Development of actively cooled divertor plates for fusion experimental devices

Development of high thermal resistant divertor plates using the brazing technique has been conducted. Uni-directional carbon-fiber-reinforced-carbon (CFC) has been selected as the surface material because of its high thermal conductivity and mechanical strength, while copper-alloy has been chosen as the base plate because of its high thermal conductivity. Brazing materials on CFC were examined and applied to the divertor element samples (25mm×25mm×35mm). Then, the samples were exposed to a high heat flux electron beam. It was found that the fabricated samples can withstand repetitive thermal shocks of 30MW/m 2 ×2sec for more than 500 times. Using the developed method, two types of partial divertor models were fabricated and tested. It was shown that the models have sufficient structural integrity against thermal shocks of 9MW/m 2 sec˜14MW/m 2 ×4sec for up to 1200 times. The thermal analyses suggested that the models could withstand the steady-state heat flux of 12.6MW/m 2 . In addition, the thermal stress analyses showed that the structural modification could reduce the thermal stress on the models.