Divertor concept for the Wendelstein 7-X stellarator: Theoretical studies of the boundary and engineering

The stellarator Wendelstein 7-X is under construction in Greifswald. For energy and particle exhaust under stationary conditions ten divertor units are arranged along the helical edge of the five-fold symmetric plasma column. In respect of the boundary variations for the investigated magnetic configurations in a first step an ``open'' divertor was chosen. The geometry and the specifications of the in-vessel components reflecting the 3D topology of the boundary are defined in accordance with results of various theoretical studies. The theoretical methods for the characterisation and the proposed technical solutions for the main components - including the instrumentation - target, baffle, wall protection, and control coils will be described.