Overview of the ASDEX Upgrade results

T. Pütterich, F. Albrecht, E. Alessi, S. An, C. Angioni, F. Antlitz, N. Arden, V. Artigues, M. Astrain, M. Balden, A. Banon Navarro, A. Bergmann, M. Bergmann, M. Bernert, A. Biancalani, R. Bielajew, M. Biasizzo, R. Bilato, G. Birkenmeier, T. Blanken, V. Bobkov, A. Bock, T. Bolzonella, A. Bortolon, B. Böswirth, A. Bottino, H. van den Brand, M. Brenzke, S. Brezinsek, D. Brida, D. Brioschi, F. Brochard, J. Buchanan, A. Buhler, A. Burckhart, Y. Camenen, B. Cannas, P. Cano Megías, J.A. Capitan Garcia, M. Carr, C. Castaldo, A. Castillo Castillo, A. Cathey, M. Cavedon, C. Cazzaniga, C. Challis, A. Chankin, A. Chomiczewska, C. Cianfarani, F. Clairet, S. Coda, J.W. Coenen, G. Conway, S. Costea, D. Coster, T. Cote, D. Cretu, G. Croci, D.J. Cruz Zabala, G. Cseh, I. Cziegler, O. D’Arcangelo, A. Dal Molin, P. David, C. Drobny, M. de Baar, P. de Marné, R. Delogu, P. Denner, A. Di Siena, 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, R. Fischer, O. Ford, L. Frassinetti, M. Fröschle, G. Fuchert, J.C. Fuchs, M. Fulici, H. Fünfgelder, S. Futatani, K. Galazka, J. Galdon-Quiroga, D. Gallart Escolá, Y. Gao, S. Garavaglia, J. Garcia-Dominguez, M. Garcia Muñoz, M. Gehring, B. Geiger, L. Giannone, S. Gibson, L. Gil, E. Giovannozzi, O. Girka, T. Gleiter, M. Gobbin, I. Gomez Ortiz, 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, S. Günter, D. Hachmeister, A.H. Hakola, C. Ham, T. Happel, N. den Harder, G. Harrer, J. Harrison, V. Hartmann, T. Hayward-Schneider, B. Heinemann, P. Heinrich, T. Hellsten, S. Henderson, P. Hennequin, C. Herkommer, A. Herrmann, M. Herschel, S. Heuraux, E. Heyn, J. Hidalgo-Salaverri, F. Hindenlang, J. Hobirk, I. Hofer-Maksymiw, K. Höfler, L. Hollendonner, J.H. Holm, M. Hölzl, C. Hopf, S. Hörmann, L. Horvath, T. Höschen, A. Houben, A. Hubbard, A. Huber, K. Hunger, V. Igochine, M. Iliasova, J. Illerhaus, K. Insulander Björk, C. Ionita-Schrittwieser, S. Irmer, I. Ivanova-Stanik, S. Jachmich, W. Jacob, A. Jansen van Vuuren, F. Jaulmes, F. Jenko, T. Jensen, M. Jimenez-Comez, A. Kallenbach, J. Kalis, M. Kantor, A. Kappatou, J. Karhunen, C.-P. Käsemann, S. Kasilov, Y. Kazakov, A. Kendl, R. Kermenov, W. Kernbichler, E. Khilkevitch, M. Kircher, A. Kirk, S. Kjer Hansen, F. Klossek, G. Kocsis, M. Komm, M. Kong, A. Krämer-Flecken, M. Krause, A. Kreuzeder, K. Krieger, O. Kudlacek, D. Kulla, B. Kurzan, B. Labit, F. Laggner, A. Lahtinen, P. Lainer, P.T. Lang, P. Lauber, M. Lehnen, E. Lerche, N. Leuthold, L. Li, Y.-C. Liang, J. Likonen, H. Lindl, B. Lipschultz, Y. Liu, G. Lo-Cascio, Z. Lu, T. Luda di Cortemiglia, N.C. Luhmann, T. Lunt, A. Lyssoivan, J. Madsen, H. Maier, M. Maierbeck, J. Mailloux, R. Maingi, S. Makarov, E. Maljaars, V. Maquet, A. Mancini, A. Manhard, P. Mantica, M. Mantsinen, P. Manz, M. Maraschek, C. Marchetto, M. Markl, L. Marrelli, P. Martin, M. Mayer, M.