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42 results on '"H. Kollotzek"'

1. Overview of ASDEX Upgrade results—development of integrated operating scenarios for ITER

Author

F. Serra, R. Pugno, S. Klose, A. Herrmann, B. Kurzan, K. Mank, R. Narayanan, Garrard Conway, E. Würsching, O. Gehre, Q. Yu, P. Merkel, U. Seidel, R. Kochergov, T. Eich, K. Krieger, A. Bergmann, M. G. Pacco-Düchs, F. Ryter, C. F. Maggi, M. Balden, P. Martin, R. Riedl, Philipp Lauber, Frank Jenko, I. Radivojevic, L. Giannone, M. Maraschek, B. Zaniol, G. Haas, A. Mück, Gerhard Raupp, C. Tichmann, R. Merkel, H. F. Meyer, E. Strumberger, Martin Jakobi, D. Zasche, G. Becker, M. Garcia Munoz, K. Lackner, Y.P. Chen, W. Sandmann, O. J. W. F. Kardaun, K.-H. Steuer, Analiza M. Silva, F. Braun, A. G. Peeters, O. Gruber, F. Leuterer, A. Lyssoivan, W. Suttrop, A. Kallenbach, V. Mertens, K. K. Kirov, Bruce D. Scott, F. Wesner, Y.-S. Na, M. Münich, E. Quigley, C. Angioni, R. Lorenzini, Ivan Bizyukov, Michael Kaufmann, S. Kálvin, H. P. Zehrfeld, K.H. Behringer, W. Becker, Yasutaro Nishimura, A. Carlson, Daisuke Nishijima, M. Mayer, Hajime Urano, S. Cirant, A. Manini, T. Ribeiro, D. Borba, K. Engelhardt, B. Streibl, Junghee Kim, K. Dimova, H. Meister, M. Troppmann, S. Saarelma, Ursel Fantz, J. Hobirk, S. D. Pinches, F. Monaco, Emanuele Poli, Sheena Menmuir, Marco Brambilla, W. Kraus, A. Geier, H. Maier, S. Schweizer, G. Schramm, D. Merkl, S. W. Yoon, R. Neu, E. Speth, R. Bilato, A. V. Chankin, Thomas Zehetbauer, M. Tsalas, Julia Fuchs, M. Huart, J. Gafert, Fernando Meo, Alexander Kendl, T. Bolzonella, R. Drube, R. Dux, G. Tardini, K. Borrass, B. Heger, G. Pautasso, H. D. Murmann, Th. Pütterich, J. Chen, D. Meisel, K. Behler, J. Schirmer, V. Rohde, Wolf-Dieter Schneider, A. Lohs, G. Gantenbein, K. F. Mast, C. V. Atanasiu, G. Schall, A. Stäbler, A. Buhler, H. W. Müller, P. Varela, D. Strintzi, V. Bobkov, K. Gal, A. C. C. Sips, A. Jacchia, H. Kollotzek, Peter Lang, J. M. Santos, W. Treutterer, M. Apostoliceanu, M. Zilker, J. Neuhauser, M. Reich, P. Franzen, Tilman Dannert, J. Roth, H.-U. Fahrbach, Bernd Heinemann, M. E. Manso, D. A. Hartmann, C. Sihler, J. Stober, L. Fattorini, Isabel L. Nunes, H. Zohm, M. Kick, D. Wagner, A. Keller, Martin Laux, Jari Likonen, Taina Kurki-Suonio, E. Posthumus-Wolfrum, D. P. Coster, J. Schweinzer, G. Kocsis, M. Y. Ye, H. Hohenöcker, H. B. Schilling, C. Konz, P. Mantica, V. Igochine, G. Neu, Sibylle Günter, G. V. Pereverzev, L. D. Horton, Patrick J. McCarthy, M. Foley, A. Lorenz, and J.-M. Noterdaeme

Subjects
Nuclear and High Energy Physics, Materials science, Tokamak, Nuclear engineering, Automatic frequency control, fusion reactors, Electron, Parameter space, 7. Clean energy, 01 natural sciences, Particle transport, Electron cyclotron resonance, 010305 fluids & plasmas, ASDEX Upgrade, ITER, 0103 physical sciences, 010306 general physics, plasma, Magnetic confinement fusion, Condensed Matter Physics, fusion energy, ___, JET, Atomic physics, Control methods
Abstract

Significant progress has been made on ASDEX Upgrade during the last two years in the basic understanding of transport, in the extension of the improved H-mode in parameter space and towards an integrated operating scenario and in the development of control methods for major performance limiting instabilities. The important features were the understanding of particle transport and the control of impurity accumulation based on it, the satisfactory operation with predominantly tungsten-clad walls, the improved H-mode operation over density ranges and for temperature ratios covering (non-simultaneously) the ITER requirements on ν*, n/nGW and Te/Ti, the ELM frequency control by pellet injection and the optimization of NTM suppression by DC-ECCD through variation of the launching angle. From these experiments an integrated scenario has emerged which extrapolates to a 50% improvement in n T τ or a 30% reduction of the required current when compared with the ITER base-line assumptions, with moderately peaked electron and controllable high-Z density profiles.

Published
2005
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2. Overview of ASDEX Upgrade results

Author

O. Gruber, R. Arslanbekov, C. Atanasiu, A. Bard, G. Becker, W. Becker, M. Beckmann, K. Behler, K. Behringer, A. Bergmann, R. Bilato, D. Bolshukin, K. Borrass, H.-S. Bosch, B. Braams, M. Brambilla, R. Brandenburg, F. Braun, H. Brinkschulte, R. Brückner, B. Brüsehaber, K. Büchl, A. Buhler, H. Bürbaumer, A. Carlson, M. Ciric, G. Conway, D.P. Coster, C. Dorn, R. Drube, R. Dux, S. Egorov, W. Engelhardt, H.-U. Fahrbach, U. Fantz, H. Faugel, M. Foley, P. Franzen, P. Fu, J.C. Fuchs, J. Gafert, G. Gantenbein, O. Gehre, A. Geier, J. Gernhardt, E. Gubanka, A. Gude, S. Günter, G. Haas, D. Hartmann, B. Heinemann, A. Herrmann, J. Hobirk, F. Hofmeister, H. Hohenöcker, L. Horton, L. Hu, D. Jacobi, M. Jakobi, F. Jenko, A. Kallenbach, O. Kardaun, M. Kaufmann, A. Kendl, J.-W. Kim, K. Kirov, R. Kochergov, H. Kollotzek, W. Kraus, K. Krieger, B. Kurzan, G. Kyriakakis, K. Lackner, P.T. Lang, R.S. Lang, M. Laux, L. Lengyel, F. Leuterer, A. Lorenz, H. Maier, K. Mank, M.-E. Manso, M. Maraschek, K.-F. Mast, P.J. McCarthy, D. Meisel, H. Meister, F. Meo, R. Merkel, V. Mertens, J.P. Meskat, R. Monk, H.W. Müller, M. Münich, H. Murmann, G. Neu, R. Neu, J. Neuhauser, J.-M. Noterdaeme, I. Nunes, G. Pautasso, A.G. Peeters, G. Pereverzev, S. Pinches, E. Poli, R. Pugno, G. Raupp, T. Ribeiro, R. Riedl, S. Riondato, V. Rohde, H. Röhr, J. Roth, F. Ryter, H. Salzmann, W. Sandmann, S. Sarelma, S. Schade, H.-B. Schilling, D. Schlögl, K. Schmidtmann, R. Schneider, W. Schneider, G. Schramm, J. Schweinzer, S. Schweizer, B.D. Scott, U. Seidel, F. Serra, S. Sesnic, C. Sihler, A. Silva, A. Sips, E. Speth, A. Stäbler, K.-H. Steuer, J. Stober, B. Streibl, E. Strumberger, W. Suttrop, A. Tabasso, A. Tanga, G. Tardini, C. Tichmann, W. Treutterer, M. Troppmann, N. Tsois, W. Ullrich, M. Ulrich, P. Varela, O. Vollmer, U. Wenzel, F. Wesner, R. Wolf, E. Wolfrum, R. Wunderlich, N. Xantopoulos, Q. Yu, M. Zarrabian, D. Zasche, T. Zehetbauer, H.-P. Zehrfeld, A. Zeiler, and H. Zohm

Subjects
Nuclear and High Energy Physics, 0103 physical sciences, 010306 general physics, Condensed Matter Physics, 01 natural sciences, 010305 fluids & plasmas
Published
2001
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3. Operational behaviour of the ASDEX upgrade in-vessel cryo pump

Author

K Schindler, B. Streibl, H. Kollotzek, G. Schall, V. Rohde, A Kaltenberger, and K. Mattes

Subjects
Materials science, Continuous operation, Mechanical Engineering, Nuclear engineering, Mass flow, Transfer line, chemistry.chemical_element, Cryopump, Fusion power, Nuclear physics, Nuclear Energy and Engineering, chemistry, ASDEX Upgrade, General Materials Science, Circulating pump, Helium, Civil and Structural Engineering
Abstract

The set-up of the Helium (He) supply circuit for the ASDEX Upgrade cryo pump (CP) with 100 m3/s Deuterium pumping speed is described together with the key instrumentation and the method of data interpretation. The main peculiarities of the CP operation are the hydraulic instability of the mass flow below 4 g/s, due to large level differences of the transfer line and the sudden heat input of 130 W to the cryo panel during He discharge cleaning of the vacuum vessel. In both cases, a maintenance free, immersed Helium Circulating Pump (HCP), simplifies operation considerably. It permits quick re-filling and re-cooling after He-glowing and stabilisation of the standby mass flow in an oscillatory way down to 2.5 g/s. The measured He losses show that continuous operation of the CP, including He-glowing, is feasible even with a standard 30/60 l/h He-liquifier.

