltseva, M. Valisa, M. Valovic, S. van Mulders, M. van Zeeland, F. Vannini, B. Vanovac, P. Varela, S. Varoutis, T. Verdier, G. Verdoolaege, N. Vianello, J. Vicente, T. Vierle, E. Viezzer, I. Voitsekhovitch, U. von Toussaint, D. Wagner, X. Wang, M. Weiland, D. Wendler, A.E. White, M. Willensdorfer, B. Wiringer, M. Wischmeier, R. Wolf, E. Wolfrum, Q. Yang, C. Yoo, Q. Yu, R. Zagórski, I. Zammuto, T. Zehetbauer, W. Zhang, W. Zholobenko, A. Zibrov, M. Zilker, C.F.B. Zimmermann, A. Zito, S. Zoletnik, the EUROfusion Tokamak Exploitation Team, and the ASDEX Upgrade Team

Subjects
tokamak, MHD stability, transport modelling, radiative exhaust, disruption physics, ELM free scenarios, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Experiments on ASDEX Upgrade (AUG) in 2021 and 2022 have addressed a number of critical issues for ITER and EU DEMO. A major objective of the AUG programme is to shed light on the underlying physics of confinement, stability, and plasma exhaust in order to allow reliable extrapolation of results obtained on present day machines to these reactor-grade devices. Concerning pedestal physics, the mitigation of edge localised modes (ELMs) using resonant magnetic perturbations (RMPs) was found to be consistent with a reduction of the linear peeling-ballooning stability threshold due to the helical deformation of the plasma. Conversely, ELM suppression by RMPs is ascribed to an increased pedestal transport that keeps the plasma away from this boundary. Candidates for this increased transport are locally enhanced turbulence and a locked magnetic island in the pedestal. The enhanced D-alpha (EDA) and quasi-continuous exhaust (QCE) regimes have been established as promising ELM-free scenarios. Here, the pressure gradient at the foot of the H-mode pedestal is reduced by a quasi-coherent mode, consistent with violation of the high-n ballooning mode stability limit there. This is suggestive that the EDA and QCE regimes have a common underlying physics origin. In the area of transport physics, full radius models for both L- and H-modes have been developed. These models predict energy confinement in AUG better than the commonly used global scaling laws, representing a large step towards the goal of predictive capability. A new momentum transport analysis framework has been developed that provides access to the intrinsic torque in the plasma core. In the field of exhaust, the X-Point Radiator (XPR), a cold and dense plasma region on closed flux surfaces close to the X-point, was described by an analytical model that provides an understanding of its formation as well as its stability, i.e., the conditions under which it transitions into a deleterious MARFE with the potential to result in a disruptive termination. With the XPR close to the divertor target, a new detached divertor concept, the compact radiative divertor, was developed. Here, the exhaust power is radiated before reaching the target, allowing close proximity of the X-point to the target. No limitations by the shallow field line angle due to the large flux expansion were observed, and sufficient compression of neutral density was demonstrated. With respect to the pumping of non-recycling impurities, the divertor enrichment was found to mainly depend on the ionisation energy of the impurity under consideration. In the area of MHD physics, analysis of the hot plasma core motion in sawtooth crashes showed good agreement with nonlinear 2-fluid simulations. This indicates that the fast reconnection observed in these events is adequately described including the pressure gradient and the electron inertia in the parallel Ohm’s law. Concerning disruption physics, a shattered pellet injection system was installed in collaboration with the ITER International Organisation. Thanks to the ability to vary the shard size distribution independently of the injection velocity, as well as its impurity admixture, it was possible to tailor the current quench rate, which is an important requirement for future large devices such as ITER. Progress was also made modelling the force reduction of VDEs induced by massive gas injection on AUG. The H-mode density limit was characterised in terms of safe operational space with a newly developed active feedback control method that allowed the stability boundary to be probed several times within a single discharge without inducing a disruptive termination. Regarding integrated operation scenarios, the role of density peaking in the confinement of the ITER baseline scenario (high plasma current) was clarified. The usual energy confinement scaling ITER98( p,y ) does not capture this effect, but the more recent H20 scaling does, highlighting again the importance of developing adequate physics based models. Advanced tokamak scenarios, aiming at large non-inductive current fraction due to non-standard profiles of the safety factor in combination with high normalised plasma pressure were studied with a focus on their access conditions. A method to guide the approach of the targeted safety factor profiles was developed, and the conditions for achieving good confinement were clarified. Based on this, two types of advanced scenarios (‘hybrid’ and ‘elevated’ q -profile) were established on AUG and characterised concerning their plasma performance.

Published
2024
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4. Overview of the EUROfusion Tokamak Exploitation programme in support of ITER and DEMO

Author

E. Joffrin, M. Wischmeier, M. Baruzzo, A. Hakola, A. Kappatou, D. Keeling, B. Labit, E. Tsitrone, N. Vianello, the ASDEX Upgrade Team, JET Contributors, the MAST-U Team, the TCV Team, the WEST Team, the EUROfusion Tokamak Exploitation Team:, D. Abate, J. Adamek, M. Agostini, C. Albert, F.C.P. Albert Devasagayam, S. Aleiferis, E. Alessi, J. Alhage, S. Allan, J. Allcock, M. Alonzo, G. Anastasiou, E. Andersson Sunden, C. Angioni, Y. Anquetin, L. Appel, G.M. Apruzzese, M. Ariola, C. Arnas, J.F. Artaud, W. Arter, O. Asztalos, L. Aucone, M.H. Aumeunier, F. Auriemma, J. Ayllon, E. Aymerich, A. Baciero, F. Bagnato, L. Bähner, F. Bairaktaris, P. Balázs, L. Balbinot, I. Balboa, M. Balden, A. Balestri, M. Baquero Ruiz, T. Barberis, C. Barcellona, O. Bardsley, S. Benkadda, T. Bensadon, E. Bernard, M. Bernert, H. Betar, R. Bianchetti Morales, J. Bielecki, R. Bilato, P. Bilkova, W. Bin, G. Birkenmeier, R. Bisson, P. Blanchard, A. Bleasdale, V. Bobkov, A. Boboc, A. Bock, K. Bogar, P. Bohm, T. Bolzonella, F. Bombarda, N. Bonanomi, L. Boncagni, D. Bonfiglio, R. Bonifetto, M. Bonotto, D. Borodin, I. Borodkina, T.O.S.J. Bosman, C. Bourdelle, C. Bowman, S. Brezinsek, D. Brida, F. Brochard, R. Brunet, D. Brunetti, V. Bruno, R. Buchholz, J. Buermans, H. Bufferand, P. Buratti, A. Burckhart, J. Cai, R. Calado, J. Caloud, S. Cancelli, F. Cani, B. Cannas, M. Cappelli, S. Carcangiu, A. Cardinali, S. Carli, D. Carnevale, M. Carole, M. Carpita, D. Carralero, F. Caruggi, I.S. Carvalho, I. Casiraghi, A. Casolari, F.J. Casson, C. Castaldo, A. Cathey, F. Causa, J. Cavalier, M. Cavedon, J. Cazabonne, M. Cecconello, L. Ceelen, A. Celora, J. Cerovsky, C.D. Challis, R. Chandra, A. Chankin, B. Chapman, H. Chen, M. Chernyshova, A.G. Chiariello, P. Chmielewski, A. Chomiczewska, C. Cianfarani, G. Ciraolo, J. Citrin, F. Clairet, S. Coda, R. Coelho, J.W. Coenen, I.H. Coffey, C. Colandrea, L. Colas, S. Conroy, C. Contre, N.J. Conway, L. Cordaro, Y. Corre, D. Costa, S. Costea, D. Coster, X. Courtois, C. Cowley, T. Craciunescu, G. Croci, A.M. Croitoru, K. Crombe, D.J. Cruz Zabala, G. Cseh, T. Czarski, A. Da Ros, A. Dal Molin, M. Dalla Rosa, Y. Damizia, O. D’Arcangelo, P. David, M. De Angeli, E. De la Cal, E. De La Luna, G. De Tommasi, J. Decker, R. Dejarnac, D. Del Sarto, G. Derks, C. Desgranges, P. Devynck, S. Di Genova, L.E. di Grazia, A. Di Siena, M. Dicorato, M. Diez, M. Dimitrova, T. Dittmar, L. Dittrich, J.J. Domínguez Palacios Durán, P. Donnel, D. Douai, S. Dowson, S. Doyle, M. Dreval, P. Drews, L. Dubus, R. Dumont, D. Dunai, M. Dunne, A. Durif, F. Durodie, G. Durr Legoupil Nicoud, B. Duval, R. Dux, T. Eich, A. Ekedahl, S. Elmore, G. Ericsson, J. Eriksson, B. Eriksson, F. Eriksson, S. Ertmer, A. Escarguel, B. Esposito, T. Estrada, E. Fable, M. Faitsch, N. Fakhrayi Mofrad, A. Fanni, T. Farley, M. Farník, N. Fedorczak, F. Felici, X. Feng, J. Ferreira, D. Ferreira, N. Ferron, O. Fevrier, O. Ficker, A.R. Field, A. Figueiredo, N. Fil, D. Fiorucci, M. Firdaouss, R. Fischer, M. Fitzgerald, M. Flebbe, M. Fontana, J. Fontdecaba Climent, A. Frank, E. Fransson, L. Frassinetti, D. Frigione, S. Futatani, R. Futtersack, S. Gabriellini, D. Gadariya, D. Galassi, K. Galazka, J. Galdon, S. Galeani, D. Gallart, A. Gallo, C. Galperti, M. Gambrioli, S. Garavaglia, J. Garcia, M. Garcia Munoz, J. Gardarein, L. Garzotti, J. Gaspar, R. Gatto, P. Gaudio, M. Gelfusa, J. Gerardin, S.N. Gerasimov, R. Gerru Miguelanez, G. Gervasini, Z. Ghani, F.M. Ghezzi, G. Ghillardi, L. Giannone, S. Gibson, L. Gil, A. Gillgren, E. Giovannozzi, C. Giroud, G. Giruzzi, T. Gleiter, M. Gobbin, V. Goloborodko, A. González Ganzábal, T. Goodman, V. Gopakumar, G. Gorini, T. Görler, S. Gorno, G. Granucci, D. Greenhouse, G. Grenfell, M. Griener, W. Gromelski, M. Groth, O. Grover, M. Gruca, A. Gude, C. Guillemaut, R. Guirlet, J. Gunn, T. Gyergyek, L. Hagg, J. Hall, C.J. Ham, M. Hamed, T. Happel, G. Harrer, J. Harrison, D. Harting, N.C. Hawkes, P. Heinrich, S. Henderson, P. Hennequin, R. Henriques, S. Heuraux, J. Hidalgo Salaverri, J. Hillairet, J.C. Hillesheim, A. Hjalmarsson, A. Ho, J. Hobirk, E. Hodille, M. Hölzl, M. Hoppe, J. Horacek, N. Horsten, L. Horvath, M. Houry, K. Hromasova, J. Huang, Z. Huang, A. Huber, E. Huett, P. Huynh, A. Iantchenko, M. Imrisek, P. Innocente, C. Ionita Schrittwieser, H. Isliker, P. Ivanova, I. Ivanova Stanik, M. Jablczynska, S. Jachmich, A.S. Jacobsen, P. Jacquet, A. Jansen van Vuuren, A. Jardin, H. Järleblad, A. Järvinen, F. Jaulmes, T. Jensen, I. Jepu, S. Jessica, T. Johnson, A. Juven, J. Kalis, J. Karhunen, R. Karimov, A.N. Karpushov, S. Kasilov, Y. Kazakov, P.V. Kazantzidis, W. Kernbichler, HT. Kim, D.B. King, V.G. Kiptily, A. Kirjasuo, K.K. Kirov, A. Kirschner, A. Kit, T. Kiviniemi, F. Kjær, E. Klinkby, A. Knieps, U. Knoche, M. Kochan, F. Köchl, G. Kocsis, J.T.W. Koenders, L. Kogan, Y. Kolesnichenko, Y. Kominis, M. Komm, M. Kong, B. Kool, S.B. Korsholm, D. Kos, M. Koubiti, J. Kovacic, Y. Kovtun, E. Kowalska Strzeciwilk, K. Koziol, M. Kozulia, A. Krämer Flecken, A. Kreter, K. Krieger, U. Kruezi, O. Krutkin, O. Kudlacek, U. Kumar, H. Kumpulainen, M.H. Kushoro, R. Kwiatkowski, M. La Matina, M. Lacquaniti, L. Laguardia, P. Lainer, P. Lang, M. Larsen, E. Laszynska, K.D. Lawson, A. Lazaros, E. Lazzaro, M.Y.K. Lee, S. Leerink, M. Lehnen, M. Lennholm, E. Lerche, Y. Liang, A. Lier, J. Likonen, O. Linder, B. Lipschultz, A. Listopad, X. Litaudon, E. Litherland Smith, D. Liuzza, T. Loarer, P.J. Lomas, J. Lombardo, N. Lonigro, R. Lorenzini, C. Lowry, T. Luda di Cortemiglia, A. Ludvig Osipov, T. Lunt, V. Lutsenko, E. Macusova, R. Mäenpää, P. Maget, C.F. Maggi, J. Mailloux, S. Makarov, K. Malinowski, P. Manas, A. Mancini, D. Mancini, P. Mantica, M. Mantsinen, J. Manyer, M. Maraschek, G. Marceca, G. Marcer, C. Marchetto, S. Marchioni, A. Mariani, M. Marin, M. Markl, T. Markovic, D. Marocco, S. Marsden, L. Martellucci, P. Martin, C. Martin, F. Martinelli, L. Martinelli, J.R. Martin Solis, R. Martone, M. Maslov, R. Masocco, M. Mattei, G.F. Matthews, D. Matveev, E. Matveeva, M.L. Mayoral, D. Mazon, S. Mazzi, C. Mazzotta, G. McArdle, R. McDermott, K. McKay, A.G. Meigs, C. Meineri, A. Mele, V. Menkovski, S. Menmuir, A. Merle, H. Meyer, K. Mikszuta Michalik, D. Milanesio, F. Militello, A. Milocco, I.G. Miron, J. Mitchell, R. Mitteau, V. Mitterauer, J. Mlynar, V. Moiseenko, P. Molna, F. Mombelli, C. Monti, A. Montisci, J. Morales, P. Moreau, J.M. Moret, A. Moro, D. Moulton, P. Mulholland, M. Muraglia, A. Murari, A. Muraro, P. Muscente, D. Mykytchuk, F. Nabais, Y. Nakeva, F. Napoli, E. Nardon, M.F. Nave, R.D. Nem, A. Nielsen, S.K. Nielsen, M. Nocente, R. Nouailletas, S. Nowak, H. Nyström, R. Ochoukov, N. Offeddu, S. Olasz, C. Olde, F. Oliva, D. Oliveira, H.J.C. Oliver, P. Ollus, J. Ongena, F.P. Orsitto, N. Osborne, R. Otin, P. Oyola Dominguez, D.I. Palade, S. Palomba, O. Pan, N. Panadero, E. Panontin, A. Papadopoulos, P. Papagiannis, G. Papp, V.V. Parail, C. Pardanaud, J. Parisi, A. Parrott, K. Paschalidis, M. Passoni, F. Pastore, A. Patel, B. Patel, A. Pau, G. Pautasso, R. Pavlichenko, E. Pawelec, B. Pegourie, G. Pelka, E. Peluso, A. Perek, E. Perelli Cippo, C. Perez Von Thun, P. Petersson, G. Petravich, Y. Peysson, V. Piergotti, L. Pigatto, C. Piron, L. Piron, A. Pironti, F. Pisano, U. Plank, B. Ploeckl, V. Plyusnin, A. Podolnik, Y. Poels, G. Pokol, J. Poley, G. Por, M. Poradzinski, F. Porcelli, L. Porte, C. Possieri, A. Poulsen, I. Predebon, G. Pucella, M. Pueschel, P. Puglia, O. Putignano, T. Pütterich, V. Quadri, A. Quercia, M. Rabinski, L. Radovanovic, R. Ragona, H. Raj, M. Rasinski, J. Rasmussen, G. Ratta, S. Ratynskaia, R. Rayaprolu, M. Rebai, A. Redl, D. Rees, D. Refy, M. Reich, H. Reimerdes, B.C.G. Reman, O. Renders, C. Reux, D. Ricci, M. Richou, S. Rienacker, D. Rigamonti, F. Rigollet, F.G. Rimini, D. Ripamonti, N. Rispoli, N. Rivals, J.F. Rivero Rodriguez, C. Roach, G. Rocchi, S. Rode, P. Rodrigues, J. Romazanov, C.F. Romero Madrid, J. Rosato, R. Rossi, G. Rubino, J. Rueda Rueda, J. Ruiz Ruiz, P. Ryan, D. Ryan, S. Saarelma, R. Sabot, M. Salewski, A. Salmi, L. Sanchis, A. Sand, J. Santos, K. Särkimäki, M. Sassano, O. Sauter, G. Schettini, S. Schmuck, P. Schneider, N. Schoonheere, R. Schramm, R. Schrittwieser, C. Schuster, N. Schwarz, F. Sciortino, M. Scotto D’Abusco, S. Scully, A. Selce, L. Senni, M. Senstius, G. Sergienko, S.E. Sharapov, R. Sharma, A. Shaw, U. Sheikh, G. Sias, B. Sieglin, S.A. Silburn, C. Silva, A. Silva, D. Silvagni, B. Simmendefeldt Schmidt, L. Simons, J. Simpson, L. Singh, S. Sipilä, Y. Siusko, S. Smith, A. Snicker, E.R. Solano, V. Solokha, M. Sos, C. Sozzi, F. Spineanu, G. Spizzo, M. Spolaore, L. Spolladore, C. Srinivasan, A. Stagni, Z. Stancar, G. Stankunas, J. Stober, P. Strand, C.I. Stuart, F. Subba, G.Y. Sun, H.J. Sun, W. Suttrop, J. Svoboda, T. Szepesi, G. Szepesi, B. Tal, T. Tala, P. Tamain, G. Tardini, M. Tardocchi, D. Taylor, G. Telesca, A. Tenaglia, A. Terra, D. Terranova, D. Testa, C. Theiler, E. Tholerus, B. Thomas, E. Thoren, A. Thornton, A. Thrysoe, Q. TICHIT, W. Tierens, A. Titarenko, P. Tolias, E. Tomasina, M. Tomes, E. Tonello, A. Tookey, M. Toscano Jiménez, C. Tsironis, C. Tsui, A. Tykhyy, M. Ugoletti, M. Usoltseva, D.F. Valcarcel, A. Valentini, M. Valisa, M. Vallar, M. Valovic, SI. Valvis, M. van Berkel, D. Van Eester, S. Van Mulders, M. van Rossem, R. Vann, B. Vanovac, J. Varela Rodriguez, J. Varje, S. Vartanian, M. Vecsei, L. Velarde Gallardo, M. Veranda, T. Verdier, G. Verdoolaege, K. Verhaegh, L. Vermare, G. Verona Rinati, J. Vicente, E. Viezzer, L. Vignitchouk, F. Villone, B. Vincent, P. Vincenzi, M.O. Vlad, G. Vogel, I. Voitsekhovitch, I. Voldiner, P. Vondracek, N.M.T. VU, T. Vuoriheimo, C. Wade, E. Wang, T. Wauters, M. Weiland, H. Weisen, N. Wendler, D. Weston, A. Widdowson, S. Wiesen, M. Wiesenberger, T. Wijkamp, M. Willensdorfer, T. Wilson, A. Wojenski, C. Wuethrich, I. Wyss, L. Xiang, S. Xu, D. Yadykin, Y. Yakovenko, H. Yang, V. Yanovskiy, R. Yi, B. Zaar, G. Zadvitskiy, L. Zakharov, P. Zanca, D. Zarzoso, Y. Zayachuk, J. Zebrowski, M. Zerbini, P. Zestanakis, C. F. B. Zimmermann, M. Zlobinski, A. Zohar, V.K. Zotta, X. Zou, M. Zuin, M. Zurita, and I. Zychor