-L. Mayoral, P.J. McCarthy, R. McDermott, K. McKay, R. Merkel, A. Merle, H. Meyer, D. Milanesio, V. Mitterauer, A. Moreau, V. Naulin, R. Nazikian, R.D. Nem, R. Neu, A. Nischler, A.H. Nielsen, S.K. Nielsen, M. Nocente, R. Nocentini, R. Novak, S. Nowak, R. Ochoukov, J. Olsen, P. Oyola, A. Orduna Martinez, O. Pan, G. Papp, I. Paradela Perez, A. Patel, A. Pau, G. Pautasso, C. Paz-Soldan, M. Peglau, E. Peluso, J. Perez Gonzalez, P. Petersson, J. Pfennig, C. Piron, L. Piron, B. Plaum, B. Plöckl, G. Pokol, E. Poli, L. Porte, J. Puchmayr, T. Pütterich, L. Radovanovic, M. Ramisch, J. Rasmussen, G. Ratta, S. Ratynskaia, G. Raupp, A. Redl, D. Réfy, M. Reich, D. Reiser, M. Reisner, D. Reiter, 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. Salerno, M. Salewski, A. Salmi, O. Samoylov, L. Sanchis Sanchez, J. Santos, S. Sasidharan, O. Sauter, G. Schall, J. Schellpfeffer, A. Schlüter, J. Scholte, K. Schmid, O. Schmitz, P.A. Schneider, R. Schramm, R. Schrittwieser, M. Schubert, T. Schwarz-Selinger, J. Schweinzer, O. Seibold-Benjak, A. Shalpegin, S. Sharapov, F. Sheffield, U. Sheikh, A. Shevelev, G. Sias, B. Sieben, M. Siccinio, B. Sieglin, A. Sigalov, A. Silva, C. Silva, D. Silvagni, J. Simpson, S. Sipilä, A. Snicker, E. Solano, F. Solfronk, C. Sommariva, C. Sozzi, M. Spacek, G. Spizzo, M. Spolaore, R. Stadler, F. Stefanelli, B. Stefanoska, A. Stegmeir, M. Stejner, D. Stieglitz, J. Stobbs, J. Stober, U. Stroth, E. Strumberger, R. Stucchi, G. Suarez Lopez, A. Sulimro, W. Suttrop, T. Szepesi, M. Szücs, T. Tala, W. Tang, G. Tardini, M. Tardocchi, D. Terranova, M. Teschke, E. Thorén, R. Takacs, D. Told, W. Treutterer, G. Trevisan, M. Tripský, P. Ulbl, M. Usoltseva, M. Valisa, M. Valovic, M. Van Zeeland, S. Van Mulders, F. Vannini, B. Vanovac, T. Verdier, G. Verdoolaege, N. Vianello, J. Vicente, T. Vierle, E. Viezzer, I. Voitsekhovitch, J.-C. Volz, 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, F. Zahn, I. Zammuto, T. Zehetbauer, H. Zhang, W. Zhang, W. Zholobenko, M. Zilker, C.F.B. Zimmermann, A. Zito, H. Zohm, S. Zoletnik

2026 · Nuclear Fusion · vol. 66 · no. 11 · pp. 116002 · IOP Publishing · 10.1088/1741-4326/ae61c8

Abstract

Abstract After a 26-month vent ASDEX Upgrade (AUG) went back in operation with a newly designed upper W-divertor suitable for alternative divertor configurations (featuring in-vessel coils and cryo-pump). Parameter scans and an extensive set of measurements were obtained and their interpretation is ongoing. Prompted by the ITER wall change, dedicated experiments on non-boronized plasma startup were contrasted to that employing asymmetric and more symmetric boronizations. The asymmetric boronization proved to be as beneficial as the more symmetric one, which is in contrast to previous model calculations assuming perfect sticking of boron (measurements suggest sticking ≈ 0.3). In the startup phase also the impurity influxes at the outboard limiters were investigated contrasting the unboronized case featuring cold edges (low- Z radiation) to the boronized case, in which the lifetime of the boron layers could be estimated. Pedestal stability investigations