(OV/2-2) Overview of ASDEX Upgrade Results

O. Gruber1), C. Angioni1), C.V. Atanasiu2), M. Balden1), G. Becker1), W. Becker1), K. Behler1), K. Behringer1), A. Bergmann1), T. Bertoncelli1), R. Bilato1), V. Bobkov1), T. Bolzonella3), A. Bottino1), M. Brambilla1), F. Braun1), A. Buhler1), A. Chankin1), G. Conway1), D.P. Coster1), T. Dannert1), S. Dietrich1), K. Dimova1), R. Drube1), R. Dux1), T. Eich1), K. Engelhardt1), H.-U. Fahrbach1), U. Fantz1), L. Fattorini4), R. Fischer1), A. Flaws1), M. Foley5), C. Forest6), P. Franzen1), J.C. Fuchs1), K. Gál7), G. Gantenbein8), M. García Muñoz1), L. Giannone1), S. Gori1), S. da Graça1), H. Greuner1), S. Günter1), G. Haas1), J. Harhausen1), B. Heinemann1), A. Herrmann1), J. Hobirk1), D. Holtum1), L. Horton1), M. Huart1), V. Igochine1), A. Jacchia9), F. Jenko1), A. Kallenbach1), S. Kálvin7), O. Kardaun1), M. Kaufmann1), M. Kick1), G. Koscis7), H. Kollotzek1), C. Konz1), K. Krieger1), H. Kroiss1), T. Kubach8), T. Kurki-Suonio10), B. Kurzan1), K. Lackner1), P.T. Lang1), P. Lauber1), M. Laux1), F. Leuterer1), J. Likonen11), A. Lohs1), A. Lyssoivan12), C. Maggi1), H. Maier1), K. Mank1), A. Manini1), M.-E. Manso4), P. Mantica9), M. Maraschek1), P. Martin3), M. Mayer1), P. McCarthy5), H. Meister1), F. Meo13), P. Merkel1), R. Merkel1), V. Mertens1), F. Merz1), H. Meyer14), F. Monaco1), H.-W. Müller1), M. Münich1), H. Murmann1), Y.-S. Na1), G. Neu1), R. Neu1), J. Neuhauser1), J.-M. Noterdaeme1), M. Pacco-Düchs1), G. Pautasso1), A.G. Peeters1), G. Pereverzev1), S. Pinches1), E. Poli1), M. Püschel1), T. Pütterich1), R. Pugno1), E. Quigley5), I. Radivojevic1), G. Raupp1), M. Reich1), T. Ribeiro4), R. Riedl1), V. Rohde1), J. Roth1), M. Rott1), F. Ryter1), W. Sandmann1), J. Santos4), K. Sassenberg5), G. Schall1), H.-B. Schilling1), J. Schirmer1), A. Schmid1), W. Schneider1), G. Schramm1), W. Schustereder15), J. Schweinzer1), S. Schweizer1), B. Scott1), U. Seidel1), M. Serbu1), F. Serra4), Y. Shi16), A. Silva4), A.C.C. Sips1), E. Speth1), A. Stäbler1), K.-H. Steuer1), J. Stober1), B. Streibl1), D. Strintzi1), E. Strumberger1), W. Suttrop1), G. Tardini1), C. Tichmann1), W. Treutterer1), C. Tröster1), M. Tsalas17), L. Urso1), E. Vainonen-Ahlgren11), P. Varela4), L. Vermare1), D. Wagner1), M. Wischmeier1), E. Wolfrum1), E. Würsching1), Q. Yu1), D. Zasche1), T. Zehetbauer1), M. Zilker1), H. Zohm1
 
1) Max-Planck-Institut für Plasmaphysik, EURATOM Association-IPP, 85748 Garching, Germany
2) Institute of Atomic Physics, EURATOM Association-MEdC Romania
3) Consorzio RFX, EURATOM Association-ENEA, Padova, Italy
4) CFN, EURATOM Association-IST Lisbon, Portugal
5) Physics Dep., University College Cork, Association EURATOM-DCU, Ireland
6) University of Wisconsin, Madison, USA
7) KFKI, EURATOM Association-HAS, Budapest, Hungary
8) Institut für Plasmaforschung, Stuttgart University, Germany
9) IFP Milano, EURATOM Association-ENEA, Italy
10) HUT, EURATOM Association-Tekes, Helsinki, Finland
11) VTT, EURATOM Association-Tekes, Espoo, Finland
12) LPP-ERM/KMS, EURATOM Association-Belgian State, Brussels, Belgium
13) NL Riso, EURATOM Association-RISØ, Roskilde, Denmark
14) UKAEA Culham, EURATOM Association-UKAEA, United Kingdom
15) University of Innsbruck, EURATOM Association-ÖAW, Austria
16 IPP, CAS, Hefei, China
17) NCSR Demokritos, EURATOM Association-HELLAS, Athens, Greece

Abstract.  The programme of ASDEX Upgrade, a divertor tokamak with an ITER-like plasma and coil configuration, supports the physics base for ITER operation in both the foreseen standard scenario as well as scenarii with improved performance (improved H-mode, non-inductive current drive). Moreover, physics issues with impact beyond ITER are already identified and addressed. The highlights of the recent progress are presented. For anomalous transport (energy, hydrogen, impurities) a multi-faceted picture of mode dominance in different plasma parameter regimes of ITG, TEM and ETG turbulence was developed including collisions. The active control of MHD instabilities (sawteeth, NTMs) concentrates on ECCD as proposed for ITER. NTMs were completely stabilized with very localized deposition of dc ECCD, while for deposition widths larger than the marginal island size modulated injection phased with the island O-point was demonstrated to be advantageous. The structure and dynamics of natural and pellet induced, mitigated type I ELMs are similar starting from field-aligned helical structures and developing to outward drifting filaments. A small, high-frequency ``grassy" ELM regime is compared to the type II regime. Also in view of ITER, our versatile heating system allows to decouple the effects of bulk plasma and fast ion population. For the first time it was possible to identify directly the phase correlation of fast ions losses with MHD activity (TAEs, NTMs, ELMs). The coverage of the vessel interior with tungsten was further extended up to 85%, where the highest erosion occurs at the LFS poloidal limiters and is dominated by fast particles from NBI as well as impurities accelerated by ICRF. The W concentration could usually be kept acceptable low using ELM pace-making (pellets) and tailored central electron heating. The stationary improved H-mode, discovered at ASDEX Upgrade in 1998, is best suited for a ITER hybrid scenario and could extend ITER operation beyond its standard H-mode performance. It promises either higher fusion performance (Q > 30 at full current) or longer pulses of up to 1 hr at reduced current. The operational range of this regime extends from ITER collisionalities up to high, divertor relevant edge densities. Besides peaked density profiles enhanced edge pressure gradients and consequently higher pedestal top pressures contribute to confinement improvement.

Full paper and slides available (PDF)