Pellet refuelling of particle loss due to ELM mitigation with RMPs in the ASDEX Upgrade tokamak at low collisionality
/ Authors
M. Valovic, P. Lang, A. Kirk, W. Suttrop, M. Cavedon, G. Cseh, M. Dunne, L. Fischer, L. Garzotti, L. Guimarais
and 9 more authors
G. Kocsis, A. Mlynek, B. Plőckl, R. Scannell, T. Szepesi, G. Tardini, A. Thornton, E. Viezzer, E. Wolfrum
/ Abstract
The complete refuelling of the plasma density loss (pump-out) caused by mitigation of edge localised modes (ELMs) is demonstrated on the ASDEX Upgrade tokamak. The plasma is refuelled by injection of frozen deuterium pellets and ELMs are mitigated by external resonant magnetic perturbations (RMPs). In this experiment relevant dimensionless parameters, such as relative pellet size, relative RMP amplitude and pedestal collisionality are kept at the ITER like values. Refuelling of density pump out of the size of Δn/n∼30% requires a factor of two increase of nominal fuelling rate. Energy confinement and pedestal temperatures are not restored to pre-RMP values by pellet refuelling.
Journal: Nuclear Fusion