Publications in Scientific Journals:
E. Viezzer, M. Cavedon, E. Fable, F. Laggner, R. McDermott, J. Galdon-Quiroga, M. Dunne, A. Kappatou, C. Angioni, P. Cano-Megias, D. Cruz-Zabala, R. Dux, T. Pütterich, F. Ryter, E. Wolfrum, . ASDEX Upgrade Team, -. EUROfusion MST1 Team:
"Ion heat transport dynamics during edge localized mode cycles at ASDEX Upgrade";
The edge ion heat transport is analyzed in ASDEX Upgrade (AUG) by combining a
comprehensive set of pedestal measurements with both interpretive and predictive modelling.
The experimentally determined ion heat diffusivities, χi, are compared with neoclassical
theory and the impact of edge localized modes (ELMs) on the edge ion heat transport level
is studied in detail. Pedestal matching experiments in deuterium and hydrogen plasmas show
that the inter-ELM pedestal χi remains close to the neoclassical value. The additional power
needed in hydrogen to get similar pedestal temperatures as in deuterium plasmas mostly
affects the electron heat channel, i.e. the electron heat diffusivity increases while the ion heat
diffusivity stays at the same level within the uncertainties. Sub-ms measurements of the edge
ion temperature allows us to extend the analysis to the entire ELM cycle. During the ELM
crash, the ion heat transport is increased by an order of magnitude. The perturbed heat flux
increases first at the separatrix, i.e. first the separatrix ion temperature increases, leading to a
flatter ion temperature gradient, followed by a decrease of the whole pedestal profile. The ion
heat transport returns to its pre-ELM neoclassical level 3-4 ms after the ELM crash.
magnetic confinement fusion, tokamak, plasma transport, magnetohydrodynamics
Created from the Publication Database of the Vienna University of Technology.