High heat flux test of actively cooled tungsten-coated carbon divertor mock-ups

CX-2002U and IG-43OU coated by VPS-W were developed to be as a light high-Z plasma-facing material. After brazing them on OFHC blocks using a Ti foil, their thermal response and thermal fatigue properties were examined with active cooling. No cracks and no exfoliation occurred on the W surface and the braze interface even after 160 cycles of heat load for 20 s at 10 MW/m2. This result indicates that the Ti-brazing is a possible alternative to Ag-brazing for joining carbon to Cu. Heat load resistance of the VPS-W coated CX-2002U/OFHC was much better than the VPS-W coated IG-430U/OFHC due to the excellent thermal conductivity of CX-2002U. VPS-W coated CFC/OFHC is a potential candidate for a high heat resistance armor material on plasma facing components.