Author :
Mertens, V. ; Dux, R. ; Gantenbein, G. ; Gruber, O. ; Günter, S. ; Hobirk, J. ; Horton, L. ; Igochine, V. ; Kallenbach, A. ; Lang, P.T. ; Leuterer, F. ; Maggi, C.F. ; Manini, A. ; Maraschek, M. ; Mück, A. ; Neu, R. ; Noterdaeme, J.M. ; Pautasso, G. ; Sips
Abstract :
ASDEX Upgrade has demonstrated clear progress in ITER relevant plasma operation scenarios. Successful operation with about 70% Tungsten clad first wall is shown. The operation space of the improved H-mode (advanced tokamak scenario) is enlarged in safety factor 3lesq95 les5 and density 0.4lesne/nGWles0.9. The performance can clearly exceed the ITER reference value. At high densities type-II ELMs mitigate the peak power load in the divertor. A similar effect is achieved by increasing the type-I ELM frequency by shallow pellet injection or cyclic vertical plasma motion. Off-axis neutral beam current drive leads at low powers to a clear current density profile modification. Sawtooth tailoring by electron cyclotron current drive (ECCD) can prevent the growth of neoclassical tearing modes (NTM). (3, 2) and (2, 1) NTMs excited at high plasma pressure can be stabilized by ECCD at moderate power levels. Narrow ECCD absorption profiles are more effective than broad ones
Keywords :
Tokamak devices; fusion reactor divertors; fusion reactor limiters; fusion reactor operation; fusion reactor safety; plasma beam injection heating; plasma density; plasma magnetohydrodynamics; plasma pressure; sawtooth instability; ASDEX Upgrade; ITER relevant plasma operation; LFS limiters; core MHD control; current density profile modification; cyclic vertical plasma motion; electron cyclotron current drive; high densities type-II ELMs; high plasma pressure; improved H-mode; moderate power levels; narrow ECCD absorption profiles; neoclassical tearing modes; off-axis neutral beam current drive; peak power load; safety factor; sawtooth tailoring; shallow pellet injection; tokamak divertor operation; tungsten clad first wall; type-I ELM frequency; Absorption; Current density; Cyclotrons; Electrons; Frequency; Plasma density; Safety; Tokamaks; Tungsten; Variable speed drives; ELM triggering; Tokamak divertor operation; Tungsten clad first wall; core MHD control by ECCD; current density profile modification by NBCD; improved H-mode;
