Title :
Recent ASDEX Upgrade Results and Future Extension Plans
Author :
Kallenbach, A. ; Bobkov, V. ; Braun, F. ; Herrmann, A. ; Hohnle, H. ; McDermott, R.M. ; Neu, R. ; Noterdaeme, J. ; Putterich, T. ; Schweinzer, J. ; Stober, J. ; Strumberger, E. ; Suttrop, W. ; Wagner, D. ; Zohm, H.
Author_Institution :
Max-Planck-Inst. fur Plasmaphysik, Assoc. EURATOM, Garching, Germany
fDate :
3/1/2012 12:00:00 AM
Abstract :
ASDEX Upgrade (AUG) is an ITER-shaped divertor tokamak with versatile heating, fueling, exhaust, and control systems. All plasma-facing components (PFCs) are coated with tungsten layers. Plasma scenarios have been adopted that avoid central tungsten accumulation, which can lead to an H-L transition due to excessive central radiative losses. Compared to a carbon-PFC tokamak, the AUG operational space is slightly more weighted toward higher densities and collisionalities. Actual and future planned extensions aim toward reducing the core collisionality while maintaining good power and particle exhaust. These extensions include a solid tungsten outer divertor target, improved pumping, higher ECRH power, and modified ICRF antennas that reduce tungsten sources. The newest element for advanced plasma control is the first set of eight magnetic perturbation coils, which already achieved type-I edge localized mode mitigation in multiple plasma scenarios. Another eight coils have been installed in autumn 2011, allowing the production of mode spectra with n >; 2. In parallel to the improved actuator set, an increasing number of diagnostics are brought into real-time state, allowing versatile profile and stability control.
Keywords :
Tokamak devices; actuators; antennas in plasma; exhaust systems; fusion reactor divertors; localised modes; perturbation theory; plasma collision processes; plasma density; plasma radiofrequency heating; plasma toroidal confinement; tungsten; ASDEX Upgrade; AUG operational space; H-L transition; ITER-shaped divertor tokamak; W; actuator set; collisionalities; control system; excessive central radiative losses; exhaust system; fueling system; future extension plans; higher ECRH power; magnetic perturbation coils; mode spectra; modified ICRF antennas; plasma density; plasma-facing components; pumping; real-time state; solid tungsten outer divertor target; stability control; tungsten layer coating; tungsten sources; type-I edge localized mode mitigation; versatile heating system; versatile profile; Antenna measurements; Antennas; Coils; Heating; Plasmas; Tungsten; Divertor; ECRH; ICRF; fusion devices; plasma-facing components (PFCs); tungsten;
Journal_Title :
Plasma Science, IEEE Transactions on
DOI :
10.1109/TPS.2011.2179068