Current ramps in tokamaks; From present experiments to ITER scenarios

Imbeaux, F.*; Basiuk, V.*; Budny, R.*; Casper, T.*; Citrin, J.*; Fereira, J.*; Fukuyama, Atsushi*; Garcia, J.*; Gribov, Y. V.*; Hayashi, Nobuhiko; Hobirk, J.*; Hogeweij, D.*; Honda, Mitsuru; Hutchinson, I.*; Jackson, G.*; Kavin, A. A.*; Kessel, C. E.*; Khayrutdinov, R. R.*; Kchl, F.*; Labate, C.*; Leonov, V. M.*; Litaudon, X.*; Lomas, P. J.*; Lnnroth, J.*; Luce, T.*; Lukash, V. E.*; Mattei, M.*; Mikkelsen, D. R.*; Miyamoto, Seiji; Nakamura, Yukiharu*; Nunes, I.*; Parail, V.*; Pereverzev, G. V.*; Peysson, Y.*; Polevoi, A.*; Politzer, P.*; Schneider, M.*; Sips, G.*; Tardini, G.*; Voitsekhovitch, I.*; Wolfe, S. M.*; Zhogolev, V. E.*; ASDEX Upgrade Team*; C-Mod Team*; DIII-D Team*; JET-EFDA Contributors*; JT-60U Team; Tore Supra Teams*; Contributors of the EU-ITM ITER Scenario Modelling Group*; ITPA "Integrated Operation Scenarios" Group*; ITPA "Transport and Confinement" Group*

In order to prepare adequate current ramp-up and ramp-down scenarios for ITER, present experiments from several tokamaks have been analyzed by means of integrated modeling in view of determining relevant heat transport models for these operation phases. The results of these studies are presented and projections to ITER current ramp-up and ramp-down scenarios are done, focusing on the baseline inductive scenario (main heating plateau current of 15 MA). Various transport models have been tested by means of integrated modeling against experimental data from ASDEX Upgrade, C-Mod, DIII-D, JET and Tore Supra, including both Ohmic plasmas and discharges with additional heating/current drive. With using the most successful models, projections to the ITER current ramp-up and ramp-down phases are carried out. Though significant differences between models appear on the electron temperature prediction, the final q-profiles reached in the simulation are rather close.