Spectroscopic Evidence for Flow Reversal at High Density in ASDEX Upgrade Divertor II

For an optimized design of the divertor and its operation in future fusion reactors it is essential to study divertor physics in present-day fusion experiments. In order to increase the reliability of extrapolation to ITER, it is most important to validate numerical plasma edge codes by experimental results. One main feature predicted by theory and modelling for a long time is flow reversal [1]. As this effect might lead to a contamination of the main plasma by impurities it has to be understood in order to find and explore methods of controlling it.