Recent results from edge modelling on ASDEX Upgrade

In this paper we cover recent results obtained from modelling the edge plasma of ASDEX Upgrade (AUG): (1) detailed simulations of a few discharges where upstream and target data from the experiment were compared with the code results; (2) detailed simulations of a series of AUG discharges targeted at understanding the processes of divertor detachment; (3) the simulation of an AUG discharge where a transition from L-mode to H-mode was triggered solely by a drop in the toroidal magnetic field; (4) simulations of the penetration of Massive Gas Injection (MGI) gas puffs used for disruption mitigation; (5) simulations to examine the effect of ELM 'size' on the whole plasma. The simulations were performed with the 2d fluid plasma, 3d Monte-Carlo neutrals code B2-Eirene, part of the SOLPS suite of plasma simulation codes. Key results include: (1) a difference between well diagnosed AUG discharges and the modelling possibly pointing to kinetic physics not included in the fluid plasma description; (2) qualitative but not yet fully quantitative agreement between the experiment and modelling results of detachment; (3) modelling of the L- and H-mode phases of an AUG discharge showed a change in the particle transport coefficients but not the energy transport coefficients. (author)