Plasma operation in a divertor tokamak with all tungsten plasma facing components

To investigate plasma wall interaction with tungsten plasma facing components and its implications in a divertor tokamak, ASDEX Upgrade has been completely equipped with W coated tiles. A range of tools has been developed to allow for discharges with good confinement combined with acceptable W concentrations. After the implementation of W ICRH- and guard-limiters, they were identified as the main W sources during operation of ICRH. This is attributed to the acceleration of intrinsic impurities in the rectified parasitic electrical field leading to an increased W sputtering yield. During the last vent deposited layers were removed from the W surfaces and the start-up of the 2007 campaign was performed without prior boronization. Although all primary carbon sources are removed, almost no reduction of the C concentrations is observed up to now. H-Modes with $H \approx 1$ and a moderate W content could be obtained soon after the first pulse with auxiliary heating and detailed investigations on the W influxes and their impact were performed.