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. H.*; 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.*; ASDEX Upgrade Team*; Alcator 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 various tokamaks have been analysed by means of integrated modelling in view of determining relevant heat transport models for these operation phases. The most accurate heat transport models are then applied to projections to ITER current ramp-up, focusing on the baseline inductive scenario (main heating plateau current of Ip = 15 MA). These projections include a sensitivity studies to various assumptions of the simulation. Recent examples of such simulations, involving coupled core transport codes, free boundary equilibrium solvers and a poloidal field (PF) systems controller are described in the second part of the paper, focusing on ITER current ramp-down.