A 2D approach to island divertor modelling for Wendelstein 7-AS

The properties of an island divertor for Wendelstein 7-AS were investigated by using the B2-Eirene package. Because B2 is a two dimensional code the calculation needs to be done on a toroidally averaged grid. Carbon influx resulting from physical and chemical sputtering was treated self-consistently. The model predicts a transition from low to high recycling at a separatrix density of 1 * 10 m . A detailed discussion of the momentum removal mechanism for this geometry will be presented.