Subjects
JET, ASDEX Upgrade, MAST-U, TCV, WEST, Tokamak Exploitation Task Force, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Within the 9th European Framework programme, since 2021 EUROfusion is operating five tokamaks under the auspices of a single Task Force called ‘Tokamak Exploitation’. The goal is to benefit from the complementary capabilities of each machine in a coordinated way and help in developing a scientific output scalable to future largre machines. The programme of this Task Force ensures that ASDEX Upgrade, MAST-U, TCV, WEST and JET (since 2022) work together to achieve the objectives of Missions 1 and 2 of the EUROfusion Roadmap: i) demonstrate plasma scenarios that increase the success margin of ITER and satisfy the requirements of DEMO and, ii) demonstrate an integrated approach that can handle the large power leaving ITER and DEMO plasmas. The Tokamak Exploitation task force has therefore organized experiments on these two missions with the goal to strengthen the physics and operational basis for the ITER baseline scenario and for exploiting the recent plasma exhaust enhancements in all four devices (PEX: Plasma EXhaust) for exploring the solution for handling heat and particle exhaust in ITER and develop the conceptual solutions for DEMO. The ITER Baseline scenario has been developed in a similar way in ASDEX Upgrade, TCV and JET. Key risks for ITER such as disruptions and run-aways have been also investigated in TCV, ASDEX Upgrade and JET. Experiments have explored successfully different divertor configurations (standard, super-X, snowflakes) in MAST-U and TCV and studied tungsten melting in WEST and ASDEX Upgrade. The input from the smaller devices to JET has also been proven successful to set-up novel control schemes on disruption avoidance and detachment.

Published
2024
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5. Overview of T and D–T results in JET with ITER-like wall

Author

C.F. Maggi, D. Abate, N. Abid, P. Abreu, O. Adabonyan, M. Afzal, I. Ahmad, M. Akhtar, R. Albanese, S. Aleiferis, E. Alessi, P. Aleynikov, J. Alguacil, J. Alhage, M. Ali, H. Allen, M. Allinson, M. Alonzo, E. Alves, R. Ambrosino, E. Andersson Sundén, P. Andrew, M. Angelone, C. Angioni, I. Antoniou, L. Appel, C. Appelbee, C. Aramunde, M. Ariola, G. Arnoux, G. Artaserse, J.-F. Artaud, W. Arter, V. Artigues, F.J. Artola, A. Ash, O. Asztalos, D. Auld, F. Auriemma, Y. Austin, L. Avotina, J. Ayllón, E. Aymerich, A. Baciero, L. Bähner, F. Bairaktaris, I. Balboa, M. Balden, N. Balshaw, V.K. Bandaru, J. Banks, A. Banon Navarro, C. Barcellona, O. Bardsley, M. Barnes, R. Barnsley, M. Baruzzo, M. Bassan, A. Batista, P. Batistoni, L. Baumane, B. Bauvir, L. Baylor, C. Bearcroft, P. Beaumont, D. Beckett, A. Begolli, M. Beidler, N. Bekris, M. Beldishevski, E. Belli, F. Belli, S. Benkadda, J. Bentley, E. Bernard, J. Bernardo, M. Bernert, M. Berry, L. Bertalot, H. Betar, M. Beurskens, P.G. Bhat, S. Bickerton, J. Bielecki, T. Biewer, R. Bilato, P. Bílková, G. Birkenmeier, R. Bisson, J.P.S. Bizarro, P. Blatchford, A. Bleasdale, V. Bobkov, A. Boboc, A. Bock, G. Bodnar, P. Bohm, L. Bonalumi, N. Bonanomi, D. Bonfiglio, X. Bonnin, P. Bonofiglo, J. Booth, D. Borba, D. Borodin, I. Borodkina, T.O.S.J. Bosman, C. Bourdelle, M. Bowden, I. Božičević Mihalić, S.C. Bradnam, B. Breizman, S. Brezinsek, D. Brida, M. Brix, P. Brown, D. Brunetti, M. Buckley, J. Buermans, H. Bufferand, P. Buratti, A. Burckhart, A. Burgess, A. Buscarino, A. Busse, D. Butcher, G. Calabrò, L. Calacci, R. Calado, R. Canavan, B. Cannas, M. Cannon, M. Cappelli, S. Carcangiu, P. Card, A. Cardinali, S. Carli, P. Carman, D. Carnevale, B. Carvalho, I.S. Carvalho, P. Carvalho, I. Casiraghi, F.J. Casson, C. Castaldo, J.P. Catalan, N. Catarino, F. Causa, M. Cavedon, M. Cecconello, L. Ceelen, C.D. Challis, B. Chamberlain, R. Chandra, C.S. Chang, A. Chankin, B. Chapman, P. Chauhan, M. Chernyshova, A. Chiariello, G.-C. Chira, P. Chmielewski, A. Chomiczewska, L. Chone, J. Cieslik, G. Ciraolo, D. Ciric, J. Citrin, Ł. Ciupinski, R. Clarkson, M. Cleverly, P. Coates, V. Coccorese, R. Coelho, J.W. Coenen, I.H. Coffey, A. Colangeli, L. Colas, J. Collins, S. Conroy, C. Contré, N.J. Conway, D. Coombs, P. Cooper, S. Cooper, L. Cordaro, C. Corradino, Y. Corre, G. Corrigan, D. Coster, T. Craciunescu, S. Cramp, D. Craven, R. Craven, G. Croci, D. Croft, K. Crombé, T. Cronin, N. Cruz, A. Cufar, A. Cullen, A. Dal Molin, S. Dalley, P. David, A. Davies, J. Davies, S. Davies, G. Davis, K. Dawson, S. Dawson, I. Day, G. De Tommasi, J. Deane, M. Dearing, M. De Bock, J. Decker, R. Dejarnac, E. Delabie, E. de la Cal, E. de la Luna, D. Del Sarto, A. Dempsey, W. Deng, A. Dennett, G.L. Derks, G. De Temmerman, F. Devasagayam, P. de Vries, P. Devynck, A. di Siena, D. Dickinson, T. Dickson, M. Diez, P. Dinca, T. Dittmar, L. Dittrich, J. Dobrashian, T. Dochnal, A.J.H. Donné, W. Dorland, S. Dorling, S. Dormido-Canto, R. Dotse, D. Douai, S. Dowson, R. Doyle, M. Dreval, P. Drews, G. Drummond, Ph. Duckworth, H.G. Dudding, R. Dumont, P. Dumortier, D. Dunai, T. Dunatov, M. Dunne, I. Ďuran, F. Durodié, R. Dux, T. Eade, E. Eardley, J. Edwards, T. Eich, A. Eksaeva, H. El-Haroun, R.D. Ellis, G. Ellwood, C. Elsmore, S. Emery, G. Ericsson, B. Eriksson, F. Eriksson, J. Eriksson, L.G. Eriksson, S. Ertmer, G. Evans, S. Evans, E. Fable, D. Fagan, M. Faitsch, D. Fajardo Jimenez, M. Falessi, A. Fanni, T. Farmer, I. Farquhar, B. Faugeras, S. Fazinić, N. Fedorczak, K. Felker, R. Felton, H. Fernandes, D.R. Ferreira, J. Ferreira, G. Ferrò, J. Fessey, O. Février, O. Ficker, A.R. Field, A. Figueiredo, J. Figueiredo, A. Fil, N. Fil, P. Finburg, U. Fischer, G. Fishpool, L. Fittill, M. Fitzgerald, D. Flammini, J. Flanagan, S. Foley, N. Fonnesu, M. Fontana, J.M. Fontdecaba, L. Fortuna, E. Fortuna-Zalesna, M. Fortune, C. Fowler, P. Fox, O. Franklin, E. Fransson, L. Frassinetti, R. Fresa, D. Frigione, T. Fülöp, M. Furseman, S. Gabriellini, D. Gadariya, S. Gadgil, K. Gál, S. Galeani, A. Galkowski, D. Gallart, M. Gambrioli, T. Gans, J. Garcia, M. García-Muñoz, L. Garzotti, J. Gaspar, R. Gatto, P. Gaudio, D. Gear, T. Gebhart, S. Gee, M. Gelfusa, R. George, S.N. Gerasimov, R. Gerru, G. Gervasini, M. Gethins, Z. Ghani, M. Gherendi, P.-I. Gherghina, F. Ghezzi, L. Giacomelli, C. Gibson, L. Gil, M.R. Gilbert, A. Gillgren, E. Giovannozzi, C. Giroud, G. Giruzzi, J. Goff, V. Goloborodko, R. Gomes, J.-F. Gomez, B. Gonçalves, M. Goniche, J. Gonzalez-Martin, A. Goodyear, S. Gore, G. Gorini, T. Görler, N. Gotts, E. Gow, J.P. Graves, J. Green, H. Greuner, E. Grigore, F. Griph, W. Gromelski, M. Groth, C. Grove, R. Grove, N. Gupta, S. Hacquin, L. Hägg, A. Hakola, M. Halitovs, J. Hall, C.J. Ham, M. Hamed, M.R. Hardman, Y. Haresawa, G. Harrer, J.R. Harrison, D. Harting, D.R. Hatch, T. Haupt, J. Hawes, N.C. Hawkes, J. Hawkins, S. Hazael, J. Hearmon, P. Heesterman, P. Heinrich, M. Held, W. Helou, O. Hemming, S.S. Henderson, R. Henriques, R.B. Henriques, D. Hepple, J. Herfindal, G. Hermon, J.C. Hillesheim, K. Hizanidis, A. Hjalmarsson, A. Ho, J. Hobirk, O. Hoenen, C. Hogben, A. Hollingsworth, S. Hollis, E. Hollmann, M. Hölzl, M. Hook, M. Hoppe, J. Horáček, N. Horsten, A. Horton, L.D. Horton, L. Horvath, S. Hotchin, Z. Hu, Z. Huang, E. Hubenov, A. Huber, V. Huber, T. Huddleston, G.T.A. Huijsmans, Y. Husain, P. Huynh, A. Hynes, D. Iglesias, M.V. Iliasova, M. Imríšek, J. Ingleby, P. Innocente, V. Ioannou-Sougleridis, N. Isernia, I. Ivanova-Stanik, E. Ivings, S. Jachmich, T. Jackson, A.S. Jacobsen, P. Jacquet, H. Järleblad, A. Järvinen, F. Jaulmes, N. Jayasekera, F. Jenko, I. Jepu, E. Joffrin, T. Johnson, J. Johnston, C. Jones, E. Jones, G. Jones, L. Jones, T.T.C. Jones, A. Joyce, M. Juvonen, A. Kallenbach, P. Kalnina, D. Kalupin, P. Kanth, A. Kantor, A. Kappatou, O. Kardaun, J. Karhunen, E. Karsakos, Ye.O. Kazakov, V. Kazantzidis, D.L. Keeling, W. Kelly, M. Kempenaars, D. Kennedy, K. Khan, E. Khilkevich, C. Kiefer, H.-T. Kim, J. Kim, S.H. Kim, D.B. King, D.J. Kinna, V.G. Kiptily, A. Kirjasuo, K.K. Kirov, A. Kirschner, T. Kiviniemi, G. Kizane, C. Klepper, A. Klix, G. Kneale, M. Knight, P. Knight, R. Knights, S. Knipe, U. Knoche, M. Knolker, M. Kocan, F. Köchl, G. Kocsis, J.T.W. Koenders, Y. Kolesnichenko, Y. Kominis, M. Kong, B. Kool, V. Korovin, S.B. Korsholm, B. Kos, D. Kos, M. Koubiti, Y. Kovtun, E. Kowalska-Strzęciwilk, K. Koziol, Y. Krasikov, A. Krasilnikov, V. Krasilnikov, M. Kresina, A. Kreter, K. Krieger, A. Krivska, U. Kruezi, I. Książek, H. Kumpulainen, B. Kurzan, S. Kwak, O.J. Kwon, B. Labit, M. Lacquaniti, A. Lagoyannis, L. Laguardia, A. Laing, V. Laksharam, N. Lam, H.T. Lambertz, B. Lane, M. Langley, E. Lascas Neto, E. Łaszyńska, K.D. Lawson, A. Lazaros, E. Lazzaro, G. Learoyd, C. Lee, K. Lee, S. Leerink, T. Leeson, X. Lefebvre, H.J. Leggate, J. Lehmann, M. Lehnen, D. Leichtle, F. Leipold, I. Lengar, M. Lennholm, E. Leon Gutierrez, L.A. Leppin, E. Lerche, A. Lescinskis, S. Lesnoj, L. Lewin, J. Lewis, J. Likonen, Ch. Linsmeier, X. Litaudon, E. Litherland-Smith, F. Liu, T. Loarer, A. Loarte, R. Lobel, B. Lomanowski, P.J. Lomas, J. Lombardo, R. Lorenzini, S. Loreti, V.P. Loschiavo, M. Loughlin, T. Lowe, C. Lowry, T. Luce, R. Lucock, T. Luda Di Cortemiglia, M. Lungaroni, C.P. Lungu, T. Lunt, V. Lutsenko, B. Lyons, J. Macdonald, E. Macusova, R. Mäenpää, H. Maier, J. Mailloux, S. Makarov, P. Manas, A. Manning, P. Mantica, M.J. Mantsinen, J. Manyer, A. Manzanares, Ph. Maquet, M. Maraschek, G. Marceca, G. Marcer, C. Marchetto, O. Marchuk, A. Mariani, G. Mariano, M. Marin, A. Marin Roldan, M. Marinelli, T. Markovič, L. Marot, C. Marren, S. Marsden, S. Marsen, J. Marsh, R. Marshall, L. Martellucci, A.J. Martin, C. Martin, R. Martone, S. Maruyama, M. Maslov, M. Mattei, G.F. Matthews, D. Matveev, E. Matveeva, A. Mauriya, F. Maviglia, M. Mayer, M.-L. Mayoral, S. Mazzi, C. Mazzotta, R. McAdams, P.J. McCarthy, P. McCullen, R. McDermott, D.C. McDonald, D. McGuckin, V. McKay, L. McNamee, A. McShee, D. Mederick, M. Medland, S. Medley, K. Meghani, A.G. Meigs, S. Meitner, S. Menmuir, K. Mergia, S. Mianowski, P. Middleton, J. Mietelski, K. Mikszuta-Michalik, D. Milanesio, E. Milani, E. Militello-Asp, F. Militello, J. Milnes, A. Milocco, S. Minucci, I. Miron, J. Mitchell, J. Mlynář, V. Moiseenko, P. Monaghan, I. Monakhov, A. Montisci, S. Moon, R. Mooney, S. Moradi, R.B. Morales, L. Morgan, F. Moro, J. Morris, T. Mrowetz, L. Msero, S. Munot, A. Muñoz-Perez, M. Muraglia, A. Murari, A. Muraro, B. N’Konga, Y.S. Na, F. Nabais, R. Naish, F. Napoli, E. Nardon, V. Naulin, M.F.F. Nave, R. Neu, S. Ng, M. Nicassio, D. Nicolai, A.H. Nielsen, S.K. Nielsen, D. Nina, C. Noble, C.R. Nobs, M. Nocente, H. Nordman, S. Nowak, H. Nyström, J. O’Callaghan, M. O’Mullane, C. O’Neill, C. Olde, H.J.C. Oliver, R. Olney, J. Ongena, G.P. Orsitto, A. Osipov, R. Otin, N. Pace, L.W. Packer, E. Pajuste, D. Palade, J. Palgrave, O. Pan, N. Panadero, T. Pandya, E. Panontin, A. Papadopoulos, G. Papadopoulos, G. Papp, V.V. Parail, A. Parsloe, K. Paschalidis, M. Passeri, A. Patel, A. Pau, G. Pautasso, R. Pavlichenko, A. Pavone, E. Pawelec, C. Paz-Soldan, A. Peacock, M. Pearce, I.J. Pearson, E. Peluso, C. Penot, K. Pepperell, A. Perdas, T. Pereira, E. Perelli Cippo, C. Perez von Thun, D. Perry, P. Petersson, G. Petravich, N. Petrella, M. Peyman, L. Pigatto, M. Pillon, S. Pinches, G. Pintsuk, C. Piron, A. Pironti, F. Pisano, R. Pitts, U. Planck, N. Platt, V. Plyusnin, M. Podesta, G. Pokol, F.M. Poli, O.G. Pompilian, M. Poradzinski, M. Porkolab, C. Porosnicu, G. Poulipoulis, A.S. Poulsen, I. Predebon, A. Previti, D. Primetzhofer, G. Provatas, G. Pucella, P. Puglia, K. Purahoo, O. Putignano, T. Pütterich, A. Quercia, G. Radulescu, V. Radulovic, R. Ragona, M. Rainford, P. Raj, M. Rasinski, D. Rasmussen, J. Rasmussen, J.J. Rasmussen, A. Raso, G. Rattá, S. Ratynskaia, R. Rayaprolu, M. Rebai, A. Redl, D. Rees, D. Réfy, R. Reichle, H. Reimerdes, B.C.G. Reman, C. Reux, S. Reynolds, D. Rigamonti, E. Righi, F.G. Rimini, J. Risner, J.F. Rivero-Rodriguez, C.M. Roach, J. Roberts, R. Robins, S. Robinson, D. Robson, S. Rode, P. Rodrigues, P. Rodriguez-Fernandez, S. Romanelli, J. Romazanov, E. Rose, C. Rose-Innes, R. Rossi, S. Rowe, D. Rowlands, C. Rowley, M. Rubel, G. Rubinacci, G. Rubino, M. Rud, J. Ruiz Ruiz, F. Ryter, S. Saarelma, A. Sahlberg, M. Salewski, A. Salmi, R. Salmon, F. Salzedas, F. Sanchez, I. Sanders, D. Sandiford, F. Sanni, O. Sauter, P. Sauvan, G. Schettini, A. Shevelev, A.A. Schekochihin, K. Schmid, B.S. Schmidt, S. Schmuck, M. Schneider, P.A. Schneider, N. Schoonheere, R. Schramm, D. Scoon, S. Scully, M. Segato, J. Seidl, L. Senni, J. Seo, G. Sergienko, M. Sertoli, S.E. Sharapov, R. Sharma, A. Shaw, R. Shaw, H. Sheikh, U. Sheikh, N. Shi, P. Shigin, D. Shiraki, G. Sias, M. Siccinio, B. Sieglin, S.A. Silburn, A. Silva, C. Silva, J. Silva, D. Silvagni, D. Simfukwe, J. Simpson, P. Sirén, A. Sirinelli, H. Sjöstrand, N. Skinner, J. Slater, T. Smart, R.D. Smirnov, N. Smith, P. Smith, T. Smith, J. Snell, L. Snoj, E.R. Solano, V. Solokha, C. Sommariva, K. Soni, M. Sos, J. Sousa, C. Sozzi, T. Spelzini, F. Spineanu, L. Spolladore, D. Spong, C. Srinivasan, G. Staebler, A. Stagni, I. Stamatelatos, M.F. Stamp, Ž. Štancar, P.A. Staniec, G. Stankūnas, M. Stead, B. Stein-Lubrano, A. Stephen, J. Stephens, P. Stevenson, C. Steventon, M. Stojanov, D.A. St-Onge, P. Strand, S. Strikwerda, C.I. Stuart, S. Sturgeon, H.J. Sun, S. Surendran, W. Suttrop, J. Svensson, J. Svoboda, R. Sweeney, G. Szepesi, M. Szoke, T. Tadić, B. Tal, T. Tala, P. Tamain, K. Tanaka, W. Tang, G. Tardini, M. Tardocchi, D. Taylor, A.S. Teimane, G. Telesca, A. Teplukhina, A. Terra, D. Terranova, N. Terranova, D. Testa, B. Thomas, V.K. Thompson, A. Thorman, A.S. Thrysoe, W. Tierens, R.A. Tinguely, A. Tipton, H. Todd, M. Tomeš, A. Tookey, P. Tsavalas, D. Tskhakaya, L.-P. Turică, A. Turner, I. Turner, M. Turner, M.M. Turner, G. Tvalashvili, A. Tykhyy, S. Tyrrell, A. Uccello, V. Udintsev, A. Vadgama, D.F. Valcarcel, A. Valentini, M. Valisa, M. Vallar, M. Valovic, M. Van Berkel, K.L. van de Plassche, M. van Rossem, D. Van Eester, J. Varela, J. Varje, T. Vasilopoulou, G. Vayakis, M. Vecsei, J. Vega, M. Veis, P. Veis, S. Ventre, M. Veranda, G. Verdoolaege, C. Verona, G. Verona Rinati, E. Veshchev, N. Vianello, E. Viezzer, L. Vignitchouk, R. Vila, R. Villari, F. Villone, P. Vincenzi, A. Vitins, Z. Vizvary, M. Vlad, I. Voldiner, U. Von Toussaint, P. Vondráček, B. Wakeling, M. Walker, R. Walker, M. Walsh, R. Walton, E. Wang, F. Warren, R. Warren, J. Waterhouse, C. Watts, T. Webster, M. Weiland, H. Weisen, M. Weiszflog, N. Wendler, A. West, M. Wheatley, S. Whetham, A. Whitehead, D. Whittaker, A. Widdowson, S. Wiesen, M. Willensdorfer, J. Williams, I. Wilson, T. Wilson, M. Wischmeier, A. Withycombe, D. Witts, A. Wojcik-Gargula, E. Wolfrum, R. Wood, R. Woodley, R. Worrall, I. Wyss, T. Xu, D. Yadykin, Y. Yakovenko, Y. Yang, V. Yanovskiy, R. Yi, I. Young, R. Young, B. Zaar, R.J. Zabolockis, L. Zakharov, P. Zanca, A. Zarins, D. Zarzoso Fernandez, K.-D. Zastrow, Y. Zayachuk, M. Zerbini, W. Zhang, B. Zimmermann, M. Zlobinski, A. Zocco, V.K. Zotta, M. Zuin, W. Zwingmann, and I. Zychor

