Berlin 2014 – wissenschaftliches Programm

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P: Fachverband Plasmaphysik

P 16: Helmholtz Graduate School for Plasma Physics I

P 16.1: Fachvortrag

Mittwoch, 19. März 2014, 14:00–14:25, SPA HS202

Transport analysis of high radiation and high density plasmas at ASDEX Upgrade — •L. Casali, M. Bernert, R. Dux, R. Fisher, A. Kallenbach, O. Kardaun, B. Kurzan, P. Lang, A. Mlynek, R. McDermott, F. Ryter, M. Sertoli, G. Tardini, and H. Zohm — Max-Planck-Institut für Plasmaphysik, EURATOM-Assoziation, Boltzmannstraße 2, D-85748 Garching

Future fusion reactors will operate under more demanding conditions compared to present devices. They will require high divertor and core radiation by impurity seeding to reduce heat loads on divertor target plates. In addition, high core densities are required to reach adequate fusion performance. These scenarios are addressed at the ASDEX Upgrade tokamak. Here we present the transport analysis of such scenarios. Plasmas with high radiation by impurity seeding: a non coronal radiation model was developed and compared to the bolometric measurements in order to provide a reliable radiation profile for transport calculations. Power balance analyses taking into account the radiation distribution show no change in the core transport during impurity seeding. High density plasmas with pellets: very good agreement between experimental values and transport calculations is found. Both reveal that τ_E remains constant despite the density increase. Hence the density dependence of ITER98 (τ_E ∼ n_e^0.41) is not adequate to describe this regime. The kinetic profiles reveal a transient phase at the pellet start due to a slower density build up compared to the temperature decrease. The low particle diffusion can explain the confinement behaviour.