Published
2001
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4. Automatic setting of machine control with physics operation parameters at ASDEX Upgrade

Author

D Zasche, D Jacobi, H Kollotzek, G Neu, G Raupp, B Streibl, W Treuttererer, Th Zehetbauer, and the ASDEX Upgrade Team

Subjects
business.industry, Mechanical Engineering, Control engineering, Automation, Task (project management), Software, Nuclear Energy and Engineering, ASDEX Upgrade, Control system, General Materials Science, Session (computer science), Actuator, business, Civil and Structural Engineering, Machine control
Abstract

Performing plasma fusion experiments in a tokamak relies on close cooperation between discharge control (DCS) and machine control (MCS) systems, where the DCS's task is generating and handling the plasma, and the MCS is responsible for providing and configuring the necessary actuators. With a reduced number of experiment cycles per day, in consequence of long pulses or ambitious discharge scenarios, optimal utilization of resources as well as avoiding mismatches between the MCS’ and DCS’ configurations becomes increasingly important. Setting up the MCS for discharges currently relies on informal communication and requires careful attention of operators and session leaders. To enforce correspondence between MCS and DCS parametrizations, an automatic mediator agent formalizes the pre-shot configuration procedure. Functionality of the mediator and protocols for embedding into the existing system are discussed.

Published
2000
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5. Overview of ASDEX Upgrade results

Author

O Gruber, H.-S Bosch, S Günter, A Herrmann, A Kallenbach, M Kaufmann, K Krieger, K Lackner, V Mertens, R Neu, F Ryter, J Schweinzer, A Stäbler, W Suttrop, R Wolf, K Asmussen, A Bard, G Becker, K Behler, K Behringer, A Bergmann, M Bessenrodt-Weberpals, K Borrass, B Braams, M Brambilla, R Brandenburg, F Braun, H Brinkschulte, R Brückner, B Brüsehaber, K Büchl, A Buhler, H.P Callaghan, A Carlson, D.P Coster, L Cupido, S. de Peña Hempel, C Dorn, R Drube, R Dux, S Egorov, W Engelhardt, H.-U Fahrbach, U Fantz, H.-U Feist, P Franzen, J.C Fuchs, G Fussmann, J Gafert, G Gantenbein, O Gehre, A Geier, J Gernhardt, E Gubanka, A Gude, G Haas, K Hallatschek, D Hartmann, B Heinemann, G Herppich, W Herrmann, F Hofmeister, E Holzhauer, D Jacobi, M Kakoulidis, N Karakatsanis, O Kardaun, A Khutoretski, H Kollotzek, S Kötterl, W Kraus, B Kurzan, G Kyriakakis, P.T Lang, R.S Lang, M Laux, L.L Lengyel, F Leuterer, A Lorenz, H Maier, M Manso, M Maraschek, M Markoulaki, K.-F Mast, P.J McCarthy, D Meisel, H Meister, R Merkel, J.P Meskat, H.W Müller, M Münich, H Murmann, B Napiontek, G Neu, J Neuhauser, M Niethammer, J.-M Noterdaeme, G Pautasso, A.G Peeters, G Pereverzev, S Pinches, G Raupp, K Reinmüller, R Riedl, V Rohde, H Röhr, J Roth, H Salzmann, W Sandmann, H.-B Schilling, D Schlögl, K Schmidtmann, H Schneider, R Schneider, W Schneider, G Schramm, S Schweizer, R.R Schwörer, B.D Scott, U Seidel, F Serra, S Sesnic, C Sihler, A Silva, E Speth, K.-H Steuer, J Stober, B Streibl, A Thoma, W Treutterer, M Troppmann, N Tsois, W Ullrich, M Ulrich, P Varela, H Verbeek, O Vollmer, H Wedler, M Weinlich, U Wenzel, F Wesner, R Wunderlich, N Xantopoulos, Q Yu, D Zasche, T Zehetbauer, H.-P Zehrfeld, H Zohm, and M Zouhar

Subjects
Nuclear and High Energy Physics, 0103 physical sciences, 010306 general physics, Condensed Matter Physics, 01 natural sciences, 010305 fluids & plasmas
Published
1999
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6. The compatibility of high confinement times and complete divertor detachment in ASDEX-Upgrade

Author

Gerhard Raupp, H. Salzmann, H. Röhr, F. Ryter, B. Streibl, F. Serra, K. Krieger, J. Roth, H. Kollotzek, Peter Lang, P. Varela, G. Schramm, W. Suttrop, A. R. Field, H. D. Murmann, M. Ulrich, G. Becker, W. Poschenrieder, K. Behler, G. Haas, Albrecht Herrmann, W. Engelhardt, Dirk Naujoks, O. Vollmer, Harald Schneider, M. Sokoll, S. Hirsch, Cs S. Pitcher, T. Kass, Sdp De Pena Hempel, Hb-B. Schilling, A. Stäbler, M. Niethammer, U. Wenzel, G. Fieg, Wp P. West, B. Kurzan, M. Troppmann, Me E. Manso, M. Alexander, B. Napiontek, B. Jüttner, E. Speth, V. Mertens, R. Merkel, O. Gehre, L. Cupido, M. Bessenrodt-Weberpals, O. Gruber, G. Lieder, H. Wedler, R. Drube, R. Dux, Hp P. Zehrfeld, U. Seidel, R. Chodura, C. Dorn, W. Treutterer, M. Schittenhelm, Kf F. Mast, Carmen García-Rosales, F. Wesner, D. Meisel, J. Gernhardt, R. Lang, H.-S. Bosch, Thomas Zehetbauer, Ch. Fuchs, K. Schonmann, G. Pautasso, G. Neu, J. Neuhauser, Hu U. Fahrbach, S. Fiedler, R. Wunderlich, M. Maraschek, J. Stober, H. Zohm, K.H. Behringer, Ralf Schneider, Patrick J. McCarthy, Kh-H. Steuer, P. Ignacz, W. Köppendörfer, K. Lackner, W. Sandmann, Hj J. DeBlank, Hu U. Feist, Wolf-Dieter Schneider, A. Kallenbach, Jm-M. Noterdaeme, R. Neu, M. Weinlich, Michael Kaufmann, W. Junker, A. Carlson, Marco Brambilla, S. Deschka, Martin Laux, A. Silva, K. Asmussen, D. P. Coster, J. Schweinzer, G. Fussmann, W. Herrmann, K. Büchl, M. Albrecht, and D. Zasche

Subjects
Materials science, Divertor, chemistry.chemical_element, Radiation, Condensed Matter Physics, Neon, Nuclear Energy and Engineering, Deuterium, chemistry, ASDEX Upgrade, Mathematics::K-Theory and Homology, Physics::Plasma Physics, Impurity, Atomic physics
Abstract

The completely detached high confinement (CDH) regime established recently in high power ASDEX-Upgrade single null divertor discharges is described. The standard CDH mode scenario with feedback controlled external deuterium and neon puffing is analysed in detail with respect to its divertor detachment and confinement properties. Impurity transport and pumping effects and the density operation windows of the CDH mode are outlined. First results with other impurity radiators (N,Ar) are given. Finally the CDH mode operation space is discussed in terms of main chamber and scrape-off layer plus divertor radiation and possible consequences for future fusion experiments are outlined.

