Island divertor spectroscopy at the Wendelstein W7-AS stellarator

The island divertor concept, which is regarded as being the natural concept for low shear advanced stellarators like W7-AS and W7-X, has for the first time been put to a realistic test in the present experimental campaign of W7-AS. A large number of diagnostics, specifically geared towards the diagnosis of island divertor plasmas, have been installed in the course of the last two years. This report will introduce some of the newly installed active and passive spectroscopy based divertor diagnostics