revealed that the quasi-continuous exhaust (QCE) regime is obtained when ballooning modes are active in the vicinity of the separatrix and the global peeling-ballooning stability is high enough. Thus, at high enough shaping and high gas flux both can be achieved and QCE is a consequence. The closely related enhanced D-alpha (EDA) mode is not clearly distinguishable from QCE, e.g. the quasi-coherent mode characteristic for EDA also shows up in QCE. In QCE the impurity transport is behaving benign as could be measured for Ne with a novel analysis method making use of a comprehensive set of CXRS measurements. For high radiative fractions the regime of the X-point radiator (XPR) is accessible at AUG and the understanding of its access conditions and behaviour is further developed. Due to the localized radiative cooling at the X-point the XPR can be well diagnosed and thus controlled. For negative triangularity shapes, further experiments at increased shaping resulted in strongly heated L-mode plasmas avoiding ELMs. Two integrated modelling approaches towards ITER suggested that core W-accumulation will be no issue for ITER and that the fusion yield in ITER may be Q = 12 (i.e. ITPA20-IL scaling is too pessimistic). Further, investigations of the ITER ramp-down in AUG provide insights into maintaining position control. Various aspects of shattered pellet injection were investigated in AUG and one of the results show that with increasing Ne fraction the radiation during the current quench increases and the current decay becomes faster.

@article{P_tterich_2026,
 title={Overview of the ASDEX Upgrade results},
 volume={66},
 ISSN={1741-4326},
 url={http://dx.doi.org/10.1088/1741-4326/ae61c8},
 DOI={10.1088/1741-4326/ae61c8},
 number={11},
 journal={Nuclear Fusion},
 publisher={IOP Publishing},
 author={Pütterich, T. and Albrecht, F. and Alessi, E. and An, S. and Angioni, C. and Antlitz, F. and Arden, N. and Artigues, V. and Astrain, M. and Balden, M. and Banon Navarro, A. and Bergmann, A. and Bergmann, M. and Bernert, M. and Biancalani, A. and Bielajew, R. and Biasizzo, M. and Bilato, R. and Birkenmeier, G. and Blanken, T. and Bobkov, V. and Bock, A. and Bolzonella, T. and Bortolon, A. and Böswirth, B. and Bottino, A. and van den Brand, H. and Brenzke, M. and Brezinsek, S. and Brida, D. and Brioschi, D. and Brochard, F. and Buchanan, J. and Buhler, A. and Burckhart, A. and Camenen, Y. and Cannas, B. and Cano Megías, P. and Capitan Garcia, J.A. and Carr, M. and Castaldo, C. and Castillo Castillo, A. and Cathey, A. and Cavedon, M. and Cazzaniga, C. and Challis, C. and Chankin, A. and Chomiczewska, A. and Cianfarani, C. and Clairet, F. and Coda, S. and Coenen, J.W. and Conway, G. and Costea, S. and Coster, D. and Cote, T. and Cretu, D. and Croci, G. and Cruz Zabala, D.J. and Cseh, G. and Cziegler, I. and D’Arcangelo, O. and Dal Molin, A. and David, P. and Drobny, C. and de Baar, M. and de Marné, P. and Delogu, R. and Denner, P. and Di Siena, A. and