Published
1995
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7. Overview of ASDEX Upgrade results

Author

A. Kallenbach, J. Adamek, L. Aho-Mantila, S. Äkäslompolo, C. Angioni, C.V. Atanasiu, M. Balden, K. Behler, E. Belonohy, A. Bergmann, M. Bernert, R. Bilato, V. Bobkov, J. Boom, A. Bottino, F. Braun, M. Brüdgam, A. Buhler, A. Burckhart, A. Chankin, I.G.J. Classen, G.D. Conway, D.P. Coster, P. de Marné, R. D'Inca, R. Drube, R. Dux, T. Eich, N. Endstrasser, K. Engelhardt, B. Esposito, E. Fable, H.-U. Fahrbach, L. Fattorini, R. Fischer, A. Flaws, H. Fünfgelder, J.C. Fuchs, K. Gál, M. García Muñoz, B. Geiger, M. Gemisic Adamov, L. Giannone, C. Giroud, T. Görler, S. da Graca, H. Greuner, O. Gruber, A. Gude, S. Günter, G. Haas, A.H. Hakola, D. Hangan, T. Happel, T. Hauff, B. Heinemann, A. Herrmann, N. Hicks, J. Hobirk, H. Höhnle, M. Hölzl, C. Hopf, L. Horton, M. Huart, V. Igochine, C. Ionita, A. Janzer, F. Jenko, C.-P. Käsemann, S. Kálvin, O. Kardaun, M. Kaufmann, A. Kirk, H.-J. Klingshirn, M. Kocan, G. Kocsis, H. Kollotzek, C. Konz, R. Koslowski, K. Krieger, T. Kurki-Suonio, B. Kurzan, K. Lackner, P.T. Lang, P. Lauber, M. Laux, F. Leipold, F. Leuterer, A. Lohs, N.C. Luhmann, T. Lunt, A. Lyssoivan, H. Maier, C. Maggi, K. Mank, M.-E. Manso, M. Maraschek, P. Martin, M. Mayer, P.J. McCarthy, R. McDermott, H. Meister, L. Menchero, F. Meo, P. Merkel, R. Merkel, V. Mertens, F. Merz, A. Mlynek, F. Monaco, H.W. Müller, M. Münich, H. Murmann, G. Neu, R. Neu, B. Nold, J.-M. Noterdaeme, H.K. Park, G. Pautasso, G. Pereverzev, Y. Podoba, F. Pompon, E. Poli, K. Polochiy, S. Potzel, M. Prechtl, M.J. Püschel, T. Pütterich, S.K. Rathgeber, G. Raupp, M. Reich, B. Reiter, T. Ribeiro, R. Riedl, V. Rohde, J. Roth, M. Rott, F. Ryter, W. Sandmann, J. Santos, K. Sassenberg, P. Sauter, A. Scarabosio, G. Schall, K. Schmid, P.A. Schneider, W. Schneider, G. Schramm, R. Schrittwieser, J. Schweinzer, B. Scott, M. Sempf, F. Serra, M. Sertoli, M. Siccinio, A. Sigalov, A. Silva, A.C.C. Sips, F. Sommer, A. Stäbler, J. Stober, B. Streibl, E. Strumberger, K. Sugiyama, W. Suttrop, T. Szepesi, G. Tardini, C. Tichmann, D. Told, W. Treutterer, L. Urso, P. Varela, J. Vincente, N. Vianello, T. Vierle, E. Viezzer, C. Vorpahl, D. Wagner, A. Weller, R. Wenninger, B. Wieland, C. Wigger, M. Willensdorfer, M. Wischmeier, E. Wolfrum, E. Würsching, D. Yadikin, Q. Yu, I. Zammuto, D. Zasche, T. Zehetbauer, Y. Zhang, M. Zilker, H. Zohm, and Science and Technology of Nuclear Fusion

Subjects
PHYSICS, Nuclear and High Energy Physics, 0103 physical sciences, TOKAMAK, 010306 general physics, Condensed Matter Physics, 7. Clean energy, 01 natural sciences, 010305 fluids & plasmas, REFLECTOMETRY
Abstract

The ASDEX Upgrade programme is directed towards physics input to critical elements of the ITER design and the preparation of ITER operation, as well as addressing physics issues for a future DEMO design. After the finalization of the tungsten coating of the plasma facing components, the re-availability of all flywheel-generators allowed high-power operation with up to 20 MW heating power at I p up to 1.2 MA. Implementation of alternative ECRH schemes (140 GHz O2- and X3-mode) facilitated central heating above n e = 1.2 × 1020 m−3 and low q 95 operation at B t = 1.8 T. Central O2-mode heating was successfully used in high P/R discharges with 20 MW total heating power and divertor load control with nitrogen seeding. Improved energy confinement is obtained with nitrogen seeding both for type-I and type-III ELMy conditions. The main contributor is increased plasma temperature, no significant changes in the density profile have been observed. This behaviour may be explained by higher pedestal temperatures caused by ion dilution in combination with a pressure limited pedestal and hollow nitrogen profiles. Core particle transport simulations with gyrokinetic calculations have been benchmarked by dedicated discharges using variations of the ECRH deposition location. The reaction of normalized electron density gradients to variations of temperature gradients and the T e/T i ratio could be well reproduced. Doppler reflectometry studies at the L–H transition allowed the disentanglement of the interplay between the oscillatory geodesic acoustic modes, turbulent fluctuations and the mean equilibrium E × B flow in the edge negative E r well region just inside the separatrix. Improved pedestal diagnostics revealed also a refined picture of the pedestal transport in the fully developed H-mode type-I ELM cycle. Impurity ion transport turned out to be neoclassical in between ELMs. Electron and energy transport remain anomalous, but exhibit different recovery time scales after an ELM. After recovery of the pre-ELM profiles, strong fluctuations develop in the gradients of n e and T e. The occurrence of the next ELM cannot be explained by the local current diffusion time scale, since this turns out to be too short. Fast ion losses induced by shear Alfvén eigenmodes have been investigated by time-resolved energy and pitch angle measurements. This allowed the separation of the convective and diffusive loss mechanisms.

Published
2011
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8. Edge physics and H-mode studies in ASDEX Upgrade

Author

K.H. Behringer, G. Becker, R. Neu, B. Streibl, F. Serra, H. M. Mayer, J. Roth, F. Hofmeister, M. E. Manso, G. Venus, K. Lackner, W. Sandmann, D. Jacobi, K Behler, H. P. Zehrfeld, A. Kallenbach, O. J. W. F. Kardaun, A. Eberhagen, R. Wilhelm, G. Haas, R. Wunderlich, W. Engelhardt, H. B. Schilling, M. Münich, de Pena, Harald Richter, J. Neuhauser, H U Fahrbach, M. Alexander, G. Herppich, E. Speth, R Drube, H. J. de Blank, S. D. Hempel, A. Silva, H. Hohenöcker, Neil A. Salmon, G. Lieder, O de Barbieri, R. Merkel, T. Kass, W. Köppendörfer, M. Ulrich, K. Asmussen, Dirk Naujoks, F. Leuterer, M. Schittenhelm, J. Gernhardt, V. Mertens, O. Gruber, M. Weinlich, Ralf Schneider, Patrick J. McCarthy, M. Bessenrodt-Weberpals, H. Vernickel, R. Lang, Carmen García-Rosales, K.-H. Steuer, G. Fussmann, W. Suttrop, Ch. Fuchs, S. Götsch, Bruce D. Scott, D. Zasche, K. Schonmann, F. Braun, J. Gruber, J.-H. Feist, M. Laux, M. Troppmann, H. Röhr, H. Salzmann, K. Kiemer, F. Ryter, K. Büchl, U. Schumacher, W. Feneberg, G. Schramm, M. Albrecht, W. Poschenrieder, A. Hermann, K Gunther, C. S. Pitcher, J. Schweinzer, K. F. Mast, O. Gehre, A. Stäbler, B. Kurzan, H. Schneider, N. Tsois, B. Jüttner, L. Cupido, U. Seidel, T. Richter, O. Vollmer, J.-M. Noterdaeme, C. Dorn, G. Neu, Gerhard Raupp, K. Krieger, G. Fieg, L. Lengyel, B. Heinemann, A. R. Field, D. Meisel, F. X. Söldner, A Bergmann, W Schneider, H. Zohm, Hans-Stephan Bosch, B. Napiontek, Michael Kaufmann, W. Junker, A. Carlson, Marco Brambilla, H. Kollotzek, Peter Lang, R. Chodura, W. Treutterer, P. Varela, W Herrmann, U. Wenzel, M. Kornherr, H. D. Murmann, H. Wedler, J. Engstler, F. Wesner, and G. Pautasso

Subjects
Nuclear physics, Physics, Toroid, Nuclear Energy and Engineering, ASDEX Upgrade, Physics::Plasma Physics, Sputtering, Divertor, Boundary (topology), Plasma, Edge (geometry), Condensed Matter Physics, Magnetic field
Abstract

ASDEX Upgrade is a poloidal divertor experiment very similar to ITER with respect to magnetic field properties and especially to the plasma boundary geometry. A large part of the programme on ASDEX Upgrade is therefore dedicated to investigating and optimizing reactor-relevant plasma boundary issues. This contribution is concerned with H-mode studies and edge physics in general. The L/H-power threshold, H-mode confinement, details of ELM dynamic and 'dithering' L/H-transitions will be discussed. The edge physics investigations are concerned with model calculations and validations, the characteristic 'approach' to the density limit (DL), target plate sputtering and the influence of hydrocarbons, asymmetries and drifts depending on the direction of the toroidal magnetic field, and finally first results of high-Z material experiments.

