First wall coating materials for fusion reactors

Because of using low Z coating materials, the conventional first wall construction materials and techniques can be retained and plasma impurity levels can be reduced. The elements Be, B, C, Al, Ti, V and their compounds are selected as low Z coatings. The coating process and the evaluation methods are described. It was found that the addition of ∼ 10 wt% SiC to pyrolytic carbon provided almost complete suppression of chemical sputtering. The 60 tile array of C+SiC alloy-coated graphite performed satisfactorily during the entire exposure history of the Doublet III Tokamak