Subjects
magnetic fusion, JET-ILW, D–T, tritium, alpha particles, fusion prediction, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

In 2021 JET exploited its unique capabilities to operate with T and D–T fuel with an ITER-like Be/W wall (JET-ILW). This second major JET D–T campaign (DTE2), after DTE1 in 1997, represented the culmination of a series of JET enhancements—new fusion diagnostics, new T injection capabilities, refurbishment of the T plant, increased auxiliary heating, in-vessel calibration of 14 MeV neutron yield monitors—as well as significant advances in plasma theory and modelling in the fusion community. DTE2 was complemented by a sequence of isotope physics campaigns encompassing operation in pure tritium at high T-NBI power. Carefully conducted for safe operation with tritium, the new T and D–T experiments used 1 kg of T (vs 100 g in DTE1), yielding the most fusion reactor relevant D–T plasmas to date and expanding our understanding of isotopes and D–T mixture physics. Furthermore, since the JET T and DTE2 campaigns occurred almost 25 years after the last major D–T tokamak experiment, it was also a strategic goal of the European fusion programme to refresh operational experience of a nuclear tokamak to prepare staff for ITER operation. The key physics results of the JET T and DTE2 experiments, carried out within the EUROfusion JET1 work package, are reported in this paper. Progress in the technological exploitation of JET D–T operations, development and validation of nuclear codes, neutronic tools and techniques for ITER operations carried out by EUROfusion (started within the Horizon 2020 Framework Programme and continuing under the Horizon Europe FP) are reported in (Litaudon et al Nucl. Fusion accepted), while JET experience on T and D–T operations is presented in (King et al Nucl. Fusion submitted).

Published
2024
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6. Comparison of reduced model predictions for divertor detachment onset and reattachment timescales in ASDEX Upgrade and JET experiments

Author

S.S. Henderson, M. Bernert, D. Brida, M. Cavedon, P. David, R. Dux, O. Février, P. Jacquet, A. Järvinen, A. Kallenbach, J. Karhunen, K. Kirov, M. Komm, M. Lennholm, B. Lomanowski, C. Lowry, R. McDermott, A. Meigs, H. Reimerdes, H. Sun, B. Thomas, the EUROfusion Tokamak Exploitation, the ASDEX Upgrade Team, and JET Contributors

Subjects
divertor detachment, impurity seeding, divertor reattachment, ASDEX Upgrade, JET, model validation, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Building on prior analysis of ASDEX Upgrade (AUG) experiments (Henderson et al 2023 Nucl. Fusion 63 086024), this study compares simple analytical formula predictions for divertor detachment onset and reattachment timescales in JET experiments. Detachment onset primarily scales with divertor neutral pressure, impurity concentration, power directed to the targets, machine size, and integral perpendicular power decay length. JET experiments, focusing on seeding mixtures of Ne and Ar, align with the detachment onset predictions. Radiation efficiencies among the impurities show good agreement with the model predictions, contrasting with AUG observations which suggested higher efficiency for Ar and lower efficiency for Ne. The time taken to re-ionise the neutral volume in front of the outer target in fully detached divertor conditions was measured following both abrupt increases in injected neutral beam power and, separately, cutting of the impurity gas flow. Re-ionisation of the neutrals occurs within approximately 1 s on JET, which aligns with the simple model prediction derived from AUG data. While the AUG results are not new, their comparison with the JET results enhances understanding, reinforcing confidence in using simple models to predict future reactor scenarios.

Published
2024
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7. Poloidal structure of the edge parallel flow in H-mode, L-mode and I-mode confinement regimes

Author

D.J. Cruz-Zabala, E. Viezzer, P. Cano-Megias, M. Cavedon, R. Dux, U. Plank, T. Pütterich, K. McKay, A. Rodriguez-Gonzalez, M. Garcia-Munoz, and the ASDEX Upgrade Team

Subjects
impurity, asymmetry, CXRS, flows, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Impurity profiles have been measured with the edge high field side (HFS) and low field side (LFS) charge exchange recombination spectroscopy suite at ASDEX Upgrade enabling the study of the poloidal structure of the edge parallel flow in H-mode, L-mode and I-mode. In H-mode, asymmetries in the impurity density, toroidal and poloidal rotations are found. In I-mode, only toroidal rotation asymmetries have been measured while in L-mode no asymmetries have been observed. The measured parallel flow can be divided in two components, the Pfirsch–Schlüter (PS) flow and the symmetric flow. Two different methods have been followed to determine both contributions to the parallel flow. The first method is based on the calculation of the PS flow at the HFS and LFS from the radial electric field. The second method directly provides the symmetric flow from the flux surface average (FSA) of the parallel flow. In H-mode, the methods provide different results, while in L-mode and I-mode they agree. The differences observed in H-mode between the two methods could be explained by the existence of asymmetries in the impurity density, by the non-negligible particle sources and radial losses, or by the approximations made in the calculation of the FSA of the parallel flow from measurements in two poloidal positions (midplane HFS and LFS) only.

Published
2024
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8. Divertor Tokamak Test facility project: status of design and implementation

Author

Francesco Romanelli, on behalf of DTT Contributors, D. Abate, E. Acampora, D. Agguiaro, R. Agnello, P. Agostinetti, M. Agostini, A. Aimetta, R. Albanese, G. Alberti, M. Albino, E. Alessi, S. Almaviva, M. Alonzo, R. Ambrosino, P. Andreoli, M. Angelone, M. Angelucci, C. Angioni, A. Angrisani Armenio, P. Antonini, D. Aprile, G. Apruzzese, M. Aquilini, G. Aragone, P. Arena, M. Ariola, G. Artaserse, L. Aucone, A. Augieri, F. Auriemma, J. Ayllon Guerola, N. Badodi, B. Baiocchi, L. Balbinot, C. Baldacchini, A. Balestri, T. Barberis, G. Barone, L. Barucca, M. Baruzzo, S. Begozzi, V. Belardi, F. Belli, A. Belpane, F. Beone, S. Bertolami, S. Bianucci, S. Bifaretti, S. Bigioni, W. Bin, P. Boccali, B. Boeswirth, E. Bogazzi, R. Bojoi, S. Bollanti, T. Bolzonella, F. Bombarda, M. Bonan, N. Bonanomi, A. Bonaventura, L. Boncagni, M. Bonesso, D. Bonfiglio, R. Bonifetto, D. Bonomi, D. Borgogno, T. Borzone, S. Botti, E. Boz, F. Braghin, M. Brena, S. Brezinsek, M. Brombin, A. Bruschi, S. Buonocore, P. Buratti, D. Busi, G. Calabrò, M. Caldora, G. Calvo, G. Camera, G. Campana, S. Candela, V. Candela, F. Cani, L. Cantone, F. Capaldo, S. Cappello, M. Caponero, S. Carchella, A. Cardinali, D. Carnevale, L. Carraro, C. Carrelli, V. Casalegno, I. Casiraghi, C. Castaldo, A. Castaldo, G. Castro, A. Carpignano, F. Causa, R. Cavazzana, M. Cavedon, M. Cavenago, M. Cecchini, S. Ceccuzzi, G. Celentano, L. Celona, C. Centioli, G.V. Centomani, S. Cesaroni, A.G. Chiariello, R. Chomicz, C. Cianfarani, F. Cichocki, M. Cinque, A. Cioffi, M. Ciotti, M. Cipriani, S. Ciufo, V. Claps, G. Claps, V. Coccorese, D. Coccorese, A. Colangeli, T. Coltella, F. Consoli, F. Cordella, D. Corradini, O. Costa, F. Crea, A. Cremona, F. Crescenzi, F. Crisanti, G. Cristofari, G. Croci, A. Cucchiaro, D. D’Ambrosio, M. Dal Molin, M. Dalla Palma, F. Danè, C. Day, M. De Angeli, V. De Leo, R. De Luca, E. De Marchi, G. De Marzi, G. De Masi, E. De Nardi, C. De Piccoli, G. De Sano, M. De Santis, G. De Tommasi, A. Del Nevo, A. Delfino, A. Della Corte, P. Deodati, S. Desiderati, E. Di Ferdinando, M.G. Di Florio, G. Di Gironimo, L.E. Di Grazia, V. Di Marzo, F. Di Paolo, E. Di Pietro, M. Di Pietrantonio, M. Di Prinzio, A. Di Silvestre, A. Di Zenobio, R. Dima, A. Domenichelli, A. Doria, G. Dose, S. Dubbioso, S. Dulla, I. Duran, M. Eboli, M. Elitropi, E. Emanuelli, B. Esposito, P. Ettorre, C. Fabbri, F. Fabbri, M. Fadone, M.M. Faggiano, F. Falcioni, M.V. Falessi, F. Fanale, P. Fanelli, A. Fassina, M. Favaretto, G. Favero, M. Ferraris, F. Ferrazza, C. Ferretti, A. Ferro, N. Ferron, C. Fiamozzi Zignani, L. Figini, F. Filippi, M. Filippini, A. Fimiani, M. Fincato, F. Fiorenza, D. Fiorucci, D. Flammini, F. Flora, N. Fonnesu, P. Franz, L. Frassinetti, A. Frattolillo, R. Freda, R. Fresa, A. Frescura, P. Frosi, M. Fulici, M. Furno Palumbo, V. Fusco, P. Fusco, L. Gabellier, P. Gaetani, E. Gaio, E. Gajetti, A. Galatà, J. Galdon Quiroga, D.L. Galindo Huertas, S. Gammino, G. Gandolfo, S. Garavaglia, J. Garcia Lopez, M. Garcia Muñoz, P. Gaudio, M. Gelfusa, G. Gervasini, L. Giannini, M. Giarrusso, C. Gil, F. Giorgetti, E. Giovannozzi, G. Giruzzi, L. Giudicotti, M. Gobbin, G. Gorini, G. Granucci, D. Grasso, T. Grasso, S. Grazioso, H. Greuner, G. Griva, G. Grosso, S. Guerini, J.P. Gunn, V. Hauer, J. Hidalgo Salaverri, M. Hoppe, M. Houry, M. Hoelzl, A. Iaboni, M. Iafrati, A. Iaiunese, V. Imbriani, D. Indrigo, P. Innocente, F. Koechl, B. Končar, A. Kryzhanovskyy, L. Laguardia, D.A. Lampasi, C. Lanchi, F. Lanzotti, A. Lanzotti, M. Laquaniti, F. Leone, J. Li, M. Libè, F. Lisanti, D. Liuzza, F. Locati, R. Lombroni, R. Lorenzini, P. Lorusso, L. Lotto, J. Loureiro, F. Lucca, T. Luda Di Cortemiglia, P. Maccari, G. Maddaluno, S. Magagnino, G. Manca, A. Mancini, P. Mandalà, B. Mandolesi, F. Mandrile, G. Manduchi, S. Manfrin, M. Manganelli, P. Mantica, G. Marchiori, N. Marconato, G. Marelli, A. Mariani, A. Marin, R. Marinari, M. Marinelli, F. Marino, P. Marino, D. Marocco, R. Marsilio, E. Martelli, P. Martin, F. Martinelli, G. Martini, R. Martone, A. Marucci, D. Marzullo, V. Masala, D. Mascali, F. Mascari, A. Masi, N. Massanova, S. Mastrostefano, M. Mattei, G. Mauro, S. Mauro, C. Meineri, L. Melaragni, A. Mele, P. Meller, S. Meloni, I. Menicucci, G. Messina, L. Mezi, G. Miccichè, M. Micheletti, S. Migliori, D. Milanesio, F. Milazzo, R. Milazzo, P. Minelli, S. Minucci, F. Mirizzi, M. Missirlian, D. Monarca, C. Monti, M. Mori, A. Moriani, L. Morici, A. Moro, F. Moro, P. Mosetti, R. Mozzillo, A. Murari, A. Muraro, D. Murra, P. Muscente, S. Musumeci, L. Muzzi, G.F. Nallo, F. Napoli, E. Nardon, E. Naselli, R. Neu, M. Nocente, M. Notazio, S. Nowak, E. Ocello, A. Oliva, V. Orsetti, A. Orsini, F.P. Orsitto, M. Ortino, M. Ottavi, G. Paccagnella, D. Pacella, I. Pagani, N. Paganucci, A. Pagliaro, V. Palazzolo, M. Palermo, S. Palomba, F. Panza, D. Paoletti, M. Parisi, R. Pasqualotto, S. Passarello, M. Passoni, T. Patton, L. Pelliccia, A. Peloso, A. Pepato, E. Perelli, A. Perencin, S. Peruzzo, A. Pesenti, N. Pedroni, P. Petrolini, V. Piergotti, A. Pidatella, L. Pigatto, M. Pillon, T. Pinna, S. Pipolo, S. Piras, C. Piron, L. Piron, A. Pironti, M. Pistilli, D. Placido, A. Pizzuto, P. Platania, A. Polimadei, F. Pollastrone, G.M. Polli, N. Pomaro, F. Pompili, C. Ponti, F. Porcelli, V. Prandelli, A. Previti, A. Princiotta, G. Pucino, F. Quaglia, A. Quercia, F. Raffaelli, G. Ramogida, G. Ranieri, B. Raspante, D. Ravarotto, G.L. Ravera, A. Reale, P. Rebesan, M. Recchia, D. Regine, F. Renno, B. Riccardi, D. Ricci, D. Rigamonti, M. Ripani, N. Rispoli, S. Roccella, G. Rocchi, H. Roche, M. Romanato, F. Romanelli, G. Romanelli, R. Romaniello, A. Romano, M. Romano, R. Romano, R. Rossi, G. Rubinacci, G. Rubino, S. Rubino, J. Rueda Rueda, A. Rufoloni, C. Salvia, P. Salvini, M. Scarpari, A. Salvitti, L. Salvò, S. Sandri, F. Santoro, A. Satriano, L. Savoldi, C. Scardino, G. Schettini, S. Schmuck, J. Scionti, M. Scisciò, M. Scungio, K. Sedlak, L. Senni, G. Sias, A. Sibio, A. Simonetto, L. Singh, A. Sirignano, C. Sozzi, I. Spada, S. Spagnolo, L. Spinicci, G. Spizzo, M. Spolaore, C. Stefanini, H. Strobel, F. Subba, F. Taccogna, B. Taheri, C. Tantos, A. Tarallo, M. Tarantino, G. Tardini, M. Tardocchi, P. Tarfila, A. Tenaglia, C. Terlizzi, D. Terranova, D. Testa, E. Testa, R. Testoni, V. Toigo, G. Torrisi, A. Trotta, G. Trovato, E. Tsitrone, A. Tuccillo, O. Tudisco, M. Turcato, S. Turtù, A. Uccello, M. Ugoletti, O. Uras, M. Uras, M. Utili, V. Vaccaro, F. Valentini, L. Valletti, M. Valisa, D. Van Eester, D. Vanzan, E. Vassallo, G. Vecchi, M. Vellucci, I. Venneri, G. Ventura, M. Veranda, L. Verdini, C. Verona, G. Verona Rinati, F. Veronese, N. Vianello, F. Viganò, O. Villano, R. Villari, F. Villone, P. Vincenzi, V. Vitale, F. Vivio, G. Vlad, M. Wischmeier, H.S. Wu, I. Wyss, R. Zanino, B. Zaniol, F. Zanon, A. Zappatore, G. Zavarise, P. Zito, A. Zoppoli, M. Zucchetti, M. Zuin, and P. Zumbolo