Published
1993
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9. A new centrifuge pellet injector for fusion experiments

Author

G. Prausner, P. Cierpka, Gregorio Weber, H. Kollotzek, R.S. Lang, Peter Lang, M. Ulrich, E. Buchelt, C. Andelfinger, and F. X. Söldner

Subjects
Centrifuge, Acceleration, Materials science, Tokamak, ASDEX Upgrade, law, Nuclear engineering, Pellet, Pellets, Injector, Instrumentation, law.invention, Cylinder (engine)
Abstract

This paper reports on the new pellet injection system for refueling the ASDEX Upgrade tokamak with cubic H2 or D2 pellets having alternative side lengths of 1.5, 1.75, and 2.0 mm and optional Ne doping. The system delivers series of about 100 pellets at a maximum repetition rate of more than 40 Hz. The pellets are accelerated by means of a centrifuge with an optimized straight acceleration arm. This configuration minimizes the compulsive force acting on the pellet during the acceleration process. Since this also minimizes stresses inside the pellet, high velocities—a maximum of 1211 m/s being achieved—are possible without destroying the hydrogen cubes. A special pellet feed‐in technique based on a static stop cylinder interrupting the acceleration path successfully reduced the horizontal scattering angle to values of less than ±4°; a high efficiency, with more than 90% of the pellets arriving within the acceptance angle, was thus achieved. The whole system was found to work very reliably and reproducibly during the whole test operation period, covering about 105 pellet shots, and is now being integrated into the ASDEX upgrade experiment.

Published
1993
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10. Addendum to papers from Axially Symmetric Divertor Experiment (ASDEX) Upgrade Team, published in Review of Scientific Instruments

Author

T. Eich, D. Yadikin, P. de Marne, Piero Martin, C. Tichmann, T. Lunt, K. Behler, A. Kammel, E. Strumberger, G. Tardini, K.H. Behringer, G. D. Conway, Bill Scott, F. Monaco, M. Rott, Manfred Zilker, A. Stäbler, K. Krieger, Taina Kurki-Suonio, G. Haas, G. Koscis, B. Streibl, R. Merkel, M. Mantsinen, L. Urso, B. Langer, A. Gude, A. Kirk, J. Stober, H. Doerk-Bendig, T. Hauff, M. Gemisic Adamov, G. Schall, H. Zohm, H.-J. Klingshirn, Karl Schmid, J. M. Santos, Emanuele Poli, K. McCormick, J. Neuhauser, A. Kagarmanov, J. Hobirk, D. Wagner, D. Zasche, Fernando Meo, A. Herrmann, Michael Kaufmann, W. Suttrop, E. Würsching, M. Reich, C. Angioni, G. Pautasso, N. Hicks, G. Antar, C. Wigger, B. Kurzan, H. Meister, Wolf-Dieter Schneider, V. Rohde, C. Vorpahl, Martin Laux, A. Lohs, Jari Likonen, M. Sertoli, D. P. Coster, P. Varela, O. J. W. F. Kardaun, J. Schweinzer, A. Lyssoivan, C. Konz, M. Püschel, M. Manso, L. Fattorini, S. Kálvin, K. Gal, H. Greuner, S. da Graca, Analiza M. Silva, Marco Brambilla, E. Wolfrum, K. Sassenberg, R. Bilato, M. Huart, R. Fischer, M. Münich, K. Mank, V. Mertens, H. Kollotzek, P. Merkel, L. Giannone, H. D. Murmann, N. Hammer, M. Sempf, M. Hölzl, M. Maraschek, Peter Lang, B. Reiter, Sibylle Günter, J. Roth, Lin Liu, H.-U. Fahrbach, Bernd Heinemann, P. Sauter, W. Treutterer, C. V. Atanasiu, I. Classen, U. Seidel, G. V. Pereverzev, Roman Schrittwieser, O. Gruber, R. Riedl, Cary Forest, Patrick J. McCarthy, A. Bergmann, Julia Fuchs, Philipp Lauber, V. Igochine, J. Adamek, F. Ryter, S. Potzel, Tobias Görler, M. Janzer, H. W. Müller, M. Brüdgam, F. Merz, E. Speth, A. Mlynek, M. Garcia-Munoz, F. Serra, E. Vainonen-Ahlgren, M. Balden, J.-M. Noterdaeme, M. Kick, H. F. Meyer, N. Endstrasser, A. V. Chankin, Gerhard Raupp, Mattia Siccinio, Frank Jenko, K.-H. Steuer, Alberto Bottino, K. Engelhardt, T. Pütterich, Q. Yu, R. Drube, R. Dux, A. Sigalov, K. Lackner, Christian Hopf, W. Sandmann, A. Scarabosio, A. Buhler, A. Kallenbach, Thomas Zehetbauer, T. Ribeiro, R. Neu, R. M. McDermott, M. Mayer, R. D’Inca, D. Holtum, F. Braun, G. Neu, B. Nold, J. E. Boom, D. Dodt, R. Stadler, S. Gori, V. Bobkov, M. Wischmeier, F. Leuterer, Peter Schneider, and W. Becker

Subjects
Scientific instrument, Physics, ASDEX Upgrade, Divertor, Nuclear engineering, Addendum, Axial symmetry, Instrumentation, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries)
Abstract

This addendum applies to papers authored by contributors from the Axially Symmetric Divertor Experiment (ASDEX) Upgrade Team published in Review of Scientific Instruments. This addendum provides the full list of ASDEX Upgrade Team contributors and their affiliations.

Published
2010
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11. Plasma wall interaction and its implication in an all tungsten divertor tokamak

Author

Emanuele Poli, Y. R. Martin, L. Fattorini, Fernando Meo, M. Sertoli, G. Tardini, M. Garcia Munoz, T T Ribeiro, Qiang Yu, E. Vainonen-Ahlgren, Laure Vermare, G. Haas, K. Lackner, W. Sandmann, O. J. W. F. Kardaun, M. Rott, R. Merkel, K.-H. Steuer, Piero Martin, A. Kallenbach, P. de Marne, K. Gál, Alberto Bottino, N. Hicks, M. Gemisic-Adamov, Michael Kaufmann, Bruce D. Scott, A. Gude, J. Stober, H. Zohm, V. Mertens, H. D. Murmann, C. V. Atanasiu, K.H. Behringer, D. Wagner, V. Igochine, J.-M. Noterdaeme, Th. Pütterich, K. Sassenberg, A. Flaws, M. Püschel, F. Serra, G. Neu, H. Kollotzek, A. Bergmann, R. Pugno, H. W. Müller, W. Schustereder, K. McCormick, H. Meister, H. Greuner, R. Bilato, M. Huart, Wolf-Dieter Schneider, A. Lohs, R. Schrittwieser, W. Becker, F. Ryter, F. Merz, V. Bobkov, H. F. Meyer, M. Mlynek, Julia Fuchs, M. Mayer, C. F. Maggi, D. Holtum, F. Braun, Peter Lang, J. Hobirk, Taina Kurki-Suonio, A. C. C. Sips, S. da Graca, W. Suttrop, M. Balden, Marco Brambilla, T. Eich, H. Maier, J. M. Santos, M. Wischmeier, C. Tröster, Garrard Conway, E. Würsching, B. Nold, T. Bertoncelli, B. Reiter, M. Zilker, Ana Elisa Bauer de Camargo Silva, Ch. Hopf, C. Angioni, Sibylle Günter, A. Stäbler, R. Riedl, E. Speth, G. Kocsis, Thomas Zehetbauer, Philipp Lauber, S. Kálvin, J. Schirmer, G. V. Pereverzev, K. Engelhardt, C. Tichmann, E. Wolfrum, P. Varela, A. Manini, Patrick J. McCarthy, J. Harhausen, J. Roth, S. Gori, H.-U. Fahrbach, A. Scarabosio, Bernd Heinemann, L. D. Horton, M. E. Manso, Lin Liu, A. Schmid, P. Merkel, Rudolf Neu, D. Yadikin, L. Giannone, C. Konz, M. Maraschek, F. Monaco, E. Strumberger, R. Fischer, J. Fink, K. Mank, S. Dietrich, G. Pautasso, R. Drube, R. Dux, V. Rohde, A. Sigalov, A. Buhler, Martin Laux, Jari Likonen, D. P. Coster, J. Schweinzer, L. Urso, G. Schall, D. Zasche, Ursel Fantz, G. Schramm, A. V. Chankin, K. Behler, Gerhard Raupp, K. Krieger, O. Gruber, K. Dimova, S. Schweizer, J. Neuhauser, A. Herrmann, M. Reich, B. Kurzan, P. Franzen, U. Seidel, M. Kick, and W. Treutterer

