Progress in the design and development of a test divertor (TDU) for the start of W7-X operation

With the aim of starting plasma operation in 2014 the Wendelstein 7-X (W7-X) project has developed a scenario with an intermediate operational phase in which a reduced number of in-vessel components are installed prior to going to the fully equipped, full performance phase.An important part of this scenario is the test divertor (TDU), an adiabatically cooled, reduced pulse length device that will allow machine operation over a comparable range of plasma configurations as the final long pulse high-heat flux (HHF) divertor, which will be installed after two years operation of the TDU.The design and development of the TDU has started by clearly defining the requirements of the TDU with regard to performance, material selection, geometry, interfaces to other components, diagnostic integration, installation requirements and tolerances and quality management. In fact, the whole TDU development will follow the procedures laid down for design and development of components within the W7-X project. This paper provides a description of the design and development of the TDU to date.