Development of the Q = 10 scenario for ITER on ASDEX Upgrade (AUG)

Abstract

The development of the baseline H-mode scenario foreseen for ITER on the ASDEX Upgrade tokamak, i.e. discharges at q95 = 3, relatively low βN ~ 1.8, high normalized density n/nGW ~ 0.85 and high triangularity δ = 0.4, focused on the integration of elements foreseen for ITER and available on ASDEX Upgrade, such as ELM mitigation techniques and impurity seeding in combination with a metallic wall. Values for density and energy confinement simultaneously came close to the requirements of the ITER baseline scenario as long as βN stayed above 2. At lower heating power and thus lower βN normalized energy confinement H98y2 ~ 0.85 is obtained. It has been found that stationary discharges are not easily achieved under these conditions due to the low natural ELM frequency occurring at the low q95/high δ operational point. Up until now the ELM parameters were uncontrollable with the tools developed in other scenarios. Therefore studies on an alternative operational point at higher βN and q95 have been conducted. In order to prepare for the ITER first non-activation operational phase, Helium operation has been investigated as well.