Subjects
Tokamak, Materials science, Divertor, Facing Components, Transport, chemistry.chemical_element, Flux, Plasma, Effective radiated power, Tungsten, Condensed Matter Physics, law.invention, Nuclear Energy and Engineering, Alcator C-Mod, chemistry, ASDEX Upgrade, Erosion, law, Iter-Like Wall, Atomic physics, Asdex Upgrade Divertor, Operation
Abstract

ASDEX Upgrade has recently finished its transition towards an all-W divertor tokamak, by the exchange of the last remaining graphite tiles to W-coated ones. The plasma start-up was performed without prior boronization. It was found that the large He content in the plasma, resulting from DC glow discharges for conditioning, leads to a confinement reduction. After the change to D glow for inter-shot conditioning, the He content quickly dropped and, in parallel, the usual H-Mode confinement with H factors close to one was achieved. After the initial conditioning phase, oxygen concentrations similar to that in previous campaigns with boronizations could be achieved. Despite the removal of all macroscopic carbon sources, no strong change in C influxes and C content could be observed so far. The W concentrations are similar to the ones measured previously in discharges with old boronization and only partial coverage of the surfaces with W. Concomitantly it is found that although the W erosion flux in the divertor is larger than the W sources in the main chamber in most of the scenarios, it plays only a minor role for the W content in the main plasma. For large antenna distances and strong gas puffing, ICRH power coupling could be optimized to reduce the W influxes. This allowed a similar increase of stored energy as yielded with comparable beam power. However, a strong increase of radiated power and a loss of H-Mode was observed for conditions with high temperature edge plasma close to the antennas. The use of ECRH allowed keeping the central peaking of the W concentration low and even phases of improved H-modes have already been achieved.

Published
2007
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12. Overview of ASDEX Upgrade results

Author

H. Zohm 1), C. Angioni 1), R. Arslanbekov 1), C. Atanasiu 2), G. Becker 1), W. Becker 1), K. Behler 1), K. Behringer 1), A. Bergmann 1), R. Bilato 1), V. Bobkov 1), D. Bolshukhin 1), T. Bolzonella 3), K. Borrass 1), M. Brambilla 1), F. Braun 1), A. Buhler 1), A. Carlson 1), G.D. Conway 1), D. P. Coster 1), R, Drube 1), R. Dux 1), S. Egorov 4), T. Eich 1), K. Engelhardt 1), H.-U. Fahrbach 1), U. Fantz 5), H. Faugel 1), K.H. Finken 6), M. Foley 7), P. Franzen 1), J. C. Fuchs 1), J. Gafert 1), K.B. Fournier 8), G. Gantenbein 9), O. Gehre 1), A. Geier 1), J. Gernhardt 1), T. Goodman 10), O. Gruber 1), A. Gude 1), S. G¨unter 1), G. Haas 1), D. Hartmann 1), B. Heger 5), B. Heinemann 1), A. Herrmann 1), J. Hobirk 1), F. Hofmeister 1), H. Hohen¨ocker 1), L. D. Horton 1), V. Igochine 1), A. Jacchia 11), M. Jakobi 1), F. Jenko 1), A. Kallenbach 1), O. Kardaun 1), M. Kaufmann 1), A. Keller 1), A. Kendl 1), J.-W. Kim 1), K. Kirov 1), R. Kochergov 1), H. Kollotzek 1), W. Kraus 1), K. Krieger 1), T. Kurki-Suonio 12) B. Kurzan 1), P. T. Lang 1), C. Lasnier, P. Lauber 1), M. Laux 1), A.W. Leonard 13), F. Leuterer 1), A. Lohs 1), A. Lorenz 1), R. Lorenzini 3), C. Maggi 1), H. Maier 1), K. Mank 1), M.-E. Manso 14), P. Mantica 12), M. Maraschek 1), E. Martines 3), K.-F. Mast 1), P. McCarthy 7), D. Meisel 1), H. Meister 1), F. Meo 1), P. Merkel 1), R. Merkel 1), D. Merkl 1), V. Mertens 1), F. Monaco 1), A.M¨uck 1), H.W.M¨uller 1), M.M¨unich 1), H.Murmann 1), Y.-S. Na 1), G. Neu 1), R. Neu 1), J. Neuhauser 1), F. Nguyen 15), D. Nishijima 1), Y. Nishimura 1), J.-M. Noterdaeme 1), I. Nunes 14), G. Pautasso 1), A. G. Peeters 1), G. Pereverzev 1), S. D. Pinches 1), E. Poli 1), M. Proschek 16), R. Pugno 1), E. Quigley 7), G. Raupp 1), M. Reich 1), T. Ribeiro 14), R. Riedl 1), V. Rohde 1), J. Roth 1), F. Ryter 1), S. Saarelma 12), W. Sandmann 1), A. Savtchkov 6), O. Sauter 10), S. Schade 1), H.-B. Schilling 1), W. Schneider 1), G. Schramm 1), E. Schwarz 1), J. Schweinzer 1), S. Schweizer 1), B. D. Scott 1), U. Seidel 1), F. Serra 14), S. Sesnic 1), C. Sihler 1), A. Silva 14), A. C. C. Sips 1), E. Speth 1), A. St¨abler 1), K.-H. Steuer 1), J. Stober 1), B. Streibl 1), E. Strumberger 1), W. Suttrop 1), A. Tabasso 1), A. Tanga 1), G. Tardini 1), C. Tichmann 1), W. Treutterer 1), M. Troppmann 1), H. Urano 1), P. Varela 14), O. Vollmer 1), D. Wagner 1), U. Wenzel 1), F. Wesner 1), E. Westerhof 17), R. Wolf 1), E. Wolfrum 1), E. W¨ursching 1), S.-W. Yoon 1), Q. Yu 1), D. Zasche 1), T. Zehetbauer 1), and H.-P. Zehrfeld 1)

Subjects
___
Abstract

Recent results from ASDEX Upgrade are presented. An improved understanding of energy and particle transport emerges in terms of a 'critical gradient' model for the temperature gradients. Coupling this to particle diffusion explains most of the observed behaviour of the density profiles, in particular the finding that strong central heating reduces the tendency for density profile peaking. Internal transport barriers with Te and Ti in excess of 20 keV (but not simultaneously) have been achieved. By shaping the plasma, a regime with small type II ELMs has been established. Here, the maximum power deposited on the target plates was greatly reduced at constant average power. Also, an increase of the ELM frequency by injection of shallow pellets was demonstrated. ELMfree operation is possible in the QH-mode regime previously found in DIII-D which has also been established on ASDEX Upgrade. Regarding stability, a regime with benign NTMs was found. During ECCD stabilisation of NTMs, bN could be increased well above the usual onset level without a reappearance of the NTM. ECRH and ECCD have also been used to control the sawtooth repetition frequency at a moderate fraction of the total heating power. The inner wall of the ASDEX Upgrade vessel has increasingly been covered with tungsten without detrimental effects on plasma performance. Regarding scenario integration, a scenario with a large fraction of noninductively driven current ( 50%), but without internal tranport barrier has been established. It combines improved confinement (tE=tITER98 1:2) and stability (bN 3:5) at high Greenwald fraction (ne=nGW 0:85) in steady state and with type II ELMy edge

Published
2003

13. Observation of continuous divertor detachment in H-mode discharges in ASDEX upgrade

Author

K. Kiemer, K. Büchl, M. Albrecht, O. Gruber, Michael Kaufmann, W. Junker, G. Haas, W. Engelhardt, Neil A. Salmon, A. Carlson, V. Mertens, W. Treutterer, Martin Laux, D. P. Coster, M. Bessenrodt-Weberpals, M. Sokoll, J. Schweinzer, K. Asmussen, Marco Brambilla, K.H. Behringer, W. Herrmann, D. Meisel, Ana Elisa Bauer de Camargo Silva, F. Wesner, S. Deschka, C. S. Pitcher, H. Kollotzek, R. Wunderlich, Peter Lang, D. Fieg, H. B. Schilling, Harald Richter, M. Ulrich, Dirk Naujoks, P. Varela, Carmen García-Rosales, K.-H. Steuer, H. U. Fahrbach, J.-M. Noterdaeme, C. Dorn, Ch. Fuchs, A. Eberhagen, K. Krieger, K. Schonmann, H. Röhr, F. Ryter, K. Lackner, W. Sandmann, G. Neu, H. P. Zehrfeld, H. D. Murmann, M. Alexander, T. Richter, O. Vollmer, A. Kallenbach, G. Lieder, R. Drube, R. Dux, H.-S. Bosch, W. Poschenrieder, G. Fußmann, M. Schittenhelm, J. Gernhardt, A. Stäbler, S. De Pena Hempel, R. Lang, M. Maraschek, W. Suttrop, W. Köppendörfer, Harald Schneider, A. R. Field, D. Zasche, H. Vernickel, U. Wenzel, M. Troppmann, M. Ballico, H. Salzmann, R. Neu, M. Kornherr, H. Wedler, E. Speth, Gerhard Raupp, M. E. Manso, Ralf Schneider, Patrick J. McCarthy, R. Merkel, B. Napiontek, U. Schumacher, B. Kurzan, B. Jüttner, L. Cupido, U. Seidel, G. Schramm, P. Ignacz, Wolf-Dieter Schneider, K. Behler, O. Gehre, K. F. Mast, G. Pautasso, J. Neuhauser, S. Fiedler, H. M. Mayer, J. Roth, M. Weinlich, H.J. DeBlank, H. U. Feist, Albrecht Herrmann, J. Stober, S. Hirsch, T. Kass, H. Zohm, B. Streibl, and F. Serra

Subjects
Materials science, DIII-D, Divertor, Mode (statistics), General Physics and Astronomy, chemistry.chemical_element, Plasma, Radiation, Neon, Energy confinement, Deuterium, chemistry, ASDEX Upgrade, Atomic physics
Abstract

Feedback-controlled puffing of neon and deuterium has been applied to control the edge-localized-mode behavior and the target plate power deposition during high-power H -mode discharges in ASDEX Upgrade. A regime has been found in which more than 90% of the heating power is lost through radiation and divertor detachment occurs, without deterioration of the energy confinement. The plasma remains in the H mode, exhibiting small-amplitude, high-frequency ELM's, which do not penetrate to the target plates in the strike zone region.

