High heat flux test of CVD-tungsten coated Cu heat sink divertor mock-up

CVD-tungsten coated divertor mock-ups were fabricated and tested in an ion beam test facility in JAERI. The mock-up consisted of a 2 mm thick CVD-tungsten on a 30 wt% Cu infiltrated tungsten skeleton heat sink, For the thermal fatigue tests, the heat load of 15 MW/m(2), 0.3 s was applied to simulate the bonding interface temperature under a steady heat load of 5 MW/m(2). The mock-up successfully endured a heat load of 15 MW/m(2), 0.3 s for more than 1000 thermal cycles. No cracks were observed at the bonding interface by optical microscope observation. Screening tests were also performed to evaluate the performance limit of the mock-up. The mock-up endured up to a heat load of 20 MW/m(2), 10 s without failure.