Subjects
divertor, exhaust, plasma scenarios, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

An overview is presented of the progress since 2021 in the construction and scientific programme preparation of the Divertor Tokamak Test (DTT) facility. Licensing for building construction has been granted at the end of 2021. Licensing for Cat. A radiologic source has been also granted in 2022. The construction of the toroidal field magnet system is progressing. The prototype of the 170 GHz gyrotron has been produced and it is now under test on the FALCON facility. The design of the vacuum vessel, the poloidal field coils and the civil infrastructures has been completed. The shape of the first DTT divertor has been agreed with EUROfusion to test different plasma and exhaust scenarios: single null, double null, X-divertor and negative triangularity plasmas. A detailed research plan is being elaborated with the involvement of the EUROfusion laboratories.

Published
2024
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9. Physics basis for the divertor tokamak test facility

Author

F. Crisanti, R. Ambrosino, M.V. Falessi, L. Gabellieri, G. Giruzzi, G. Granucci, P. Innocente, P. Mantica, G. Ramogida, G. Vlad, R. Albanese, E. Alessi, C. Angioni, P. Agostinetti, L. Aucone, F. Auriemma, B. Baiocchi, L. Balbinot, A. Balestri, T. Barberis, M. Baruzzo, T. Bolzonella, N. Bonanomi, D. Bonfiglio, S. Brezinsek, G. Calabrò, F. Cani, I. Casiraghi, A. Castaldo, C. Castaldo, M. Cavedon, S. Ceccuzzi, F. Cichocki, M. Ciotti, C. Day, C. De Piccoli, G. Dose, E. Emanueli, L. Frassinetti, L. Figini, V. Fusco, E. Giovannozzi, M. Gobbin, F. Koechi, A. Kryzhanovskyy, Y. Li, R. Lombroni, T. Luda, A. Mariani, P. Martin, C. Meineri, A. Murari, P. Muscente, F. Napoli, E. Nardon, R. Neu, M. Nocente, M. Notazio, S. Nowak, L. Pigatto, C. Piron, F. Porcelli, S. Roccella, G. Rubino, M. Scarpari, C. Sozzi, G. Spizzo, F. Subba, F. Taccogna, C. Tantos, D. Terranova, E. Tsitrone, A. Uccello, D. Van Eester, N. Vianello, P. Vincenzi, M. Wischmeier, and F. Zonca

Subjects
plasma, experiment, theory, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

This paper is dealing with the physics basis used for the design of the Divertor Tokamak Test facility (DTT), under construction in Frascati (DTT 2019 DTT interim design report (2019)) Italy, and with the description of the main target plasma scenarios of the device. The main goal of the facility will be the study of the power exhaust, intended as a fully integrated core-edge problem, and eventually to propose an optimized divertor for the European DEMO plant. The approach used to design the facility is described and their main features are reported, by using simulations performed by state-of-the-art codes both for the bulk and edge studies. A detailed analysis of MHD, including also the possibility to study disruption events and Energetic Particles physics is also reported. Eventually, a description of the ongoing work to build-up a Research Plan written and shared by the full EUROfusion community is presented.

Published
2024
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10. The X-Point radiating regime at ASDEX Upgrade and TCV

Author

M. Bernert, S. Wiesen, O. Février, A. Kallenbach, J.T.W. Koenders, B. Sieglin, U. Stroth, T.O.S.J. Bosman, D. Brida, M. Cavedon, P. David, M.G. Dunne, S. Henderson, B. Kool, T. Lunt, R.M. McDermott, O. Pan, A. Perek, H. Reimerdes, U. Sheikh, C. Theiler, M. van Berkel, T. Wijkamp, and M. Wischmeier

Subjects
Power exhaust, Divertor detachment, X-point radiation, Radiative scenarios, Nuclear engineering. Atomic power, TK9001-9401
Abstract

Future fusion reactors require a safe, steady-state divertor operation. With deep divertor detachment, which is typically induced by impurity seeding, the radiation concentrates in a small region at the X-point or on closed flux surfaces above the X-point. This so-called X-point radiator (XPR) moves further inside the confined region with increasing seeding and the location can be actively controlled.At AUG, the parameter space for operation with an XPR was significantly extended, using active feedback on the XPR location. The XPR is observed in nearly the whole operational space of AUG in the high-densities or high collisionality regime. ELM suppression is consistently observed in all cases where the XPR was moved to a significant height above the X-point.Direct measurements of density and temperature from the region around the XPR using the new divertor Thomson scattering system at AUG indicate that the temperature at the location of the XPR remains high (>30eV) and only the region towards the X-point cools down further. In this cold XPR core, the temperature reduces to about 1eV.An XPR is also observed in TCV by the injection of nitrogen as extrinsic impurity. This highlights that the wall material (W for AUG, C for TCV) or machine size does not play a significant role for the existence of the regime. However, the scenario appears to be less stable in TCV. First experiments show the necessity of an active control for the XPR: Depending on the wall conditions and the nitrogen wall storage, the required nitrogen seeding level to achieve an XPR changes.Both, the low temperatures measured radially outside of the radiation zone at AUG, and the lower stability of the XPR regime at TCV with the presence of carbon are consistent with the predictions of a one-dimensional model of the XPR. However, the model would predict the development of the cold XPR core, and significant radiation at the X-point might already exist before reaching this cold temperature solution.

Published
2023
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11. Divertor detachment and reattachment with mixed impurity seeding on ASDEX Upgrade

Author

S.S. Henderson, M. Bernert, D. Brida, M. Cavedon, P. David, R. Dux, O. Février, A. Järvinen, A. Kallenbach, M. Komm, R. McDermott, M. O’Mullane, the ASDEX Upgrade Team, and the EUROfusion MST1 Team

Subjects
divertor detachment, impurity seeding, divertor reattachment, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Using newly developed spectroscopic models to measure the divertor concentration of Ne and Ar, it is shown that the experimental detachment threshold on ASDEX Upgrade with Ar-only and mixtures of Ar+N or Ne+N scales as expected in comparison with an analytical equation derived by Kallenbach et al (2016 Plasma Phys. Control. Fusion 58 045013). However, it is found that Ar radiates more efficiently and Ne less efficiently in the scrape-off layer than the model predicts. By separately increasing the neutral beam injection power and cutting the impurity gas flow, it is shown that the partially detached and strongly detached X-point radiator scenarios reattach in ≈100 ms and ≈250 ms, respectively. The former timescale is set by the core energy confinement time, whereas the latter has an additional delay caused by the time required for the ionisation front to move from the X-point to the target. A simple equation with scalable geometric terms to predict the ionisation front movement time in future machines is proposed.

Published
2023
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12. Investigation of helium exhaust dynamics at the ASDEX Upgrade tokamak with full-tungsten wall

Author

A. Zito, M. Wischmeier, A. Kappatou, A. Kallenbach, F. Sciortino, V. Rohde, K. Schmid, E.T. Hinson, O. Schmitz, M. Cavedon, R.M. McDermott, R. Dux, M. Griener, U. Stroth, and the ASDEX Upgrade Team

Subjects
helium exhaust, helium compression, helium enrichment, divertor retention, pumping, wall storage, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

An efficient removal of He ash by active pumping in future fusion devices is necessary to avoid fuel dilution and not degrade the core confinement properties. Therefore, a deep understanding of the underlying physics mechanisms is mandatory. Helium exhaust has been experimentally investigated at the ASDEX Upgrade tokamak. This is an ideal test environment, thanks to the ITER-like divertor geometry, an extensive diagnostics coverage and the presence of plasma-facing components made of tungsten. The exhaust efficiency, characterized by the He compression in the divertor, was found to improve with increasing divertor neutral pressure but to degrade with detachment. A multi-reservoir particle balance model was developed to interpret the observed exhaust dynamics, accounting for plasma transport and wall retention. The limited performance of the pumping system and the efficient helium retention capability of the tungsten wall were identified to have the strongest impact on the exhaust dynamics.

Published
2023
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13. Experimental characterization of the quasi-coherent mode in EDA H-Mode and QCE scenarios at ASDEX Upgrade

Author

J. Kalis, G. Birkenmeier, P. Manz, T. Eich, M. Griener, R. Goti, M. Cavedon, L. Gil, M. Faitsch, L. Radovanovic, D. Wendler, E. Wolfrum, U. Stroth, the ASDEX Upgrade Team, and the EUROfusion MST1 Team

Subjects
fusion, plasma edge, plasma modes, EDA H-mode, quasi-continuous exhaust, quasi-coherent mode, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

The quasi-coherent mode (QCM), appearing in enhanced D $_{\alpha}$ high confinement mode (EDA H-mode) and quasi-continuous exhaust (QCE) plasmas has been analysed in detail at ASDEX Upgrade via thermal helium beam spectroscopy under various discharge parameters. In both scenarios the QCM appears to be localized close to the separatrix and to propagate in ion diamagnetic direction in the plasma frame. The poloidal wavenumber of the QCM is about $0.025 \lt k_{\theta}\rho_\mathrm{s} \lt 0.075$ and the radial wavenumber is $k_{\mathrm{r}}\approx {0}~\textrm{cm}^{-1}$ . It was found that the plasmas are generally below the ideal MHD limit at the separatrix. All the properties are consistent with ideal, resistive or kinetic ballooning modes. Simultaneous to the appearance of the QCM, higher harmonic modes can be observed in EDA H-modes, which are exclusively visible in magnetic pick-up coils and have toroidal mode numbers of up to n = 10. By performing a bicoherence analysis it was found that the higher harmonic modes and the QCM are coupling, but are disjoint phenomena. Qualitatively, the bandwidth of the QCM serves as a promising distinctive feature between QCE plasmas and EDA H-modes.

Published
2023
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14. Turbulence characterization during the suppression of edge-localized modes by magnetic perturbations on ASDEX Upgrade

Author

N. Leuthold, W. Suttrop, M. Willensdorfer, G. Birkenmeier, D. Brida, M. Cavedon, M. Dunne, G.D. Conway, R. Fischer, L. Gil, T. Happel, P. Hennequin, A. Kappatou, A. Kirk, P. Manz, R.M. McDermott, J. Vicente, H. Zohm, the ASDEX Upgrade Team, and the EUROfusion MST1 Team

Subjects
edge-localized-mode, resonant magnetic perturbation, density pump-out, turbulent particle transport, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

We study localized edge turbulence in the ASDEX Upgrade tokamak that appears if resonant magnetic perturbations (RMP) are applied to suppress edge localized modes (ELMs) in the high confinement mode. The concomitant density fluctuations are detected by microwave reflectometry at the outboard midplane. Two modes can be distinguished, (a) a broadband fluctuation below a threshold of the RMP field amplitude, and (b) a narrow-band quasi-coherent mode (QCM) above the threshold. The broadband fluctuation is toroidally spread out but disappears at the toroidal position of maximum E × B shear in the gradient region. Temporal and spatial correlation along field lines of the midplane density fluctuation and the divertor particle flux suggests that this mode is producing significant particle transport across the gradient region and into the divertor, hence contributing to the plasma density reduction that is often observed when applying RMP fields (the so-called ‘pump-out’ effect). The QCM is also toroidally localized, its radial extent grows with increasing RMP field amplitude, and leads to further increased divertor particle flux compared to the broadband mode. Our observations suggest that both modes not only play an important role in keeping the plasma density stationary in the absence of ELMs but also to reduce the plasma pressure such that the plasma edge becomes stable against ELMs.

Published
2023
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15. Parameter dependencies of the experimental nitrogen concentration required for detachment on ASDEX Upgrade and JET

Author

S.S. Henderson, M. Bernert, C. Giroud, D. Brida, M. Cavedon, P. David, R. Dux, J.R. Harrison, A. Huber, A. Kallenbach, J. Karhunen, B. Lomanowski, G. Matthews, A. Meigs, R.A. Pitts, F. Reimold, M.L. Reinke, S. Silburn, N. Vianello, S. Wiesen, and M. Wischmeier

Subjects
Impurity, Nitrogen, Divertor, Concentration, Spectroscopy, Tokamak, Nuclear engineering. Atomic power, TK9001-9401
Abstract

While current tokamak experiments are beginning to use real-time feedback control systems to manage the plasma exhaust, future tokamaks still require validation of theoretical models used to predict the threshold impurity concentration required to sufficiently reduce the power and particle fluxes to the divertor. This work exploits new spectroscopic measurements of the divertor nitrogen concentration, cN, in partially detached N2-seeded H-mode plasmas on ASDEX Upgrade (AUG) and JET with the ITER-Like Wall (JET-ILW) to test the parameter dependencies of the power flowing to the outer divertor, Pdiv,outer, and the separatrix electron density, ne,sep. A least-squares regression of the AUG measurements demonstrates that the threshold cN required for detachment scales as cN∝Pdiv,outer1.19±0.32ne,sep-2.77±0.36. This scaling of ne,sep is also consistent with the measurements from JET which, at constant Pdiv,outer, show cN∝ne,sep-2.43±0.27. The dependencies of Pdiv,outer and ne,sep is demonstrated over at least a factor of two change in both parameters and indicates a stronger dependence on ne,sep in comparison to the Lengyel model, which could be due to the assumption in this model that the heat flux channel width is independent of density. This first assessment of detachment scaling with impurity seeding highlights the need for further analysis of the systematic uncertainties of the measurement and more consistent scenarios from more tokamaks to investigate the machine size scaling.