Published
1995

14. ASDEX UPGRADE: THE FIRST PERIOD OF OPERATION

Author

F. Wesner, J. Gernhardt, G. Schramm, H. Schneider, A. Wieczorek, J. Oswald, K. Behler, U. Seidel, Gerhard Raupp, W. Woyke, K. Mattes, D. Zasche, H. Finkelmeyer, Patrick J. McCarthy, H. Hupfloher, B. Streibl, V. Mertens, O. Gruber, H. Vernickel, J.-M. Noterdaeme, G. Klement, T. Richter, J. Ernesti, S. Schweizer, K. Lackner, W. Poschenrieder, Harald Richter, W. Koeppendoerfer, H. Kollotzek, G. Herppich, G. Neu, R. Drube, and D. Jacobi

Subjects
Materials science, ASDEX Upgrade, Nuclear engineering, Control system, Flux, Electron, Plasma, Effective radiated power, Instability, Power (physics)
Abstract

The first plasma in ASDEX Upgrade (AUG) was produced on 21stMarch '91 after more than 8 years of design, manufacture, and assembly. During the first operational period until August '92, with 1949 shots, the control and safety systems were commissioned in parallel with plasma discharges. Most discharges were run with He, but also H and D discharges were executed up to a plasma current of 800 kA at Bo = 2 T. With additional heating by ICRH, of up to 2.2 MW power and up to 2 s duration, the H-mode was obtained at a threshold of 1.2 MW after boronization. Discharges with line-densities of up to ne = 4*1019m−3and central electron temperatures of up to Teo =1.5 keV could adequately be diagnosed (ne-, Te-profiles, radiated power, ELM and MHD-activities, impurity influx …). With a CCD-camera the plasma boundary and critical in vessel components were observed. The magnetic diagnostics provided input for elaborate feedback control and reconstruction of the flux surfaces. The main effort of the experimental program was put on establishing the SN-divertor configuration, investigating the vertical n = 0 instability (VDE) and ICR heating scenarios. This paper describes the control systems, discharge essentials, vessel conditioning and the specific VDE behaviour.

Published
1993
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15. COMPLETION OF ASSEMBLY AND START OF TECHNICAL OPERATION OF ASDEX UPGRADE

Author

H. Vernickel, C. Dorn, F. Hartz, S. Schweitzer, H. Kollotzek, E. Kaplan, W. Woyke, E. Lackner, B. Streibl, G. Reichert, J. Owald, A. Wieczorek, H. Bruhns, F. Werner, M. Troppmann, J. Gruber, Harald Richter, D. Jacobi, W. Koeppendoerfer, G. Schramm, M. Pillsticker, Thomas Zehetbauer, J. Genhardt, P. Weng, Gerhard Raupp, H. Schneider, U. Seidel, X. Wang, M. Blaumoser, and G. Klement

Subjects
Supervisory systems, Tokamak, ASDEX Upgrade, Completion (oil and gas wells), law, Computer science, Magnet, Nuclear engineering, Plasma control system, Poloidal field, Electric power, law.invention
Abstract

The last important steps of the tokamak machine assembly are described. A survey of precision and tolerances is given achieved for the vacuum vessel, the toroidal field (TF) magnet and the poloidal field (PF) coils. The first commissioning tests of vacuum vessel, TF magnet and PF coils are described together with certain features of the control and technical supervisory system. Remarks on improvements of the electric power supply system and the fast plasma control system follow. Finally the programme of the next future is briefly outlined.

Published
1991
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16. A centrifuge pellet injector for ASDEX upgrade

Author

C. Andelfinger, K.H. Bernhardt, M. Ulrich, Gregorio Weber, and H. Kollotzek

Subjects
Cryostat, Centrifuge, Bearing (mechanical), Materials science, Rotor (electric), Nuclear engineering, Pellets, Condensed Matter Physics, Surfaces, Coatings and Films, law.invention, Acceleration, ASDEX Upgrade, law, Pellet, Instrumentation
Abstract

Plasma fuelling by pellet injection with deep particle deposition improves the plasma performance. Stationary conditions can be achieved with pellet frequencies of the order of 10 pellets per second. For medium-size experiments a centrifuge will be a suitable candidate that avoids the high gas flux of pneumatic guns. The pellet velocity will be limited to 1200m s−1 by stresses in the rotor material and compulsive forces acting on the pellets during acceleration. The best solution is an optimized straight acceleration arm made of Ti AL6 V4 alloy. Finite-element calculations confirmed maximum stresses of 600 MPa and a fatigue limit exceeding 107 load cycles for the operation conditions. The driver of the rotor, a TPH 5000, has a large moment of inertia compared with that of the rotor arm. This is helpful for balancing the combined system. Special care was taken to ensure a stiff bearing to avoid radial eccentricity and axial elevation in the case of high gas fluxes due to accidental break-down of the pellet-producing cryostat. Pellet production and feed-in are reported in Proceedings of 14th Symposium of Fusion Technology, 1986, p. 1349, Pergamon Press, Oxford.

Published
1990
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17. ASDEX upgrade: A poloidal divertor tokamak adapted to reactor requirements

Author

H. Vernickel, M. Blaumoser, K. Ennen, J. Gruber, O. Gruber, O. Jandl, M. Kaufmann, H. Kollotzek, W. Köppendörfer, H. Kotzlowski, E. Lackner, K. Lackner, J. Neuhauser, J.-M. Noterdaeme, M. Pillsticker, R. Pöhlchen, H. Preis, K.-G. Rauh, H. Röhr, H. Schneider, W. Schneider, U. Seidel, B. Sombach, B. Streibl, G. Venus, F. Wesner, and A. Wieczorek

Subjects
Nuclear and High Energy Physics, Tokamak, Toroid, Materials science, Nuclear engineering, Divertor, Energy flux, Plasma, law.invention, Nuclear physics, Nuclear Energy and Engineering, ASDEX Upgrade, law, Magnet, Heat shield, General Materials Science
Abstract

ASDEX Upgrade, a medium-size tokamak, is characterized by the following features: a poloidal field system with all coils located outside the TF magnet; elongated plasmas up to s = 1.6 in double-null (DN), single-null (SN) or limiter-controlled (L) configurations; a plasma current of up to I p ≈ 2 MA, which ensures reactor-like plasma boundary parameters; auxiliary heating (probably ICRH, 12 MW, 8 antennae) producing a reactor-equal energy flux density of 0.3 MW/m2 in the plasma boundary. The vacuum vessel installation is primarily adapted to SN divertor operation using two toroidal divertor plate arrays ≈ 3 m2 in area each. It allows DN divertor operation with reduced parameters. Proper adjustment of target plates, antennae and heat shields also allows full-parameter DN and L configurations to be studied. The aims of ASDEX Upgrade are to study the reactor-compatible open divertor configuration in the high-recycling, low-boundary-temperature regime. Boundary layer models promise adequate solutions for taking the plasma energy to the material structure in such a way that impurity production is kept sufficiently low and that proper steady-state plasma conditions can prevail. The condition for helium pumping can also be studied. The detailed design of the tokamak system is about to be completed; the first components have been ordered and construction work is scheduled for completion by the end of 1987.

