Helium-cooled divertor for DEMO: Manufacture and high heat flux tests of tungsten-based mock-ups

Abstract A helium-cooled divertor concept for DEMO has been investigated extensively at the Forschungszentrum Karlsruhe under the EU power plant conceptual study, the goal being to demonstrate performance under heat flux of 10 MW/m 2 at least. Work covers different areas ranging from conceptual design to analysis, materials and fabrication issues to experiments. Meanwhile, the He-cooled modular divertor concept with jet cooling (HEMJ) has been proposed as reference design. In cooperation with the Efremov Institute, manufacture and high heat flux testing of divertor elements was performed for design verification and proof-of-principle. This paper focuses on the technological study of the fabrication of mock-ups from W/W alloy and Eurofer steel supporting structure material. The high heat flux test results of 2006 and 2007 are summarised and discussed.