Published
2021
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16. Inter-ELM pedestal localized fluctuations in tokamaks: Summary of multi-machine observations

Author

F.M. Laggner, A. Diallo, M. Cavedon, and E. Kolemen

Subjects
Nuclear engineering. Atomic power, TK9001-9401
Abstract

A variety of experimental studies on pedestal localized fluctuations appearing in between crashes of edge localized modes (ELMs) across several tokamaks have been reviewed and summarized. The onset of the inter-ELM fluctuations is correlated with the evolution of the pedestal gradients. Three profile recovery phases are extracted, which are interlinked with the onsets of different kinds of pedestal fluctuations. Across machines it is found that the pedestal fluctuations can be assorted into at least three categories. These are determined by the fluctuation onset in the ELM cycle, observed frequency range and radial location in the pedestal. Further, the categories might be also related to different instabilities. Similar observations at various machines may point to a underlying generation mechanism that acts similarly for presently accessible pedestal parameter ranges. Keywords: Plasma, High confinement mode (H-mode), Edge localized mode (ELM), Pedestal profiles, Edge instabilities

Published
2019
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17. An assessment of nitrogen concentrations from spectroscopic measurements in the JET and ASDEX upgrade divertor

Author

S.S. Henderson, M. Bernert, S. Brezinsek, M. Carr, M. Cavedon, R. Dux, D.S. Gahle, J. Harrison, A. Kallenbach, B. Lipschultz, B. Lomanowski, A. Meigs, M. O’Mullane, F. Reimold, M.L. Reinke, and S. Wiesen

Subjects
Nuclear engineering. Atomic power, TK9001-9401
Abstract

The impurity concentration in the tokamak divertor plasma is a necessary input for predictive scaling of divertor detachment, however direct measurements from existing tokamaks in different divertor plasma conditions are limited. To address this, we have applied a recently developed spectroscopic N II line ratio technique for measuring the N concentration in the divertor to a range of H-mode and L-mode plasma from the ASDEX Upgrade and JET tokamaks, respectively. The results from both devices show that as the power crossing the separatrix, Psep, is increased under otherwise similar core conditions (e.g. density), a higher N concentration is required to achieve the same detachment state. For example, the N concentrations at the start of detachment increase from ≈ 2% to ≈ 9% as Psep is increased from ≈ 2.5 MW to ≈ 7 MW. These results tentatively agree with scaling law predictions (e.g. Goldston et al.) motivating a further study examining the parameters which affect the N concentration required to reach detachment. Finally, the N concentrations from spectroscopy and the ratio of D and N gas valve fluxes agree within experimental uncertainty only when the vessel surfaces are fully-loaded with N. Keywords: Impurity, Nitrogen, Divertor, Concentration, Spectroscopy, Tokamak

Published
2019
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18. On the ion and electron temperature recovery after the ELM-crash at ASDEX upgrade

Author

M. Cavedon, R. Dux, T. Pütterich, E. Viezzer, E. Wolfrum, M. Dunne, E. Fable, R. Fischer, G.F. Harrer, F.M. Laggner, A.F. Mink, U. Plank, U. Stroth, M. Willensdorfer, and ASDEX Upgrade Team

Subjects
Nuclear engineering. Atomic power, TK9001-9401
Abstract

The access to fast measurements, i.e. Δt ≈ 100 µs, of the ions and the electrons during an entire edge localized cycle (ELM) reveals asymmetries in the recovery of the maximum edge gradients. Different magnetic fluctuations are found to correlate with the saturation of the edge ion temperature (Ti), electrons temperature (Te) and density (ne) gradients. In particular, while ∇Ti and ∇ne clamp roughly 3.0 ms after the ELM-crash together with the onset of mid-frequency (f ≲ 50 kHz) magnetic fluctuations, ∇Te recovers to the pre-ELM conditions only after 7.0 ms and saturates with the appearance of high frequency fluctuations (f ≈ 200 kHz). The effect of electron temperature gradient modes (ETGs) and of energy losses induced by ionization of neutrals are discussed as possible reasons for the delayed recovery of ∇Te. The onset and the suppression of ETGs qualitatively follow the requirements of an increased electron heat transport. However, gyro-kinetic simulations are necessary to quantify the impact of ETGs. On the other hand, the impact of the neutral ionization during the density build-up as an electron energy loss channel is measured to be small compared to the total electron energy. The dominant terms in the electron energy balance are instead the radiative power and the ion-electron heat exchange. Keywords: ELM, Ion temperature, ETG, Neutral ionization, Fast Charge Exchange

Published
2019
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19. Chemically assisted physical sputtering of Tungsten: Identification via the 6Π→6Σ+ transition of WD in TEXTOR and ASDEX Upgrade plasmas

Author

S. Brezinsek, A. Pospieszczyk, G. Sergienko, R. Dux, M. Cavedon, M. Faitsch, and K. Krieger

Subjects
Nuclear engineering. Atomic power, TK9001-9401
Abstract

Tungsten (W) is a preferred plasma-facing material for areas of high particle and power impact in present day and future fusion devices. The lifetime of W plasma-facing components (PFCs) under steady-state conditions is limited by erosion processes induced by energetic impinging particles such as impurities (carbon C, oxygen O, nitrogen N, etc.) and hydrogen isotopes above the threshold energy for Physical Sputtering (PS). We discovered for the first time, in addition to the bare physical sputtering process of W, a second W erosion mechanism at PFCs in TEXTOR (limiter surfaces) and ASDEX Upgrade (divertor target plates) during deuterium plasma bombardment. The tungsten deuteride molecule WD has been identified spectroscopically via the 6Π→6Σ+ transition in parallel to ordinary neutral W line emission of the WI transition (5d5(6S)6s 7S3 → 5d5(6S)6p 7P4) at λ=400.9nm used as measure to quantify the bare PS process or, more precisely, the gross erosion of W. We identified the underlying process for the molecular release as Chemically Assisted Physical Sputtering (CAPS) as observed also in the case of beryllium or lanthanum. Measurements in TEXTOR and ASDEX Upgrade showed a dependence of the WD band emission on the surface temperature - connected to the deuterium content in the near W surface - as well as on the flux and energy of impinging energetic particles. A quantification of the released WD is not yet possible due to lack of appropriate molecular data for the conversion of photons into particles, but the spatially resolved ratio of atomic (WI) and molecular photon flux (WD) indicates that the release takes place at the same time, but differently distributed along the target plates and limiters reflecting the variation in the described critical parameters (impinging ion flux, ion impact energy, and material temperature) along the surface. The plasma conditions in front of the interaction zone are in both cases fully ionising with an electron temperature Te > 10eV, thus, recombination into WD can be excluded. Keywords: Tungsten, TEXTOR, ASDEX Upgrade, Physical Sputtering, Divertor

Published
2019
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20. Impact of plasma-wall interaction and exhaust on the EU-DEMO design

Author

F. Maviglia, M. Siccinio, C. Bachmann, W. Biel, M. Cavedon, E. Fable, G. Federici, M. Firdaouss, J. Gerardin, V. Hauer, I. Ivanova-Stanik, F. Janky, R. Kembleton, F. Militello, F. Subba, S. Varoutis, and C. Vorpahl

Subjects
EU-DEMO, Limiters, Disruptions, Divertor reattachment, ELMs, Transients, Nuclear engineering. Atomic power, TK9001-9401
Abstract

In the present work, the role of plasma facing components protection in driving the EU-DEMO design will be reviewed, focusing on steady-state and, especially, on transients. This work encompasses both the first wall (FW) as well as the divertor. In fact, while the ITER divertor heat removal technology has been adopted, the ITER FW concept has been shown in the past years to be inadequate for EU-DEMO. This is due to the higher foreseen irradiation damage level, which requires structural materials (like Eurofer) able to withstand more than 5 dpa of neutron damage. This solution, however, limits the tolerable steady-state heat flux to ~1 MW/m2, i.e. a factor 3–4 below the ITER specifications. For this reason, poloidally and toroidally discontinuous protection limiters are implemented in EU-DEMO. Their role consists in reducing the heat load on the FW due to charged particles, during steady state and, more importantly, during planned and off-normal plasma transients. Concerning the divertor configuration, EU-DEMO currently assumes an ITER-like, lower single null (LSN) divertor, with seeded impurities for the dissipation of the power. However, this concept has been shown by numerous simulations in the past years to be marginal during steady-state (where a detached divertor is necessary to maintain the heat flux below the technological limit and to avoid excessive erosion) and unable to withstand some relevant transients, such as large ELMs and accidental loss of detachment. Various concepts, deviating from the ITER design, are currently under investigation to mitigate such risks, for example in-vessel coils for strike point sweeping in case of reattachment, as well as alternative divertor configurations. Finally, a broader discussion on the impact of divertor protection on the overall machine design is presented.

Published
2021
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21. Study of detachment in future ASDEX Upgrade alternative divertor configurations by means of EMC3-EIRENE

Author

T. Lunt, M. Bernert, D. Brida, M. Cavedon, P. David, M. Faitsch, Y. Feng, M. Griener, A. Herrmann, B. Kurzan, O. Pan, U. Plank, D. Silvagni, M. Teschke, M. Willensdorfer, M. Wischmeier, E. Wolfrum, and I. Zammuto

Subjects
Power exhaust, Detachment, ASDEX Upgrade, EMC3-EIRENE, Alternative divertor configuration, Snowflake, Nuclear engineering. Atomic power, TK9001-9401
Abstract

ASDEX Upgrade is preparing a hardware modification of its upper divertor in order to study alternative divertor configurations, like the X-divertor (XD) and the snowflake divertor (SF), that are discussed as a possible solution for the power exhaust problem. Experiments characterizing the current upper divertor in single-null (SN) configuration before and during detachment were carried out recently and interpreted by EMC3-EIRENE (Lunt et al., 2020) now including volumetric recombination. In continuation of these studies we here report on further simulations with this code extrapolating these conditions to the future upper divertor. For the same transport parameters, input power and upstream separatrix density for which the outer target (OT) of the SN is attached, the XD and SF show significant detachment at the OT accompanied by a reduction of the parallel heat flux by a factor of more than five. Despite the shallow field line incidence angles in the XD configuration the intrinsic 3D error fields from the current feeds only cause toroidal variations of the power fluxes of the order of 10%. With a hypothetical misalignment of the divertor coils by 3 cm substantial asymmetries in the power deposition profile are found, however, even those vanish when going to detached plasma conditions. In order to fully detach the plasma at the OT in the SF configuration impurities, here in the form of nitrogen, need to be puffed directly into the region of the secondary X-point in the simulation.

Published
2021
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22. ERO modelling of net and gross erosion of marker samples exposed to L-mode plasmas on ASDEX Upgrade

Author

A. Hakola, A. Keitaanranta, H. Kumpulainen, A. Lahtinen, J. Likonen, M. Balden, M. Cavedon, K. Krieger, M. Airila, and M. Groth

Subjects
Erosion, Material migration, ASDEX Upgrade, L-mode, Marker samples, Nuclear engineering. Atomic power, TK9001-9401
Abstract

In this paper, we report experimental and numerical investigations of gross and net erosion of gold (Au) and molybdenum (Mo), proxies for the common plasma-facing material tungsten (W), during L-mode plasma discharges in deuterium (D) in the outer strike-point region of the ASDEX Upgrade tokamak. To this end, erosion profiles of different marker spots (for Au, dimensions 1 × 1 and 5 × 5 mm2) and marker coatings (for Mo) have been determined and modelled using the ERO code. The smaller marker spots were designed to quantify the gross-erosion rate while on the bigger markers local prompt re-deposition of Au allowed obtaining data on net erosion.The experimental results indicate relatively uniform erosion profiles across the marker spots or coatings, very little re-deposition elsewhere, and the largest erosion taking place close to the strike point. Compared to W, the markers show up to 15 times higher net erosion but no major differences in the poloidal migration lengths of Au and W can be seen. Gold thus appears to be a proper choice for studying migration of W in the divertor region.The ERO simulations with different background plasmas are able to reproduce the main features of the experimental net erosion profile of Au. Of the studied parameters, electron temperature has the strongest impact on erosion: doubling the temperature enhances erosion by a factor of 2.5–3. In contrast, for Mo, the simulated net erosion is ~ 3 times smaller than what experimental data indicate. The discrepancies can be attributed to the deviations of the background plasma profiles from the measured ones as well as to the applied models or approximations for the ion temperature, plasma potential, and sheath characteristics in ERO. In addition, the surrounding areas of the marker samples being covered with impurities and W from previous experiments may have considerably reduced the actual re-deposition of Mo.All the simulations predict a toroidal tail of re-deposited particles, downstream of the markers, but the particle density seems to be below the experimental detection threshold. The comparison between the 1 × 1 mm2 and 5 × 5 mm2 marker spots further reveal that re-deposition drops from >50% to

Published
2020
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23. SOLPS-ITER simulations of an X-point radiator in the ASDEX Upgrade tokamak

Author

O. Pan, M. Bernert, T. Lunt, M. Cavedon, B. Kurzan, S. Wiesen, M. Wischmeier, U. Stroth, and the ASDEX Upgrade Team

Subjects
X-point radiator, SOLPS-ITER, power exhaust, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

The X-point radiator (XPR) is an attractive scenario that may contribute to solving the power exhaust problem in future fusion devices. The 2D transport code SOLPS-ITER was applied to reproduce the experimentally measured plasma condition with an XPR in the ASDEX Upgrade tokamak and to compare with a reduced model. Neutrals penetrating from the adjoining cold divertor region and the large connection length near the X-point play an important role in initiating an XPR. However, once such a radiator is created, it persists even if the fueling and impurity seeding rates were reduced. The redistribution of plasma density and radiation near the X-point caused by fluid drifts at the XPR was studied in the simulation.

Published
2022
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24. Expanding the role of impurity spectroscopy for investigating the physics of high-Z dissipative divertors

Author

M.L. Reinke, A. Meigs, E. Delabie, R. Mumgaard, F. Reimold, S. Potzel, M. Bernert, D. Brunner, J. Canik, M. Cavedon, I. Coffey, E. Edlund, J. Harrison, B. LaBombard, K. Lawson, B. Lomanowski, J. Lore, M. Stamp, J. Terry, and E. Viezzer

Subjects
Nuclear engineering. Atomic power, TK9001-9401
Abstract

New techniques that attempt to more fully exploit spectroscopic diagnostics in the divertor and pedestal region during highly dissipative scenarios are demonstrated using experimental results from recent low-Z seeding experiments on Alcator C-Mod, JET and ASDEX Upgrade. To exhaust power at high parallel heat flux, q∥ > 1 GW/m2, while minimizing erosion, reactors with solid, high-Z plasma facing components (PFCs) are expected to use extrinsic impurity seeding. Due to transport and atomic physics processes which impact impurity ionization balance, so-called ‘non-coronal’ effects, we do not accurately know and have yet to demonstrate the maximum q∥ which can be mitigated in a tokamak. Radiation enhancement for nitrogen is shown to arise primarily from changes in Li- and Be-like charge states on open field lines, but also through transport-driven enhancement of H- and He-like charge states in the pedestal region. Measurements are presented from nitrogen seeded H-mode and L-mode plasmas where emission from N1+ through N6+ are observed. Active charge exchange spectroscopy of partially ionized low-Z impurities in the plasma edge is explored to measure N5+ and N6+ within the confined plasma, while passive UV and visible spectroscopy is used to measure N1+-N4+ in the boundary. Examples from recent JET and Alcator C-Mod experiments which employ nitrogen seeding highlight how improving spectroscopic coverage can be used to gain empirical insight and provide more data to validate boundary simulations.

Published
2017
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25. SOLPS-ITER simulations of an X-point radiator in the ASDEX Upgrade tokamak

Author

O. Pan, M. Bernert, T. Lunt, M. Cavedon, B. Kurzan, S. Wiesen, M. Wischmeier, U. Stroth, the ASDEX Upgrade Team, ASDEX Upgrade Team, Max Planck Institute for Plasma Physics, Max Planck Society, Pan, O, Bernert, M, Lunt, T, Cavedon, M, Kurzan, B, Wiesen, S, Wischmeier, M, and Stroth, U

Subjects
Nuclear and High Energy Physics, power exhaust, Paper, X-point radiator, SOLPS-ITER, Condensed Matter Physics, ddc
Abstract

The X-point radiator (XPR) is an attractive scenario that may contribute to solving the power exhaust problem in future fusion devices. The 2D transport code SOLPS-ITER was applied to reproduce the experimentally measured plasma condition with an XPR in the ASDEX Upgrade tokamak and to compare with a reduced model. Neutrals penetrating from the adjoining cold divertor region and the large connection length near the X-point play an important role in initiating an XPR. However, once such a radiator is created, it persists even if the fueling and impurity seeding rates were reduced. The redistribution of plasma density and radiation near the X-point caused by fluid drifts at the XPR was studied in the simulation.

Published
2023

26. Overview of L- to H-mode transition experiments at ASDEX Upgrade

Author

U Plank, R M McDermott, G Birkenmeier, N Bonanomi, M Cavedon, G D Conway, T Eich, M Griener, O Grover, P A Schneider, M Willensdorfer, Plank, U, Mcdermott, R, Birkenmeier, G, Bonanomi, N, Cavedon, M, Conway, G, Eich, T, Griener, M, Grover, O, Schneider, P, Willensdorfer, M, and ASDEX Upgrade Team, Max Planck Institute for Plasma Physics, Max Planck Society

Subjects
Nuclear Energy and Engineering, overviews, ASDEX Upgrade, Condensed Matter Physics, L-H transition
Abstract

This paper presents an overview of results from L–H transition experiments that were performed at ASDEX Upgrade (AUG) with the aim of identifying the underlying mechanisms leading to H-mode confinement. With a broad variety of experiments and new diagnostic techniques, as well as modeling efforts, AUG has contributed substantially to improving our understanding of the L–H transition over the past years. In this review, the important roles of the ion heat channel and the edge radial electric field (E r ) in the L–H transition physics are brought into context with known dependencies of the H-mode power threshold ( P L H ), such as the impact of wall material, magnetic perturbations, and the magnetic configuration. Furthermore, experimental and theoretical results obtained at AUG on the L-mode edge turbulence are connected to the mean-field E r and its related shear flow. This led to a deeper understanding of the I-phase plasma regime, has resolved the so-called isotope effect of P L H , and led to the development of a semi-analytical model that can describe AUG’s experimental observations of the L–H transition together with the L- and H-mode density limits.

Published
2023

27. Non-parametric inference of impurity transport coefficients in the ASDEX Upgrade tokamak

Author

T. Nishizawa, R. Dux, R.M. McDermott, F. Sciortino, M. Cavedon, C. Schuster, E. Wolfrum, U. von Toussaint, A.Jansen Van Vuuren, D.J. Cruz-Zabala, P. Cano-Megias, C. Moon, null the ASDEX Upgrade Team, European Commission, ASDEX Upgrade Team, Max Planck Institute for Plasma Physics, Max Planck Society, Nishizawa, T, Dux, R, Mcdermott, R, Sciortino, F, Cavedon, M, Schuster, C, Wolfrum, E, Von Toussaint, U, Van Vuuren, A, Cruz-Zabala, D, Cano-Megias, P, Moon, C, Universidad de Sevilla. Departamento de Ingeniería Energética, Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, and Universidad de Sevilla. FQM402: Ciencias y Tecnologías del Plasma y el Espacio

Subjects
Nuclear and High Energy Physics, Charge exchange recombination spectroscopy, Bayesian inference, Paper, tokamak, impurity, charge exchange recombination spectroscopy, Condensed Matter Physics, Impurity, Tokamaks, ddc
Abstract

We present a non-parametric inference of impurity transport coefficients by using charge exchange recombination spectroscopy measurements of Ne X, Ne VIII, O VIII, and C VI lines. Due to their close atomic numbers, neon, oxygen and carbon impurity ions are assumed to have the same diffusion coefficient D and convection velocity v. Unlike conventional techniques that modulate or perturb the impurity contents, we employ a quasi-stationary plasma with static impurity profiles. Since the ratio of v to D only describes the equilibrated profile of the sum of all impurity charge states, steady-state measurements can still decouple D and v if different charge states are simultaneously observed. We have formulated a non-parametric analysis framework based on the Bayesian probability theory and conducted transport coefficient measurements for a Type III ELMy H-mode plasma at ASDEX Upgrade. The charge exchange reactions with the background neutrals, which are known to affect the impurity charge state balance, are taken into account by introducing additional free parameters. While D at the pedestal is close to the neoclassical level ( < 1 m s-2), a large diffusion coefficient and a strong outward convection are inferred right inside the pedestal top., 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.

