(EX/1-1) The performance of improved H-modes at ASDEX Upgrade and projection to ITER

A.C.C. Sips1), G. Tardini1), C. Forest2), O. Gruber1), P. Mc Carthy3), A. Gude1), L.D. Horton1), V. Igochine1), O. Kardaun1), C.F. Maggi1), M. Maraschek1), V. Mertens1), R. Neu1), A. Peeters1), G.V. Pereverzev1), A. Stäbler1), J. Stober1), W. Suttrop1), ASDEX Upgrade Team1)
1) Max-Planck-Institut fuer Plasmaphysik, Garching, Germany
2 The University of Wisconsin, Madison, USA.
3 Dep. of Physics, University College Cork, Association EURATOM-DCU, Cork, Ireland

Abstract.  At ASDEX Upgrade, stationary discharges with improved confinement ( H98(y, 2) > 1) and improved stability ( β  > 2.5) compared to standard H-mode have been developed since 1998. New results presented here concentrate on extending the operational range of these improved H-modes at ASDEX Upgrade and extrapolating these new results to ITER. The performance is optimised for q95 ranging from 3 to 5, for different values of collisionality, at high edge density, with significant central electron heating and with a first wall predominantly covered by tungsten coated carbon tiles. For the extrapolation to ITER, the fusion gain that could be obtained is evaluated using different confinement scalings, while the ASTRA transport code is used to provide an extrapolation of the fusion power in ITER. These ASDEX Upgrade results indicate that improved H-modes (candidate for a hybrid scenario) could extend ITER operation beyond what is currently foreseen using standard H-modes.

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