Published
1984
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18. The ZEPHYR poloidal field coils

Author

F. Werner, U. Seidel, H. Kollotzek, and M. Pillsticker

Subjects
Stress (mechanics), Physics, Nuclear magnetic resonance, Electromagnetic coil, Plasma breakdown, Poloidal field, Plasma, Electrical and Electronic Engineering, Atomic physics, Supercritical fluid, Electronic, Optical and Magnetic Materials, Pulse (physics), Magnetic field
Abstract

The magnetic field of the poloidal coils creates plasma equilibrium conditions, plasma breakdown and heating and may be formed by two separate coil systems (OH; V). All coils without the central OH coil (OH 1) are normally stressed; less than 100 MPa. The extremely stressed OH central coil (350 MPa)must be specially designed for keeping stress and temperature rise low. The start temperature of OH 1 has to be less than 80 K for keeping the temperature rise i=9.1 \frac{KA}{cm^{2}} ; t pulse = 4.5 s. All coils are designed for direct cooling. Cool medium can be Li N2 or supercritical He at high pressure.

Published
1981
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19. The ASDEX Upgrade toroidal field magnet and poloidal divertor field coil system adapted to reactor requirements

Author

K. Lackner, R. Pöhlchen, F. Wesner, H. Preis, H. Kollotzek, F. Werner, E. Lackner, E. Speth, A. Wieczorek, T. von Larcher, H. Vernickel, J. Gruber, W. Köppendörfer, H. Kotzlowski, B. Sombach, K. Ennen, B. Streibl, M. Pillsticker, H. Schneider, U. Seidel, Michael Kaufmann, J.-M. Noterdaeme, O. Gruber, O. Jandl, and M. Blaumoser

Subjects
Physics, Tokamak, Nuclear engineering, Divertor, General Engineering, Plasma, Field coil, law.invention, ASDEX Upgrade, law, Electrical equipment, Magnet, Limiter, Atomic physics
Abstract

ASDEX Upgrade is a tokamak experiment with external poloidal field coils that is now under construction at IPP Garching. It can produce elongated single-null (SN), double-null (DN), and limiter (L) configurations. The SN is the reference configuration with asymmetric load distributions in the poloidal field (PF) system and the toroidal field (TF) magnet. Plasma control and stabilization require a rigid passive conductor close to the plasma. The design principles of the coils and support structure are described.

Published
1986
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20. THE TOROIDAL FIELD MAGNET CONCEPT OF ASDEX UPGRADE

Author

O. Jandl, B. Streibl, H. Kollotzek, and E. Springmann

Subjects
Engineering, Tokamak, business.industry, Divertor, Nuclear engineering, Mechanical engineering, Plasma, Radius, law.invention, Conductor, ASDEX Upgrade, law, Electromagnetic coil, Magnet, business
Abstract

ASDEX Upgrade (UG), a divertor tokamak with a minor plasma radius of a=0.5 m and a plasma current of 1.2 to 1.5 MA, is intended to succeed ASDEX. A major target of this experiment is to investigate a reactor-compatible plasma boundary. This requires according to /1/ a toroidal field (B O ) at the plasma centre normalized to the aspect ratio (A) of B o /A ≈ 1.2. The optimum with due allowance for physical requirements and technical constraints of the complete tokamak system was obtained in this case for B o =3.9 T (A=3.25) and a plasma radius of 1.63m. The toroidal field (TF) magnet designed to meet these requirements is presented here. Aspects of its turnover structure such as force transfer, coil housing and access to the plasma vessel are described. The coil concept developed in collaboration with industry is also presented, in particular the conductor concept and the current terminals and water manifold designs. Finally, the results of the cooling and stress analysis are summarized.

Published
1983
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21. THE TECHNICAL CONCEPT OF THE ASDEX UG POLOIDAL FIELD COILS

Author

M. Pillsticker, F. Werner, and H. Kollotzek

Subjects
Quantitative Biology::Biomolecules, Engineering, Toroid, Tokamak, business.industry, Physics::Medical Physics, Electrical engineering, Torus, Plasma, Mechanics, Magnetic flux, law.invention, Physics::Plasma Physics, Electromagnetic coil, law, Magnet, business, Joule heating
Abstract

The ASDEX UG tokamak poloidal field coil system will comprise three ohmic heating coils and three vertical field coils. The ohmic heating coils consist of a highly excited coil in the central bore of the toroidal field magnet and coils outside the toroidal magnet arranged in pairs symmetric to the torus mid-plane. This coil arrangement is expected to generate a magnetic flux swing of about 9.5 Vs for a total discharge time of the plasma of 10s. The vertical field coils can be arranged a) all outside the toroidal magnet system, and b) partially between the toroidal magnet system and the vacuum vessel, likewise in pairs symmetric to the torus midplane.

Published
1983
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22. THE COMPONENTS OF THE ASDEX UPGRADE TOKAMAK SYSTEM AND THE ASSEMBLY

Author

F. Werner, W. Koeppendoerfer, A. Nijsen-Vis, D. Jacobi, G. Gernhardt, A. Wieczorek, A.M. Van Ingen, J. Gruber, B. Sombach, H. Kollotzek, B. Streibl, E. Lackner, S. Schweizer, H. Vernickel, S. Cha, P. Weng, H. Preis, M. Pillsticker, H.T. Klippel, C. Dorn, X. Wang, M. Blaumoser, H. Schneider, and U. Seidel

Subjects
Physics, Tokamak, ASDEX Upgrade, law, Nuclear engineering, law.invention
Published
1989
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23. TECHNICAL FEATURES AND PROGRESS OF ASDEX UPGRADE

Author

O. Gruber, A. Wieczorek, G. Venus, S. Mukherjee, J. Gruber, H. Preis, E. Speth, M. Pillsticker, H. Kollotzek, D. Jacobi, E. Lackner, M. Troppmann, B. Sombach, A. Wesner, J. Neuhauser, K. Lackner, H. Schneider, J. Gernhardt, M. Blaumoser, B. Streibl, T. von Larcher, U. Seidel, H. Vernickel, S. Schweizer, J.-M. Noterdaeme, K. Ennen, W. H. Reese, W. Jacobus, W. Köppendörfer, R. Mathis, and Michael Kaufmann

Subjects
Physics, Nuclear magnetic resonance, Toroid, Tokamak, ASDEX Upgrade, law, Electromagnetic coil, Nuclear engineering, Divertor, Plasma parameter, Poloidal field, Plasma current, law.invention
Abstract

The objective of ASDEX Upgrade is to investigage open poloidal divertor configurations as produced by a reactor-compatible, poloidal field coil system. The accessible poloidal and toroidal fields and hence the plasma current provide a sufficiently large plasma parameter regime to ensure the functioning of the open divertor.

Published
1986
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32. Divertor tokamak operation at high densities on ASDEX Upgrade

Author

R. Schneider, Bastiaan J. Braams, B. Streibl, F. Serra, A. Thoma, R. Chodura, W. Treutterer, H. W. Mueller, E. Speth, H. J. de Blank, G. Schramm, F. Leuterer, M. Schittenhelm, J. Gernhardt, Klaus Hallatschek, R. Lang, R. Merkel, J. Engstler, K. Krieger, A. Bergmann, C.S. Pitcher, M. Markoulaki, D. Schloegl, K. Asmussen, F. Ryter, A. Staebler, W. Suttrop, P. Franzen, F. Braun, G. Pautasso, M. Bessenrodt-Weberpals, Albrecht Herrmann, K. Reinmueller, K. Behler, Q. Yu, M. Weinlich, D. Zasche, V. Rohde, R. Wunderlich, Harald Schneider, E. Pasch, F. Wesner, D. Jacobi, S. Hirsch, H. Salzmann, H. B. Schilling, A. Buhler, K. Büchl, H. Hohenoecker, G. Pereverzev, M. Troppmann, T. Kass, W. Herrmann, W. Poschenrieder, A. G. Peeters, R. Schwoerer, Thomas Zehetbauer, H. Meister, N. Xantopoulus, M. Kakoulidis, U. Wenzel, A. Khutoretski, H. P. Zehrfeld, H. U. Feist, M. Ulrich, G. Herppich, Robert Wolf, H. Kollotzek, P. Varela, M. Niethammer, M. Muenich, S. Deschka, K.-H. Steuer, H. U. Fahrbach, J. Gafert, Peter Lang, M. Alexander, M. Albrecht, J. Hartmann, S. De Pena Hempel, Bruce D. Scott, P. Ignacz, Sibylle Günter, M. Hoek, H. D. Murmann, M. Maraschek, A. Silva, S. Sesnic, J.-M. Noterdaeme, C. Dorn, R. Drube, R. Dux, Martin Laux, Patrick J. McCarthy, K.H. Behringer, D. P. Coster, Wolf-Dieter Schneider, K. F. Mast, G. Neu, J. Schweinzer, J. Roth, K. Borras, K. Lackner, W. Sandmann, O. Gehre, M. Zouhar, A. Kallenbach, G. Fussmann, O. J. W. F. Kardaun, R. Neu, J. Neuhauser, S. Fiedler, Michael Kaufmann, W. Junker, A. Carlson, Marco Brambilla, W. Kraus, O. Gruber, Eberhard Holzhauer, G. Haas, W. Engelhardt, W. Koeppendoerfer, S. Schweizer, B. Heinemann, V. Mertens, Julia Fuchs, D. Meisel, F. Hoenen, G. Becker, F. Hofmeister, R. Riedl, B. Napiontek, M. Sokoll, H. Roehr, L. Lengyel, Gerhard Raupp, N. Karakatsanis, J. Stober, H. Zohm, Hans-Stephan Bosch, G. Kyriakakis, H. Verbeek, B. Kurzan, N. Tsois, L. Cupido, U. Seidel, O. Vollmer, H. Brinkschulte, and H. Wedler