Dominguez Palacios Durán, J.J. and Dunai, D. and Dreval, M. and Dunne, M. and Duval, B.P. and Dux, R. and Eich, T. and Elgeti, S. and Encheva, A. and Esposito, B. and Fable, E. and Faitsch, M. and Fajardo Jimenez, D. and Fantz, U. and Farnik, M. and Faugel, H. and Felici, F. and Ficker, O. and Fischer, R. and Ford, O. and Frassinetti, L. and Fröschle, M. and Fuchert, G. and Fuchs, J.C. and Fulici, M. and Fünfgelder, H. and Futatani, S. and Galazka, K. and Galdon-Quiroga, J. and Gallart Escolá, D. and Gao, Y. and Garavaglia, S. and Garcia-Dominguez, J. and Garcia Muñoz, M. and Gehring, M. and Geiger, B. and Giannone, L. and Gibson, S. and Gil, L. and Giovannozzi, E. and Girka, O. and Gleiter, T. and Gobbin, M. and Gomez Ortiz, I. and Gonzalez, J.C. and Gonzalez Martin, J. and Goodman, T. and Gorini, G. and Görler, T. and Gradic, D. and Granucci, G. and Gräter, A. and Grenfell, G. and Greuner, H. and Griener, M. and Groth, M. and Grover, O. and Gude, A. and Günter, S. and Hachmeister, D. and Hakola, A.H. and Ham, C. and Happel, T. and den Harder, N. and Harrer, G. and Harrison, J. and Hartmann, V. and Hayward-Schneider, T. and Heinemann, B. and Heinrich, P. and Hellsten, T. and Henderson, S. and Hennequin, P. and Herkommer, C. and Herrmann, A. and Herschel, M. and Heuraux, S. and Heyn, E. and Hidalgo-Salaverri, J. and Hindenlang, F. and Hobirk, J. and Hofer-Maksymiw, I. and Höfler, K. and Hollendonner, L. and Holm, J.H. and Hölzl, M. and Hopf, C. and Hörmann, S. and Horvath, L. and Höschen, T. and Houben, A. and Hubbard, A. and Huber, A. and Hunger, K. and Igochine, V. and Iliasova, M. and Illerhaus, J. and Insulander Björk, K. and Ionita-Schrittwieser, C. and Irmer, S. and Ivanova-Stanik, I. and Jachmich, S. and Jacob, W. and Jansen van Vuuren, A. and Jaulmes, F. and Jenko, F. and Jensen, T. and Jimenez-Comez, M. and Kallenbach, A. and Kalis, J. and Kantor, M. and Kappatou, A. and Karhunen, J. and Käsemann, C.-P. and Kasilov, S. and Kazakov, Y. and Kendl, A. and Kermenov, R. and Kernbichler, W. and Khilkevitch, E. and Kircher, M. and Kirk, A. and Kjer Hansen, S. and Klossek, F. and Kocsis, G. and Komm, M. and Kong, M. and Krämer-Flecken, A. and Krause, M. and Kreuzeder, A. and Krieger, K. and Kudlacek, O. and Kulla, D. and Kurzan, B. and Labit, B. and Laggner, F. and Lahtinen, A. and Lainer, P. and Lang, P.T. and Lauber, P. and Lehnen, M. and Lerche, E. and Leuthold, N. and Li, L. and Liang, Y.-C. and Likonen, J. and Lindl, H. and Lipschultz, B. and Liu, Y. and Lo-Cascio, G. and Lu, Z. and Luda di Cortemiglia, T. and Luhmann, N.C. and Lunt, T. and Lyssoivan, A. and Madsen, J. and Maier, H. and Maierbeck, M. and Mailloux, J. and Maingi, R. and Makarov, S. and Maljaars, E. and Maquet, V. and Mancini, A. and Manhard, A. and Mantica, P. and Mantsinen, M. and Manz, P. and Maraschek, M. and Marchetto, C. and Markl, M. and Marrelli, L. and Martin, P. and Mayer, M. and Mayoral, M.