ASDEX-Upgrade edge transport scalings from the two-dimensional interpretative code B2.5-I

An interpretative version of the edge plasma code B2-SOLPS5.0 has been developed in order to investigate transport in the tokamak edge. A multi-variable fit procedure is used to minimise the differences between code predictions of plasma quantities and the experimental measurements of these same quantities by varying input parameters to the code (e.g., the radial heat diffusivity, the radial particle diffusivity, the fractional amount of neutrals pumped). A number of ASDEX-Upgrade (AUG) shots have now been analysed, and a preliminary analysis of the resulting database performed. Regression analysis suggests a strong improvement of heat transport with increasing plasma current, and moderate degradation with increasing density and heating power. Separate regressions for hydrogen and deuterium discharges suggest differences in the scalings of the transport. Work has now started on fitting both a diffusivity and an inward pinch for the particle transport.