Published
2022

28. 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

29. Validation of low-Z impurity transport theory using boron perturbation experiments at ASDEX upgrade

Author

R.M. McDermott, C. Angioni, M. Cavedon, A. Kappatou, R. Dux, R. Fischer, P. Manas, null the ASDEX Upgrade Team, Mcdermott, R, Angioni, C, Cavedon, M, Kappatou, A, Dux, R, Fischer, R, Manas, P, and ASDEX Upgrade Team, Max Planck Institute for Plasma Physics, Max Planck Society

Subjects
Nuclear and High Energy Physics, impurity transport, 0103 physical sciences, gyrokinetic modeling, boron transport, perturbation experiment, 010306 general physics, Condensed Matter Physics, modulation experiment, 01 natural sciences, turbulent transport, 010305 fluids & plasmas
Abstract

An experimental technique has been developed at ASDEX upgrade (AUG) to separately identify the diffusive and convective components of the boron particle flux. Using this technique a database of B transport coefficients has been assembled that shows that the normalized ion temperature gradient ( R / L T i ) is the strongest organizing parameter for both the B diffusion and convection and large R / L T i is a necessary ingredient to obtain hollow B density profiles in AUG. This database also shows that large changes in the applied neutral beam injection (NBI) have a relatively small impact on impurity transport compared to similar changes in electron cyclotron resonance heating (ECRH). Even low levels of ECRH power dramatically increase both the diffusive and convective fluxes and lead to peaking of the impurity density profile. Comparisons to a combination of neoclassical and quasi-linear gyrokinetic simulations show good agreement in the measured and predicted diffusion coefficients. The outward convection measured in NBI dominated plasmas, however, is not well captured by the simulations, despite the inclusion of fast ions. In contrast, the convection is reasonably well reproduced for plasmas with flat or peaked boron density profiles. This dataset provides an excellent experimental validation of the non-monotonic, predicted, convective-particle-flux created by the combination of pure-pinch, thermo-diffusion, and roto-diffusion. In addition, this dataset demonstrates a non-monotonic dependence of the experimental particle diffusivity to ion heat conductivity (D/χ i) in qualitative agreement with theoretical predictions.

Published
2022

30. Overview of the TCV tokamak experimental programme

Author

H. Reimerdes, M. Agostini, E. Alessi, S. Alberti, Y. Andrebe, H. Arnichand, J. Balbin, F. Bagnato, M. Baquero-Ruiz, M. Bernert, W. Bin, P. Blanchard, T.C. Blanken, J.A. Boedo, D. Brida, S. Brunner, C. Bogar, O. Bogar, T. Bolzonella, F. Bombarda, F. Bouquey, C. Bowman, D. Brunetti, J. Buermans, H. Bufferand, L. Calacci, Y. Camenen, S. Carli, D. Carnevale, F. Carpanese, F. Causa, J. Cavalier, M. Cavedon, J.A. Cazabonne, J. Cerovsky, R. Chandra, A. Chandrarajan Jayalekshmi, O. Chellaï, P. Chmielewski, D. Choi, G. Ciraolo, I.G.J. Classen, S. Coda, C. Colandrea, A. Dal Molin, P. David, M.R. de Baar, J. Decker, W. Dekeyser, H. de Oliveira, D. Douai, M. Dreval, M.G. Dunne, B.P. Duval, S. Elmore, O. Embreus, F. Eriksson, M. Faitsch, G. Falchetto, M. Farnik, A. Fasoli, N. Fedorczak, F. Felici, O. Février, O. Ficker, A. Fil, M. Fontana, E. Fransson, L. Frassinetti, I. Furno, D.S. Gahle, D. Galassi, K. Galazka, C. Galperti, S. Garavaglia, M. Garcia-Munoz, B. Geiger, M. Giacomin, G. Giruzzi, M. Gobbin, T. Golfinopoulos, T. Goodman, S. Gorno, G. Granucci, J.P. Graves, M. Griener, M. Gruca, T. Gyergyek, R. Haelterman, A. Hakola, W. Han, T. Happel, G. Harrer, J.R. Harrison, S. Henderson, G.M.D. Hogeweij, J.-P. Hogge, M. Hoppe, J. Horacek, Z. Huang, A. Iantchenko, P. Innocente, K. Insulander Björk, C. Ionita-Schrittweiser, H. Isliker, A. Jardin, R.J.E. Jaspers, R. Karimov, A.N. Karpushov, Y. Kazakov, M. Komm, M. Kong, J. Kovacic, O. Krutkin, O. Kudlacek, U. Kumar, R. Kwiatkowski, B. Labit, L. Laguardia, J.T. Lammers, E. Laribi, E. Laszynska, A. Lazaros, O. Linder, B. Linehan, B. Lipschultz, X. Llobet, J. Loizu, T. Lunt, E. Macusova, Y. Marandet, M. Maraschek, G. Marceca, C. Marchetto, S. Marchioni, E.S. Marmar, Y. Martin, L. Martinelli, F. Matos, R. Maurizio, M.-L. Mayoral, D. Mazon, V. Menkovski, A. Merle, G. Merlo, H. Meyer, K. Mikszuta-Michalik, P.A. Molina Cabrera, J. Morales, J.-M. Moret, A. Moro, D. Moulton, H. Muhammed, O. Myatra, D. Mykytchuk, F. Napoli, R.D. Nem, A.H. Nielsen, M. Nocente, S. Nowak, N. Offeddu, J. Olsen, F.P. Orsitto, O. Pan, G. Papp, A. Pau, A. Perek, F. Pesamosca, Y. Peysson, L. Pigatto, C. Piron, M. Poradzinski, L. Porte, T. Pütterich, M. Rabinski, H. Raj, J.J. Rasmussen, G.A. Rattá, T. Ravensbergen, D. Ricci, P. Ricci, N. Rispoli, F. Riva, J.F. Rivero-Rodriguez, M. Salewski, O. Sauter, B.S. Schmidt, R. Schrittweiser, S. Sharapov, U.A. Sheikh, B. Sieglin, M. Silva, A. Smolders, A. Snicker, C. Sozzi, M. Spolaore, A. Stagni, L. Stipani, G. Sun, T. Tala, P. Tamain, K. Tanaka, A. Tema Biwole, D. Terranova, J.L. Terry, D. Testa, C. Theiler, A. Thornton, A. Thrysøe, H. Torreblanca, C.K. Tsui, D. Vaccaro, M. Vallar, M. van Berkel, D. Van Eester, R.J.R. van Kampen, S. Van Mulders, K. Verhaegh, T. Verhaeghe, N. Vianello, F. Villone, E. Viezzer, B. Vincent, I. Voitsekhovitch, N.M.T. Vu, N. Walkden, T. Wauters, H. Weisen, N. Wendler, M. Wensing, F. Widmer, S. Wiesen, M. Wischmeier, T.A. Wijkamp, D. Wünderlich, C. Wüthrich, V. Yanovskiy, J. Zebrowski, the EUROfusion MST1 Team, EUROfusion MST1 Team, Control Systems Technology, Liquid metal heat shields, Science and Technology of Nuclear Fusion, Group Heemels, Mechanical Engineering, Data Mining, EAISI Health, ICMS Affiliated, EAISI High Tech Systems, Applied Physics and Science Education, Reimerdes, H, Agostini, M, Alessi, E, Alberti, S, Andrebe, Y, Arnichand, H, Balbin, J, Bagnato, F, Baquero-Ruiz, M, Bernert, M, Bin, W, Blanchard, P, Blanken, T, Boedo, J, Brida, D, Brunner, S, Bogar, C, Bogar, O, Bolzonella, T, Bombarda, F, Bouquey, F, Bowman, C, Brunetti, D, Buermans, J, Bufferand, H, Calacci, L, Camenen, Y, Carli, S, Carnevale, D, Carpanese, F, Causa, F, Cavalier, J, Cavedon, M, Cazabonne, J, Cerovsky, J, Chandra, R, Chandrarajan Jayalekshmi, A, Chellai, O, Chmielewski, P, Choi, D, Ciraolo, G, Classen, I, Coda, S, Colandrea, C, Dal Molin, A, David, P, De Baar, M, Decker, J, Dekeyser, W, De Oliveira, H, Douai, D, Dreval, M, Dunne, M, Duval, B, Elmore, S, Embreus, O, Eriksson, F, Faitsch, M, Falchetto, G, Farnik, M, Fasoli, A, Fedorczak, N, Felici, F, Fevrier, O, Ficker, O, Fil, A, Fontana, M, Fransson, E, Frassinetti, L, Furno, I, Gahle, D, Galassi, D, Galazka, K, Galperti, C, Garavaglia, S, Garcia-Munoz, M, Geiger, B, Giacomin, M, Giruzzi, G, Gobbin, M, Golfinopoulos, T, Goodman, T, Gorno, S, Granucci, G, Graves, J, Griener, M, Gruca, M, Gyergyek, T, Haelterman, R, Hakola, A, Han, W, Happel, T, Harrer, G, Harrison, J, Henderson, S, Hogeweij, G, Hogge, J, Hoppe, M, Horacek, J, Huang, Z, Iantchenko, A, Innocente, P, Insulander Bjork, K, Ionita-Schrittweiser, C, Isliker, H, Jardin, A, Jaspers, R, Karimov, R, Karpushov, A, Kazakov, Y, Komm, M, Kong, M, Kovacic, J, Krutkin, O, Kudlacek, O, Kumar, U, Kwiatkowski, R, Labit, B, Laguardia, L, Lammers, J, Laribi, E, Laszynska, E, Lazaros, A, Linder, O, Linehan, B, Lipschultz, B, Llobet, X, Loizu, J, Lunt, T, Macusova, E, Marandet, Y, Maraschek, M, Marceca, G, Marchetto, C, Marchioni, S, Marmar, E, Martin, Y, Martinelli, L, Matos, F, Maurizio, R, Mayoral, M, Mazon, D, Menkovski, V, Merle, A, Merlo, G, Meyer, H, Mikszuta-Michalik, K, Molina Cabrera, P, Morales, J, Moret, J, Moro, A, Moulton, D, Muhammed, H, Myatra, O, Mykytchuk, D, Napoli, F, Nem, R, Nielsen, A, Nocente, M, Nowak, S, Offeddu, N, Olsen, J, Orsitto, F, Pan, O, Papp, G, Pau, A, Perek, A, Pesamosca, F, Peysson, Y, Pigatto, L, Piron, C, Poradzinski, M, Porte, L, Putterich, T, Rabinski, M, Raj, H, Rasmussen, J, Ratta, G, Ravensbergen, T, Ricci, D, Ricci, P, Rispoli, N, Riva, F, Rivero-Rodriguez, J, Salewski, M, Sauter, O, Schmidt, B, Schrittweiser, R, Sharapov, S, Sheikh, U, Sieglin, B, Silva, M, Smolders, A, Snicker, A, Sozzi, C, Spolaore, M, Stagni, A, Stipani, L, Sun, G, Tala, T, Tamain, P, Tanaka, K, Tema Biwole, A, Terranova, D, Terry, J, Testa, D, Theiler, C, Thornton, A, Thrysoe, A, Torreblanca, H, Tsui, C, Vaccaro, D, Vallar, M, Van Berkel, M, Van Eester, D, Van Kampen, R, Van Mulders, S, Verhaegh, K, Verhaeghe, T, Vianello, N, Villone, F, Viezzer, E, Vincent, B, Voitsekhovitch, I, Vu, N, Walkden, N, Wauters, T, Weisen, H, Wendler, N, Wensing, M, Widmer, F, Wiesen, S, Wischmeier, M, Wijkamp, T, Wunderlich, D, Wuthrich, C, Yanovskiy, V, and Zebrowski, J

Subjects
Nuclear and High Energy Physics, Tokamak, feedback-control, Nuclear fusion, TCV, EUROfusion, ddc:620, plasmas, Condensed Matter Physics, tokamak, nuclear fusion, QC
Abstract

The tokamak à configuration variable (TCV) continues to leverage its unique shaping capabilities, flexible heating systems and modern control system to address critical issues in preparation for ITER and a fusion power plant. For the 2019–20 campaign its configurational flexibility has been enhanced with the installation of removable divertor gas baffles, its diagnostic capabilities with an extensive set of upgrades and its heating systems with new dual frequency gyrotrons. The gas baffles reduce coupling between the divertor and the main chamber and allow for detailed investigations on the role of fuelling in general and, together with upgraded boundary diagnostics, test divertor and edge models in particular. The increased heating capabilities broaden the operational regime to include T e/T i ∼ 1 and have stimulated refocussing studies from L-mode to H-mode across a range of research topics. ITER baseline parameters were reached in type-I ELMy H-modes and alternative regimes with ‘small’ (or no) ELMs explored. Most prominently, negative triangularity was investigated in detail and confirmed as an attractive scenario with H-mode level core confinement but an L-mode edge. Emphasis was also placed on control, where an increased number of observers, actuators and control solutions became available and are now integrated into a generic control framework as will be needed in future devices. The quantity and quality of results of the 2019–20 TCV campaign are a testament to its successful integration within the European research effort alongside a vibrant domestic programme and international collaborations.

Published
2022

31. Quasicontinuous Exhaust Scenario for a Fusion Reactor: The Renaissance of Small Edge Localized Modes

Author

G F, Harrer, M, Faitsch, L, Radovanovic, E, Wolfrum, C, Albert, A, Cathey, M, Cavedon, M, Dunne, T, Eich, R, Fischer, M, Griener, M, Hoelzl, B, Labit, H, Meyer, F, Aumayr, The Asdex Upgrade Team, The EUROfusion Mst Team, Harrer, G, Faitsch, M, Radovanovic, L, Wolfrum, E, Albert, C, Cathey, A, Cavedon, M, Dunne, M, Eich, T, Fischer, R, Griener, M, Hoelzl, M, Labit, B, Meyer, H, Aumayr, F, ASDEX Upgrade Team, Max Planck Institute for Plasma Physics, Max Planck Society, and EUROfusion MST1 Team

Subjects
Plasma Physics (physics.plasm-ph), Physics::Plasma Physics, General Physics and Astronomy, FOS: Physical sciences, Plasma, Fusion, Physics - Plasma Physics
Abstract

Tokamak operational regimes with small edge localized modes (ELMs) could be a solution to the problem of large transient heat loads in future fusion reactors because they provide quasi-continuous exhaust while keeping a good plasma confinement. A ballooning mode mechanism near the last closed flux surface (LCFS) governed by an interplay of the pressure gradient and the magnetic shear there has been proposed for small ELMs in high density ASDEX Upgrade and TCV discharges. In this manuscript we explore different factors relevant for plasma edge stability in a wide range of edge safety factors by changing the connection length between the good and the bad curvature side. Simultaneously this influences the stabilizing effect of the local magnetic shear close to the LCFS as well as the $E \times B$ flow shear. Ideal ballooning stability calculations with the HELENA code reveal that small ELM plasmas are indeed unstable against ballooning modes very close to the LCFS but can exhibit second ballooning stability in the steep gradient region which correlates with enhanced confinement. We also present first non-linear simulations of small ELM regimes with the JOREK code including the $E \times B$ shear which indeed develop ballooning like fluctuations in the high triangularity limit. In the region where the small ELMs originate the dimensionless parameters are very similar in our investigated discharges and in a reactor, making this regime the ideal exhaust scenario for a future reactor.

Published
2022

32. Experimental investigation of L- and H-mode detachment via the divertor Thomson scattering at ASDEX Upgrade

Author

M. Cavedon, B. Kurzan, M. Bernert, D. Brida, R. Dux, M. Griener, S. Henderson, E. Huett, T. Nishizawa, T. Lunt, O. Pan, U. Stroth, M. Wischmeier, E. Wolfrum, null the ASDEX Upgrade Team, Cavedon, M, Kurzan, B, Bernert, M, Brida, D, Dux, R, Griener, M, Henderson, S, Huett, E, Nishizawa, T, Lunt, T, Pan, O, Stroth, U, Wischmeier, M, Wolfrum, E, and ASDEX Upgrade Team, Max Planck Institute for Plasma Physics, Max Planck Society

Subjects
H-mode, Nuclear and High Energy Physics, divertor Thomson scattering, detachment, divertor, L-mode, Paper, Condensed Matter Physics, ddc
Abstract

The capabilities of the newly installed divertor Thomson Scattering (DTS) diagnostic (Kurzan et al 2021 J. Inst. 16 C09012) at ASDEX Upgrade (AUG) have been demonstrated by measuring 2D electron densities n e and temperatures T e from attached to fully detached divertor conditions in L- and H-mode. The collected dataset is a breakthrough for divertor studies at AUG in which such measurements have been so far missing. Besides highlighting the strengths and limits of the DTS system, this work provides confirmations and new insights into detachment physics. The transition between partial and pronounced detachment correlates with a 2D redistribution of the electron density from the inner to the outer divertor in both L- and H-mode. In pronounced detachment, a strong parallel pressure gradient could be confirmed throughout the complete SOL. Finally, measurements of n e and T e of a stable X-point radiator revealed local temperatures as low as 1 eV within the confined plasma, whereas the pressure is shown to be constant on closed field lines.

