Thermal cycling tests of plasma facing components for fusion experimental reactors at JAERI

Recent results of R&D on plasma facing components for fusion experimental reactors such as the ITER/FER (International Thermonuclear Experimental Reactor/Fusion Experimental Reactor) are presented. Plasma facing components will be exposed to severe heat loads. Thermal cycling tests for first wall mock-ups and divertor mock-ups have been carried out under specified heat flux conditions of ITER/FER in high heat flux test facilities at JAERI. Tests at a stationary heat flux of 0.2 MW/m ² for first wall mock-ups, exposed in the normal heat flux part, have confirmed their durabilities and reliabilities against the cyclic heat loads. In experiments at a stationary heat flux of 0.6 MW/m ², with exposure also in the high heat flux part, only the radiatively cooled first wall mock-up was tested. A ceramic sleeve covered with pure titanium between the armor and the cooling structure was damaged before reaching a stationary heat flux of 0.6 MW/m² . The authors have also confirmed the integrity and the durability of the bonds in the thermal cycling test of brazed carbon-fiber-composite/copper divertor mock-ups at a simulated stationary surface heat flux of 10 MW/m² for 1000 cycles