Subjects
Tokamak, Toroid, Materials science, Radiative cooling, business.industry, Divertor, Plasma, Condensed Matter Physics, Ballooning, law.invention, Computational physics, Nuclear magnetic resonance, Nuclear Energy and Engineering, ASDEX Upgrade, Physics::Plasma Physics, law, business, Thermal energy
Abstract

Densities achievable in ASDEX Upgrade discharges are restricted by a disruptive limit in the L-mode caused by an edge-power imbalance which is linking divertor detachment, Marfe formation and the separatrix density. The attainable average densities depend then on the internal particle sources and the core transport and can exceed the empirical Greenwald density. In H-mode an upper density limit is found which represents a non-disruptive H - L back transition, which is preceded by the occurrence of type-III ELMs. Close to the Greenwald limit this H - L transition cannot be avoided at any power flux across the separatrix and - at high external neutral gas fluxes - confinement compared with ITER H-92P scaling degrades even before the back transition. The H-mode operational window is determined by local edge-barrier parameters and their gradients, respectively. The boundaries are represented by the L - H transition-temperature threshold, the ideal ballooning edge-pressure gradient limit, the upper temperature limit for type-III ELMs and an upper H-mode barrier density limitation. The cause for the last limitation is not yet identified; it may be due to resistive ballooning modes or the separatrix density limit. Despite the limited edge densities the Greenwald density could be surpassed by a factor of three with pellet refuelling from the low magnetic-field side. Pellet injection from the high-field side gains from the strong increase of fuelling efficiency due to the assisting toroidal outward drift of the formed high- ablatant. Higher densities are achievable in H-mode compared with low-field side injection and diminished convective losses avoid confinement degradation up to the Greenwald density. In gas-puffed type-I ELMy H-modes the plasma thermal energy and the edge-pressure gradients, which are limited by ballooning stability, are linked via a robust temperature-profile stiffness and the flat density profiles resulting from dominant edge refuelling at high densities. Their confinement does not improve with increasing density (and neutral gas fluxes) and may even slightly degrade. Therefore, the superior confinement of type-I ELMy H-modes compared with type-III ELMy ones at medium densities is actually offset at densities close to the Greenwald density. In contrast to the temperature-profile resilience density profiles can be changed both by deep refuelling (with pellets) and intrinsic transport improvements connected with density peaking (observed in CDH-modes), which offers the combination of high confinement and high density operation. The possible alliance with radiation cooling, divertor detachment and divertor compatible type-III ELMs could solve the power exhaust problem.

33. Steady state advanced scenarios at ASDEX Upgrade

Author

Michael Kaufmann, H. D. Murmann, Thomas Zehetbauer, Dirk Hartmann, Marco Brambilla, W. Kraus, J. Neuhauser, S. Riondato, H. Maier, J. Gafert, F. Leuterer, D. Merkl, A. Lorenz, J. Gernhardt, R. Riedl, J.-M. Noterdaeme, H. W. Müller, Philipp Lauber, Julia Fuchs, W. Becker, A. Bergmann, Gerhard Raupp, Ana Elisa Bauer de Camargo Silva, F. Ryter, J. Stober, A. C. C. Sips, H. Zohm, D. Meisel, O. J. W. F. Kardaun, K. K. Kirov, R. Kochergov, C. F. Maggi, P. Franzen, D. Wagner, S. D. Pinches, Wolf-Dieter Schneider, A. Lohs, Alexander Kendl, G. Pautasso, H. Kollotzek, V. Rohde, R. Arslanbekov, U. Wenzel, K. Krieger, Martin Jakobi, W. Treutterer, Sibylle Günter, A. Gude, T. Ribeiro, G. Neu, F. Hofmeister, Frank Jenko, T. Eich, F. Wesner, G. Gantenbein, Bastiaan J. Braams, W. Suttrop, Peter Lang, S. Schade, E. Strumberger, H. P. Zehrfeld, G. V. Pereverzev, L. D. Horton, K. Engelhardt, Patrick J. McCarthy, O. Vollmer, F. Braun, K. Mank, S.M. Egorov, M. Münich, S. Saarelma, A. Tabasso, M. Foley, Robert Wolf, G. Becker, C. Sihler, O. Gruber, K.-H. Steuer, A. G. Peeters, S. Schweizer, K.H. Behringer, R. Bilato, Bruce D. Scott, Helmut Faugel, E. Wolfrum, M. Troppmann, Q. Yu, A. Keller, S. Sesnic, Martin Laux, G. Haas, R. Drube, A. Mück, E. Speth, R. Dux, D. P. Coster, O. Gehre, C. Tichmann, E. Quigley, B. Kurzan, J. Hobirk, J. Roth, R. Merkel, D. Bolshukhin, K. F. Mast, H.-U. Fahrbach, Bernd Heinemann, M. E. Manso, H. Hohenöcker, A. Stäbler, Emanuele Poli, H. B. Schilling, V. Mertens, F. Monaco, P. Varela, U. Seidel, A. Buhler, C. Atanasiu, Fernando Meo, B. Heger, K. B. Fournier, V. Igochine, M. Proschek, M. Maraschek, D. Jacobi, W. Sandmann, A. Kallenbach, A. Geier, G. Tardini, R. Neu, G. Schramm, K. Borrass, K. Behler, A. Tanga, D. Zasche, Y.-S. Na, Ursel Fantz, F. Serra, I. Nunes, H. Meister, B. Streibl, Junghee Kim, R. Pugno, Albrecht Herrmann, Garrard Conway, and E. Würsching

Subjects
Materials science, Tokamak, Divertor, Magnetic confinement fusion, Condensed Matter Physics, Electron cyclotron resonance, Neutral beam injection, law.invention, Bootstrap current, Nuclear Energy and Engineering, ASDEX Upgrade, law, Atomic physics, Edge-localized mode
Abstract

Recent experiments at ASDEX Upgrade have achieved advanced scenarios with high β N (>3) and confinement enhancement over ITER98(y, 2) scaling, H H98y2 = 1.1-1.5, in steady state. These discharges have been obtained in a modified divertor configuration for ASDEX Upgrade, allowing operation at higher triangularity, and with a changed neutral beam injection (NBI) system, for a more tangential, off-axis beam deposition. The figure of merit, β N H ITER89-P , reaches up to 7.5 for several seconds in plasmas approaching stationary conditions. These advanced tokamak discharges have low magnetic shear in the centre, with q on-axis near 1, and edge safety factor, q 95 in the range 3.3-4.5. This q-profile is sustained by the bootstrap current, NBI-driven current and fishbone activity in the core. The off-axis heating leads to a strong peaking of the density profile and impurity accumulation in the core. This can be avoided by adding some central heating from ion cyclotron resonance heating or electron cyclotron resonance heating, since the temperature profiles are stiff in this advanced scenario (no internal transport barrier). Using a combination of NBI and gas fuelling line, average densities up to 80-90% of the Greenwald density are achieved, maintaining good confinement. The best integrated results in terms of confinement, stability and ability to operate at high density are obtained in highly shaped configurations, near double null, with δ = 0.43. At the highest densities, a strong reduction of the edge localized mode activity similar to type II activity is observed, providing a steady power load on the divertor, in the range of 6 MW m -2 , despite the high input power used (> 10 MW).

34. Observation of continuous divertor detachment in H-mode discharges in ASDEX upgrade.

Author

Gruber O, Kallenbach A, Kaufmann M, Lackner K, Mertens V V, Neuhauser J, Ryter F, Zohm H, Bessenrodt-Weberpals M, Büchl K, Fiedler S, Field A, Fuchs C, Garcia-Rosales C, Haas G, Herrmann A, Herrmann W, Hirsch S, Köppendörfer W, Lang P, Lieder G, Mast K, Pitcher CS, Schittenhelm M, Stober J, Suttrop W, Troppmann M, Weinlich M, Albrecht M, Alexander M, Asmussen K, Ballico M, Behler K, Behringer K, Bosch HS, Brambilla M, Carlson A, Coster D, Cupido L, DeBlank HJ, De Pena Hempel S, Deschka S, Dorn C, Drube R, Dux R, Eberhagen A, Engelhardt W, Fahrbach H, Feist H, Fieg D, Fu beta mann G, Gehre O, Gernhardt J, Ignacz P, Jüttner B, Junker W, Kass T, Kiemer K, Kollotzek H, Kornherr M, Krieger K, Kurzan B, Lang R, and Laux M

Published
1995
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