Published
2022

33. Model for access and stability of the X-point radiator and the threshold for marfes in tokamak plasmas

Author

U. Stroth, M. Bernert, D. Brida, M. Cavedon, R. Dux, E. Huett, T. Lunt, O. Pan, M. Wischmeier, the ASDEX Upgrade Team, ASDEX Upgrade Team, Max Planck Institute for Plasma Physics, Max Planck Society, Stroth, U, Bernert, M, Brida, D, Cavedon, M, Dux, R, Huett, E, Lunt, T, Pan, O, and Wischmeier, M

Subjects
disruption control, Nuclear and High Energy Physics, exhaust, Paper, X-point radiator, divertor detachment, marfe, Condensed Matter Physics, ddc
Abstract

Based on particle and energy balances, a reduced model is derived for the physical mechanisms leading to the occurrence of stable and unstable X-point radiators (XPRs), the latter also known as marfes. The leading roles of the neutral deuterium density in the divertor region for initiating XPRs is highlighted. An access condition is formulated whose parameter dependencies are consistent with experimental observations and which could also apply to the process of divertor detachment. With an exponential increase of the recombination rate at low temperature, the XPR becomes magnetohydrodynamically unstable, leading to a marfe and, possibly, to a disruption. A critical density for marfe occurrence is formulated with the upstream density and safety factor as leading parameters, as in the experiment. Marfes are predicted to be more likely in carbon devices than in impurity-seeded plasmas in tungsten devices. The edge plasma parameter domain where marfes occur resembles that used for active marfe avoidance schemes. Both the XPR and marfe occurrence parameter can be used to guide active discharge control.

Published
2022

34. The dependence of confinement on the isotope mass in the core and the edge of AUG and JET-ILW H-mode plasmas

Author

P.A. Schneider, C. Angioni, L. Frassinetti, L. Horvath, M. Maslov, F. Auriemma, M. Cavedon, C.D. Challis, E. Delabie, M.G. Dunne, J.M. Fontdecaba, J. Hobirk, A. Kappatou, D.L. Keeling, B. Kurzan, M. Lennholm, B. Lomanowski, C.F. Maggi, R.M. McDermott, T. Pütterich, A. Thorman, M. Willensdorfer, null the ASDEX Upgrade Team, null the EUROfusion MST1 Team, null JET Contributors, Schneider, P, Angioni, C, Frassinetti, L, Horvath, L, Maslov, M, Auriemma, F, Cavedon, M, Challis, C, Delabie, E, Dunne, M, Climent, J, Hobirk, J, Kappatou, A, Keeling, D, Kurzan, B, Lennholm, M, Lomanowski, B, Maggi, C, Mcdermott, R, Putterich, T, Thorman, A, Willensdorfer, M, ASDEX Upgrade Team, Max Planck Institute for Plasma Physics, Max Planck Society, EUROfusion MST1 Team, and JET Contributors

Subjects
Nuclear and High Energy Physics, 0103 physical sciences, pedestal stability, 010306 general physics, Condensed Matter Physics, 01 natural sciences, tokamak, heat transport, quasilinear modelling, 010305 fluids & plasmas, isotope effect
Abstract

Experiments in ASDEX Upgrade (AUG) and JET with the ITER-like wall (JET-ILW) are performed to separate the pedestal and core contributions to confinement in H-modes with different main ion masses. A strong isotope mass dependence in the pedestal is found which is enhanced at high gas puffing. This is because the ELM type changes when going from D to H for matched engineering parameters, which is likely due to differences in the inter ELM transport with isotope mass. The pedestal can be matched in H and D plasmas by varying only the triangularity and keeping the engineering parameters relevant for core transport the same. With matched pedestals Astra/TGLF (Sat1geo) core transport simulations predict the experimental profiles equally well for H and D. These core transport simulations show a negligible mass dependence and no gyro-Bohm scaling is observed. However, to match the experimental observations at medium β it is required to take the fast-ion dilution and rotation into account. This is not enough for high β plasmas where for the first time a profile match between H and D plasmas was achieved experimentally. Under these conditions quasilinear modelling with TGLF over predicts the transport in the core of H and D plasmas alike.

Published
2022
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35. Core integrated simulations for the Divertor Tokamak Test facility scenarios towards consistent core-pedestal-SOL modelling

Author

I Casiraghi, P Mantica, R Ambrosino, L Aucone, B Baiocchi, L Balbinot, T Barberis, A Castaldo, M Cavedon, L Frassinetti, P Innocente, F Koechl, S Nowak, P Agostinetti, S Ceccuzzi, L Figini, G Granucci, P Vincenzi, Casiraghi, I, Mantica, P, Ambrosino, R, Aucone, L, Baiocchi, B, Balbinot, L, Barberis, T, Castaldo, A, Cavedon, M, Frassinetti, L, Innocente, P, Koechl, F, Nowak, S, Agostinetti, P, Ceccuzzi, S, Figini, L, Granucci, G, and Vincenzi, P

Subjects
Nuclear Energy and Engineering, integrated modelling, Divertor Tokamak Test facility, DTT, turbulent transport, core-edge-SOL simulations, Condensed Matter Physics, core-edge-SOL simulation
Abstract

Deuterium plasma discharges of the Divertor Tokamak Test facility (DTT) in different operational scenarios have been predicted by a comprehensive first-principle based integrated modelling activity using state-of-art quasi-linear transport models. The results of this work refer to the updated DTT configuration, which includes a device size optimisation (enlargement to R 0 = 2.19 m and a = 0.70 m) and upgrades in the heating systems. The focus of this paper is on the core modelling, but special attention was paid to the consistency with the scrape-off layer parameters required to achieve divertor plasma detachment. The compatibility of these physics-based predicted scenarios with the electromagnetic coil system capabilities was then verified. In addition, first estimates of DTT sawteeth and of DTT edge localised modes were achieved.

Published
2023

36. X-point radiation, its control and an ELM suppressed radiating regime at the ASDEX Upgrade tokamak

Author

F. Reimold, M. Griener, M. Wischmeier, B. Sieglin, O. Kudlacek, Matthias Komm, A. Kallenbach, W. Treutterer, E. Wolfrum, M. Dunne, P. David, S. S. Henderson, D. Brida, M. Bernert, Bruce Lipschultz, R. M. McDermott, M. Cavedon, F. Janky, Olivier Février, EUROfusion MST1 Team, ASDEX Upgrade Team, Max Planck Institute for Plasma Physics, Max Planck Society, Bernert, M, Janky, F, Sieglin, B, Kallenbach, A, Lipschultz, B, Reimold, F, Wischmeier, M, Cavedon, M, David, P, Dunne, M, Griener, M, Kudlacek, O, Mcdermott, R, Treutterer, W, Wolfrum, E, Brida, D, Fevrier, O, Henderson, S, and Komm, M

Subjects
Nuclear and High Energy Physics, x-point radiation, Tokamak, Materials science, asdex upgrade, Radiation, 7. Clean energy, 01 natural sciences, 010305 fluids & plasmas, law.invention, Plasma, ASDEX Upgrade, law, 0103 physical sciences, 010306 general physics, Steady state, power exhaust, Divertor, Mechanics, Fusion power, Condensed Matter Physics, impurity seeding, elm suppression, detachment control, high confinement, detachment, Seeding, Radiator
Abstract

Future fusion reactors require a safe, steady state divertor operation. The required detached operation is, in tokamaks with metal walls, usually achieved by seeding of impurities, such as nitrogen. With strong seeding levels, the dominant radiation is emitted from a small, poloidally localized volume inside the confined region, in the vicinity of the X-point. The location of the radiating volume is observed to vary relative to the X-point depending on seeding and power levels, i.e. depending on the degree of detachment. At the ASDEX Upgrade tokamak, the position of the radiator relative to the X-point can be controlled in real time by a modulation of the nitrogen puff level. At a certain height of the radiator above the X-point, an ELM-suppressed regime is observed with minimal reduction of confinement. While the control of the X-point radiator already allows operation in full detachment at a dissipated power fraction of around 95 %, which is required for a future reactor and was previously never achieved in a controlled way, such an ELM-suppressed regime additionally eliminates the challenge of the transient, intolerably high heat fluxes by ELMs. Both requirements are met in the presented regime while maintaining a high energy confinement at high density.

Published
2021

37. Influence of pedestal radiation on the H–L transition using krypton seeded discharges at ASDEX Upgrade

Author

P. David, M. Bernert, M. Cavedon, G. Harrer, T. Eich, the ASDEX Upgrade Team, ASDEX Upgrade Team, Max Planck Institute for Plasma Physics, Max Planck Society, David, P, Bernert, M, Cavedon, M, Harrer, G, and Eich, T

Subjects
Plasma, Nuclear and High Energy Physics, Condensed Matter Physics
Abstract

Krypton can be a tool to refine and analyse the H–L power threshold in detail, as a proxy for L–H threshold, taking into account radiative losses in the region where the H–L transition takes place and, thus, decouple the power flux over the pedestal top to the one over the separatrix. The commonly used ITPA 2008 L–H threshold scaling does not account for radiation but it is often assumed that it should be compared to the net power crossing the separatrix. Yet, dedicated analyses are still lacking. At ASDEX Upgrade, krypton radiates dominantly at the very edge of the confined plasma (ρ pol between 0.97 and 1.01). Recent results show that L–H and H–L transitions are initiated close to ρ pol = 0.98. As such, the bulk of krypton radiation is between the separatrix and a potential source location for the transition. Scans in krypton seeding level and heating power have been performed to study and compare the influence of the powers radiated from inside the separatrix and the pedestal top on the plasma confinement state. The heating power is compared to the usual L–H power scaling but corrected by either of these two radiations for seeded H–L transitions. The power scaling is shown to remain valid for higher input and radiated powers, up to 3–5 times the non-seeded L–H power threshold of AUG, when the radiation inside the separatrix is subtracted from the input power. Additionally, kinetic and radiation profiles are used to run TRANSP analyses to compare the edge ion heat to past studies from unseeded discharges. Using this physical parameter gives a reference point from a very different parameter range of input and radiated powers, densities and back, instead of forward, transition.

Published
2022

38. Impact of plasma-wall interaction and exhaust on the EU-DEMO design

Author

C. Vorpahl, J. Gerardin, Irena Ivanova-Stanik, Wolfgang Biel, M. Cavedon, Stylianos Varoutis, Mattia Siccinio, M. Firdaouss, C. Bachmann, Volker Hauer, Francesco Maviglia, Fulvio Militello, R. Kembleton, E. Fable, Fabio Subba, G. Federici, F. Janky, Maviglia, F, Siccinio, M, Bachmann, C, Biel, W, Cavedon, M, Fable, E, Federici, G, Firdaouss, M, Gerardin, J, Hauer, V, Ivanova-Stanik, I, Janky, F, Kembleton, R, Militello, F, Subba, F, Varoutis, S, and Vorpahl, C

Subjects
Disruptions, Divertor reattachment, ELMs, EU-DEMO, Limiters, Transients, Nuclear and High Energy Physics, Work (thermodynamics), Materials science, Steady state (electronics), Materials Science (miscellaneous), Nuclear engineering, 01 natural sciences, 010305 fluids & plasmas, Limiter, 0103 physical sciences, ddc:530, 010302 applied physics, Transient, Physics, Divertor, Plasma, Dissipation, lcsh:TK9001-9401, Power (physics), Nuclear Energy and Engineering, Heat flux, lcsh:Nuclear engineering. Atomic power, Disruption, ELM, ddc:624
Abstract

In the present work, the role of plasma facing components protection in driving the EU-DEMO design will be reviewed, focusing on steady-state and, especially, on transients. This work encompasses both the first wall (FW) as well as the divertor. In fact, while the ITER divertor heat removal technology has been adopted, the ITER FW concept has been shown in the past years to be inadequate for EU-DEMO. This is due to the higher foreseen irradiation damage level, which requires structural materials (like Eurofer) able to withstand more than 5 dpa of neutron damage. This solution, however, limits the tolerable steady-state heat flux to ~1 MW/m2, i.e. a factor 3–4 below the ITER specifications. For this reason, poloidally and toroidally discontinuous protection limiters are implemented in EU-DEMO. Their role consists in reducing the heat load on the FW due to charged particles, during steady state and, more importantly, during planned and off-normal plasma transients. Concerning the divertor configuration, EU-DEMO currently assumes an ITER-like, lower single null (LSN) divertor, with seeded impurities for the dissipation of the power. However, this concept has been shown by numerous simulations in the past years to be marginal during steady-state (where a detached divertor is necessary to maintain the heat flux below the technological limit and to avoid excessive erosion) and unable to withstand some relevant transients, such as large ELMs and accidental loss of detachment. Various concepts, deviating from the ITER design, are currently under investigation to mitigate such risks, for example in-vessel coils for strike point sweeping in case of reattachment, as well as alternative divertor configurations. Finally, a broader discussion on the impact of divertor protection on the overall machine design is presented.

Published
2021

39. New assessment of the fast ion energy in ASDEX upgrade H-mode discharges

Author

G. Tardini, M. Weiland, C. Angioni, M. Cavedon, F. Ryter, P.A. Schneider, The ASDEX Upgrade Team, ASDEX Upgrade Team, Max Planck Institute for Plasma Physics, Max Planck Society, Tardini, G, Weiland, M, Angioni, C, Cavedon, M, Ryter, F, and Schneider, P

Subjects
Nuclear and High Energy Physics, Materials science, Nuclear engineering, scaling law, Mode (statistics), Condensed Matter Physics, 01 natural sciences, 7. Clean energy, 010305 fluids & plasmas, H-mode, ASDEX Upgrade, neutral beam injection, confinement, 0103 physical sciences, fast-ion, 010306 general physics, Ion energy
Abstract

Confinement scaling laws such as IPB98(y, 2) are widely used to extrapolate the performance of present tokamaks to next-step devices such as ITER or DEMO. The thermal energy of the plasma (W th), which is used to determine the energy confinement time for most scaling laws, is difficult to measure, due to the sizeable uncertainties in the experimental kinetic profiles. The common approach in the tokamak community is to derive W th as the difference between the measured magnetohydrodynamic (MHD) energy and some simulation-based estimate of the fast ion energy W fi. In H-mode plasmas W fi can be as high as W th, in presence of neutral beam injection (NBI) or ion cyclotron radio frequency heating (ICRF), therefore an accurate assessment of W fi is crucial to have a somewhat reliable H-factor, regardless of the power-scaling of a given scaling law. In this paper we aim at evaluating the current approach to estimate W fi, by comparing its predictions with a wide database of calculations using validated NBI codes. Systematic deviations and trends, as well as statistical scatter are discussed. We use a comprehensive database of AUG H-mode deuterium plasmas, with significant variations of plasma current, NBI power and plasma density. We neglect thereby the fast-ion losses caused by MHD modes and the synergy effect between NBI and ICRF. A new approach is proposed based on the newly developed fast NBI code RABBIT.

Published
2021
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40. Poloidally resolved measurements of the perpendicular propagation velocity of density fluctuations in ASDEX Upgrade L-mode plasmas

Author

K Höfler, T Happel, P Hennequin, U Stroth, M Cavedon, R Dux, R Fischer, R M McDermott, E Poli, C U Schuster, E Wolfrum, the ASDEX Upgrade Team, ASDEX Upgrade Team, Max Planck Institute for Plasma Physics, Max Planck Society, Max-Planck-Institut für Plasmaphysik [Garching] (IPP), 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), Hofler, K, Happel, T, Hennequin, P, Stroth, U, Cavedon, M, Dux, R, Fischer, R, Mcdermott, R, Poli, E, Schuster, C, and Wolfrum, E

Subjects
Tokamak, Drift velocity, 01 natural sciences, 010305 fluids & plasmas, law.invention, symbols.namesake, ASDEX Upgrade, law, Physics::Plasma Physics, [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], 0103 physical sciences, perpendicular velocity, Doppler reflectometry, 010306 general physics, tokamak, Physics, Computer Science::Information Retrieval, Magnetic confinement fusion, Plasma, Condensed Matter Physics, ddc, Magnetic field, Computational physics, plasma flows, Nuclear Energy and Engineering, phase velocity, plasma turbulence, symbols, Phase velocity, Plasma flow, Doppler effect
Abstract

Poloidal asymmetries of the propagation velocity of density fluctuations perpendicular to the magnetic field measured with Doppler reflectometry have been reported in several magnetic confinement plasma devices. Careful analysis of a large variety of different low confinement mode plasma scenarios performed at the ASDEX Upgrade tokamak does not reveal such an asymmetry outside the uncertainties of the evaluation process of the measurement data. The perpendicular velocity is investigated between mid-radius and the plasma edge and follows the poloidal dependence of the E × B drift velocity regardless of the probed turbulence structure size. Compared to measurements of a charge exchange recombination spectroscopy diagnostic this points towards a significantly smaller phase velocity than the E × B drift velocity. The analysis technique is presented in a representative discharge together with a sensitivity study of the impact of density, magneto hydrodynamic equilibrium and diagnostic alignment on the interpretation of the measured Doppler shift using ray tracing and thus on poloidal asymmetries. Three more highly different plasma scenarios with poloidally symmetric velocity profiles are shown.

Published
2021

41. In-out charge exchange measurements and 3D modelling of diagnostic thermal neutrals to study edge poloidal impurity asymmetries

Author

D J Cruz-Zabala, E Viezzer, U Plank, R M McDermott, M Cavedon, E Fable, R Dux, P Cano-Megias, T Pütterich, A Jansen van Vuuren, M Garcia-Munoz, J Garcia Lopez, Cruz-Zabala, D, Viezzer, E, Plank, U, Mcdermott, R, Cavedon, M, Fable, E, Dux, R, Cano-Megias, P, Putterich, T, Van Vuuren, A, Garcia-Munoz, M, Garcia Lopez, J, and ASDEX Upgrade Team, Max Planck Institute for Plasma Physics, Max Planck Society

Subjects
Nuclear Energy and Engineering, impurity, Condensed Matter Physics, asymmetry, CXRS
Abstract

A new method was developed to model the neutral population produced by the gas puff based charge exchange recombination spectroscopy systems at ASDEX Upgrade (AUG). With this method, the edge impurity density on the high field side (HFS) and low field side (LFS) can be obtained without the need to apply a neutral beam injection system. The neutral penetration needed for the calculation of the impurity density is obtained with a new gas puff module implemented in the FIDASIM code. The LFS impurity density profile evaluated with the new gas puff module matches the impurity density calculated with standard beam-based charge exchange diagnostics. Impurity temperature, rotation and density profiles at the HFS and LFS of an AUG H-mode discharge are presented. Edge impurity toroidal and poloidal flows show asymmetric structures. The impurity density asymmetries obtained with the new gas puff module are consistent with the observed flow structure.