-L. and McCarthy, P.J. and McDermott, R. and McKay, K. and Merkel, R. and Merle, A. and Meyer, H. and Milanesio, D. and Mitterauer, V. and Moreau, A. and Naulin, V. and Nazikian, R. and Nem, R.D. and Neu, R. and Nischler, A. and Nielsen, A.H. and Nielsen, S.K. and Nocente, M. and Nocentini, R. and Novak, R. and Nowak, S. and Ochoukov, R. and Olsen, J. and Oyola, P. and Orduna Martinez, A. and Pan, O. and Papp, G. and Paradela Perez, I. and Patel, A. and Pau, A. and Pautasso, G. and Paz-Soldan, C. and Peglau, M. and Peluso, E. and Perez Gonzalez, J. and Petersson, P. and Pfennig, J. and Piron, C. and Piron, L. and Plaum, B. and Plöckl, B. and Pokol, G. and Poli, E. and Porte, L. and Puchmayr, J. and Pütterich, T. and Radovanovic, L. and Ramisch, M. and Rasmussen, J. and Ratta, G. and Ratynskaia, S. and Raupp, G. and Redl, A. and Réfy, D. and Reich, M. and Reiser, D. and Reisner, M. and Reiter, D. and Ricci, D. and Riedl, R. and Riesch, J. and Rivero Rodriguez, J.F. and Rocchi, G. and Rodriguez-Fernandez, P. and Rohde, V. and Ronchi, G. and Rott, M. and Rubel, M. and Ryan, D.A. and Ryter, F. and Saarelma, S. and Salerno, M. and Salewski, M. and Salmi, A. and Samoylov, O. and Sanchis Sanchez, L. and Santos, J. and Sasidharan, S. and Sauter, O. and Schall, G. and Schellpfeffer, J. and Schlüter, A. and Scholte, J. and Schmid, K. and Schmitz, O. and Schneider, P.A. and Schramm, R. and Schrittwieser, R. and Schubert, M. and Schwarz-Selinger, T. and Schweinzer, J. and Seibold-Benjak, O. and Shalpegin, A. and Sharapov, S. and Sheffield, F. and Sheikh, U. and Shevelev, A. and Sias, G. and Sieben, B. and Siccinio, M. and Sieglin, B. and Sigalov, A. and Silva, A. and Silva, C. and Silvagni, D. and Simpson, J. and Sipilä, S. and Snicker, A. and Solano, E. and Solfronk, F. and Sommariva, C. and Sozzi, C. and Spacek, M. and Spizzo, G. and Spolaore, M. and Stadler, R. and Stefanelli, F. and Stefanoska, B. and Stegmeir, A. and Stejner, M. and Stieglitz, D. and Stobbs, J. and Stober, J. and Stroth, U. and Strumberger, E. and Stucchi, R. and Suarez Lopez, G. and Sulimro, A. and Suttrop, W. and Szepesi, T. and Szücs, M. and Tala, T. and Tang, W. and Tardini, G. and Tardocchi, M. and Terranova, D. and Teschke, M. and Thorén, E. and Takacs, R. and Told, D. and Treutterer, W. and Trevisan, G. and Tripský, M. and Ulbl, P. and Usoltseva, M. and Valisa, M. and Valovic, M. and Van Zeeland, M. and Van Mulders, S. and Vannini, F. and Vanovac, B. and Verdier, T. and Verdoolaege, G. and Vianello, N. and Vicente, J. and Vierle, T. and Viezzer, E. and Voitsekhovitch, I. and Volz, J.-C. and von Toussaint, U. and Wagner, D. and Wang, X. and Weiland, M. and Wendler, D. and White, A.E. and Willensdorfer, M. and Wiringer, B. and Wischmeier, M. and Wolf, R. and Wolfrum, E. and Yang, Q. and Yoo, C. and Yu, Q. and Zagórski, R. and Zahn, F. and Zammuto, I. and Zehetbauer, T. and Zhang, H. and Zhang, W. and Zholobenko, W. and Zilker, M. and Zimmermann, C.F.B. and Zito, A. and Zohm, H. and Zoletnik, S.},
 year={2026},
 month=May,
 pages={116002} }