Published
2022

42. Corrigendum: A novel method of studying the core boron transport at ASDEX Upgrade (2018 Plasma Phys. and Control. Fusion 60 085011)

Author

A. Kappatou, J Ameres, R. M. McDermott, Pierre Manas, M. Cavedon, R. Dux, C. Angioni, A. Lebschy, R. Ochoukov, C. Bruhn, V. Bobkov, and ASDEX Upgrade Team, Max Planck Institute for Plasma Physics, Max Planck Society

Subjects
Fusion, Tokamak, Materials science, Nuclear engineering, Plasma, Condensed Matter Physics, 01 natural sciences, 010305 fluids & plasmas, law.invention, Core (optical fiber), Boron transport, Nuclear Energy and Engineering, ASDEX Upgrade, law, 0103 physical sciences, 010306 general physics
Published
2020
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43. H-mode power threshold studies in mixed ion species plasmas at ASDEX Upgrade

Author

R. Fischer, P. A. Schneider, A. Kappatou, T. Happel, C. Angioni, U. Plank, G. D. Conway, G. Tardini, Th. Pütterich, M. Weiland, R. M. McDermott, M. Cavedon, ASDEX Upgrade Team, Max Planck Institute for Plasma Physics, Max Planck Society, Plank, U, Putterich, T, Angioni, C, Cavedon, M, Conway, G, Fischer, R, Happel, T, Kappatou, A, Mcdermott, R, Schneider, P, Tardini, G, and Weiland, M

Subjects
Nuclear and High Energy Physics, Materials science, Hydrogen, Doping, chemistry.chemical_element, Plasma, Condensed Matter Physics, L-H transition, 01 natural sciences, 7. Clean energy, isotope mix, 010305 fluids & plasmas, Ion, ITER operation, Heat flux, chemistry, Deuterium, ASDEX Upgrade, Physics::Plasma Physics, 0103 physical sciences, Physics::Atomic Physics, Atomic physics, 010306 general physics, edge ion heat flux, Helium
Abstract

Understanding the dependence of the H-mode power threshold, PLH on the main ion composition is crucial for H-mode operation in ITER. In this work, H-mode power threshold studies conducted at ASDEX Upgrade are presented. These were performed in hydrogen plasmas with helium doping and in mixed hydrogen-deuterium plasmas. PLH stays constant on the level of pure hydrogen in hydrogen plasmas with helium doping up to cHe = 20%. Power balance calculations with the transport code ASTRA show that the edge ion heat flux at the L-H transition is independent of helium concentration and applied auxiliary heating, supporting that a critical edge ion heat flux is needed to enter H-mode. A non-linear dependence of PLH on the relative hydrogen content is found. PLH and the edge ion heat flux are constant at the level of pure deuterium for between 0 and 0.5 and constant on the level of pure hydrogen for between 0.8 and 1.

Published
2020
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44. DEMO physics challenges beyond ITER

Author

Francesco Maviglia, F. Palermo, H. Zohm, Wolfgang Biel, E. Fable, Fabio Subba, Mattia Siccinio, Olivier Sauter, M. Cavedon, G. Federici, F. Janky, J. Morris, H. Lux, Siccinio, M., Biel, W., Cavedon, M., Fable, E., Federici, G., Janky, F., Lux, H., Maviglia, F., Morris, J., Palermo, F., Sauter, O., Subba, F., Zohm, H., Siccinio, M, Biel, W, Cavedon, M, Fable, E, Federici, G, Janky, F, Lux, H, Maviglia, F, Morris, J, Palermo, F, Sauter, O, Subba, F, and Zohm, H

Subjects
Tokamak, Nuclear engineering, design, fusion power-plants, EU-DEMO, ITER, Plasma scenario, ELM-free regimes, ELMy H-mode, 7. Clean energy, 01 natural sciences, 010305 fluids & plasmas, law.invention, law, 0103 physical sciences, divertor, General Materials Science, ddc:530, 010306 general physics, Baseline (configuration management), Civil and Structural Engineering, model, business.industry, Mechanical Engineering, Divertor, Plasma, Power (physics), Nuclear Energy and Engineering, 13. Climate action, Auxiliary power unit, systems code, ELM-free regime, Transient (oscillation), Electricity, business
Abstract

For electricity producing tokamak fusion reactors like EU-DEMO, it is prudent to choose a plasma scenario close to the ITER baseline, where the largest amount of experimental evidence is available. Nevertheless, there are some aspects in which ITER and EU-DEMO have to differ, as the simple exercise of up-scaling from ITER to a larger device is constrained both by physical nonlinearities and by technological limits. In this work, relevant differences between ITER and the current EU-DEMO baseline in terms of plasma scenario are discussed. Firstly, EU-DEMO is assumed to operate with a very large amount of radiative power originating both from the scrape-off layer and, markedly, from the core. This radiation level is obtained by means of seeded impurities, whose presence significantly affects many aspects of the scenario itself, especially in terms of transient control. Secondly, because of the need of breeding tritium, the EU-DEMO wall is less robust than the ITER one. This implies that every off-normal interruption of the plasma discharge, for example in presence of a divertor reattachment, cannot rely on fast-shutdown procedures finally triggering a loss of plasma control at high current, but other strategies need to be developed. Thirdly, the ITER method for the control of the so-called sawteeth (ST) has been shown to be too expensive in terms of auxiliary power requirements, thus other solutions have to be explored. Finally, the problem of actively mitigating, or suppressing, the Edge Localised Modes (ELMs) has recently increased the interest on naturally ELM-free regimes (like QH-mode, I-mode, and also negative triangularity) for EU-DEMO, thus increasing the needs for ELM mitigation or suppression with respect to the approach adopted in ITER.

Published
2020

45. Linearized spectrum correlation analysis for thermal helium beam diagnostics

Author

Shinichiro Kado, T. Nishizawa, G. Grenfell, R. Dux, M. Cavedon, M. Griener, D. Wendler, P. Manz, ASDEX Upgrade Team, Max Planck Institute for Plasma Physics, Max Planck Society, Nishizawa, T, Griener, M, Dux, R, Grenfell, G, Wendler, D, Kado, S, Manz, P, and Cavedon, M

Subjects
Physics, Electron density, Tokamak, Plasma parameters, chemistry.chemical_element, 7. Clean energy, 01 natural sciences, Noise (electronics), ddc, 010305 fluids & plasmas, law.invention, Computational physics, chemistry, ASDEX Upgrade, law, 0103 physical sciences, Electron temperature, 010306 general physics, Instrumentation, plasma, Helium, Beam (structure)
Abstract

We introduce a new correlation analysis technique for thermal helium beam (THB) diagnostics. Instead of directly evaluating line ratios from fluctuating time series, we apply arithmetic operations to all available He I lines and construct time series with desired dependencies on the plasma parameters. By cross-correlating those quantities and by evaluating ensemble averages, uncorrelated noise contributions can be removed. Through the synthetic data analysis, we demonstrate that the proposed analysis technique is capable of providing the power spectral densities of meaningful plasma parameters, such as the electron density and the electron temperature, even under low-photon-count conditions. In addition, we have applied this analysis technique to the experimental THB data obtained at the ASDEX Upgrade tokamak and successfully resolved the electron density and temperature fluctuations up to 90 kHz in a reactor relevant high power scenario.

Published
2021

46. 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

47. Dynamics of ideal modes and subsequent ELM crashes in 3D tokamak geometry from external magnetic perturbations

Author

F. Mink, E. Strumberger, W. Suttrop, M. Cavedon, Chris Hegna, M. Willensdorfer, M. Griener, A. Kirk, Matthias Hoelzl, F. Orain, R. Fischer, E. Seliunin, J. Galdon-Quiroga, T. B. Cote, H. Zohm, M. G. Dunne, N. Leuthold, S. S. Denk, M. Maraschek, Nengchao Wang, C. J. Ham, D. A. Ryan, Willensdorfer, M, Cote, T, Griener, M, Ryan, D, Strumberger, E, Suttrop, W, Wang, N, Cavedon, M, Denk, S, Dunne, M, Fischer, R, Galdon-Quiroga, J, Ham, C, Hegna, C, Hoelzl, M, Kirk, A, Maraschek, M, Mink, F, Leuthold, N, Orain, F, Seliunin, E, Zohm, H, ASDEX Upgrade Team, Max Planck Institute for Plasma Physics, Max Planck Society, and MST1 Team

Subjects
Physics, Tokamak, Ideal (set theory), ideal MHD, Dynamics (mechanics), RMP, Mechanics, Condensed Matter Physics, 01 natural sciences, ddc, 010305 fluids & plasmas, law.invention, Nuclear Energy and Engineering, law, 0103 physical sciences, 010306 general physics, 3D tokamak
Abstract

The impact of three-dimensional (3D) tokamak geometry from external magnetic perturbations on edge instabilities has been examined in high confinement mode plasmas with edge localised modes (ELMs) in ASDEX Upgrade. The 3D geometry has been probed using rigidly rotating MP fields. The measured distortions of the plasma boundary are compared to single-fluid ideal magnetohydrodynamic (MHD) equilibria using VMEC and MARS-F applying ideal and resistive MHD, whereas VMEC uses only ideal MHD. Both codes accurately reproduce the measured radial displacements of the edge density and temperature profiles in amplitude, toroidal phase and their dependence on the applied poloidal mode spectrum. The induced 3D geometry distorts the local magnetic shear, which locally reduces the stabilising effect from field-line bending at certain most unstable field lines. Around these field lines, we observe additional stable ideal MHD modes with clear ballooning structure in-between ELMs. After their immediate appearance, they saturate and then grow on timescales of the pedestal pressure recovery. The subsequent ELMs show strongly localised magnetic perturbations of the initial crash and accompanied energetic electrons around the same most unstable field lines. These are strong signatures that filaments at the ELM onset preferentially erupt on these most unstable ('bad') field lines with their unfavourable 3D geometry where preceding ballooning modes are observed.

Published
2019

48. On the ion and electron temperature recovery after the ELM-crash at ASDEX upgrade

Author

T. Pütterich, A. F. Mink, R. Dux, G. F. Harrer, R. Fischer, U. Stroth, E. Viezzer, E. Fable, M. Willensdorfer, M. G. Dunne, M. Cavedon, Florian Laggner, U. Plank, E. Wolfrum, Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, ASDEX Upgrade Team, Max Planck Institute for Plasma Physics, Max Planck Society, Cavedon, M, Dux, R, Putterich, T, Viezzer, E, Wolfrum, E, Dunne, M, Fable, E, Fischer, R, Harrer, G, Laggner, F, Mink, A, Plank, U, Stroth, U, Willensdorfer, M, and Upgrade Team, A

Subjects
Nuclear and High Energy Physics, Materials science, Materials Science (miscellaneous), Ion temperature, Electron, 01 natural sciences, 7. Clean energy, Neutral ionization, 010305 fluids & plasmas, Ion, ASDEX Upgrade, Physics::Plasma Physics, Ionization, 0103 physical sciences, Heat exchanger, Radiative transfer, Fast Charge Exchange, Saturation (magnetic), 010302 applied physics, ETG, lcsh:TK9001-9401, Nuclear Energy and Engineering, lcsh:Nuclear engineering. Atomic power, Electron temperature, ELM, Atomic physics
Abstract

The access to fast measurements, i.e. Δt ≈ 100 µs, of the ions and the electrons during an entire edge localized cycle (ELM) reveals asymmetries in the recovery of the maximum edge gradients. Different magnetic fluctuations are found to correlate with the saturation of the edge ion temperature (Ti), electrons temperature (Te) and density (ne) gradients. In particular, while ∇Ti and ∇ne clamp roughly 3.0 ms after the ELM-crash together with the onset of mid-frequency (f ≲ 50 kHz) magnetic fluctuations, ∇Te recovers to the pre-ELM conditions only after 7.0 ms and saturates with the appearance of high frequency fluctuations (f ≈ 200 kHz). The effect of electron temperature gradient modes (ETGs) and of energy losses induced by ionization of neutrals are discussed as possible reasons for the delayed recovery of ∇Te. The onset and the suppression of ETGs qualitatively follow the requirements of an increased electron heat transport. However, gyro-kinetic simulations are necessary to quantify the impact of ETGs. On the other hand, the impact of the neutral ionization during the density build-up as an electron energy loss channel is measured to be small compared to the total electron energy. The dominant terms in the electron energy balance are instead the radiative power and the ion-electron heat exchange. Keywords: ELM, Ion temperature, ETG, Neutral ionization, Fast Charge Exchange

Published
2019
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49. Feasibility study for an edge main ion charge exchange recombination spectroscopy system at ASDEX Upgrade

Author

R. Chacartegui, M. Cavedon, A. Jansen van Vuuren, R. Dux, D. J. Cruz-Zabala, Benedikt Geiger, M. Garcia-Munoz, E. Viezzer, P. Cano-Megias, Cano-Megias, P, Viezzer, E, van Vuuren, A, Cavedon, M, Cruz-Zabala, D, Dux, R, Geiger, B, Garcia-Munoz, M, Chacartegui, R, Universidad de Sevilla. Departamento de Ingeniería Energética, Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, Ministerio de Ciencia, Innovación y Universidades (MICINN). España, European Union (UE). H2020, Ministerio de Economía y Competitividad (MINECO). España, and EUROfusion Consortium

Subjects
Tokamak, Plasma parameters, Data processing method, 01 natural sciences, Spectral line, 030218 nuclear medicine & medical imaging, Ion, law.invention, 03 medical and health sciences, 0302 clinical medicine, Plasma diagnostics - charged-particle spectroscopy, ASDEX Upgrade, Physics::Plasma Physics, law, 0103 physical sciences, Radiative transfer, Emission spectrum, Spectroscopy, Instrumentation, Mathematical Physics, Physics, 010308 nuclear & particles physics, Computational physics, Data processing methods, Analysis and statistical methods, Analysis and statistical method
Abstract

A feasibility study for a new edge main ion charge exchange recombination spectroscopy (CXRS) system at the ASDEX Upgrade tokamak has been carried out. This diagnostic uses the new edge fast-ion Dα (FIDA) spectrometers and the optical heads of the existing edge CXRS systems. Standard CXRS resolved temperature and rotation profiles rely on the observation of impurity emission lines. The complexity of the photoemission processes and the fact that the measured ions represent the majority bulk plasma ions (here deuterium) make the interpretation of the main ion spectra in comparison more challenging. At the plasma edge, the diagnostic capabilities in terms of temporal and spatial resolution are extremely demanding. The difficulties in the interpretation of the main ion spectra are overcome by comprehensive fitting and forward modelling of the beam halo (which introduces a major challenge) using a collisional radiative model, as described in [1]. In this work, the diagnostic set up and the sensitivity of the main ion spectra to changes in plasma parameters have been characterized. The tools and techniques necessary for a correct interpretation of the spectra are also discussed. In addition to the halo effect, corrections due to atomic physics effects which could affect the splitting and broadening of the spectral Dα line and lead to misinterpretation of the spectra are evaluated. The first measurements of the edge main ion diagnostic are also presented. Spanish Ministry of Science, Innovation and Universities (grant FPU17/06273) H2020 Marie-Sklodowska Curie programme (Grant No. 708257) Spanish Ministry of Economy and Competitiveness (Grant No. FJCI-201422139) EUROfusion Consortium grant agreement No 633053

Published
2019

50. Link between divertor conditions and high-field-side/low-field-side midplane density profiles in H-mode plasmas at ASDEX Upgrade

Author

J. M. Santos, E. Wolfrum, F. Reimold, E. Seliunin, A. Silva, José Vicente, M. Bernert, Carlos A. Silva, L. Guimarais, T. Reichbauer, A. Drenik, U. Stroth, M. Cavedon, D. Brida, G. D. Conway, L. Gil, EUROfusion Mst Team, Guimarais, L, Silva, C, Bernert, M, Brida, D, Cavedon, M, Conway, G, Drenik, A, Gil, L, Reichbauer, T, Reimold, F, Santos, J, Seliunin, E, Silva, A, Stroth, U, Vicente, J, Wolfrum, E, ASDEX Upgrade Team, Max Planck Institute for Plasma Physics, Max Planck Society, and EUROfusion MST1 Team

Subjects
Nuclear and High Energy Physics, Materials science, Field (physics), Divertor, Mode (statistics), Plasma, Condensed Matter Physics, 01 natural sciences, 010305 fluids & plasmas, Computational physics, ASDEX Upgrade, 0103 physical sciences, High field, 010306 general physics, plasma
Abstract

The connection between midplane and divertor conditions is studied on ASDEX Upgrade (AUG) for H-mode scenarios. H-mode discharges with variations in fuelling, heating power and impurity seeding are analysed, enabling to disentangle their impact on the evolution of midplane density profiles. The O-mode reflectometer installed on AUG provides unique insights on the midplane density profiles thanks to the ability to measure simultaneously at the high-field-side (HFS) and the low-field-side (LFS). At the inner divertor, with the onset of detachment, a region of high density is formed (HFS high density front, HFSHD) that expands into the HFS midplane, leading to strong poloidal asymmetries in the main chamber scrape-off layer (SOL) density. A good agreement is observed between the evolution of the density profiles at the midplane and that of the divertor volume density confirming the strong influence of divertor conditions on the midplane density profiles at the HFS. Our results confirm the existence of a relationship between plasma confinement, the shift in the midplane LFS density profile and the presence of the HFSHD with respect to changes in seeding and fuelling. It is established that the separatrix density at the LFS is better correlated with the neutral pressure at the outer target while the HFS SOL density follows the neutral pressure at the inner divertor. A comprehensive characterisation of the edge-localised mode (ELM) evolution at the midplane and divertor is performed demonstrating that also during the ELM cycle the divertor conditions have a strong effect on the SOL density at the midplane. The most striking result is the observation of a HFSHD at the HFS midplane just after the ELM crash associated with strong inner divertor detachment.

Published
2019
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