O-2 erosion of graphite tile substrates

The removal of codeposited tritiated carbon films from the next generation of fusion reactors may rely on the use of baking in an Oz environment to re move the films. In the present study, we have investigated the effect of ba king in O-2 on graphite tile substrate materials. After baking five types o f graphite in 2.1 kPa O-2 for 100 h at 623 K, no change in mass was observe d. An upper limit on the erosion rate was calculated to be similar to4 X 10 (-10) C/O-2, whereas the codeposited films obtained from tokamaks have eros ion rates as high as 10(-5) C/O-2. (C) 2001 Elsevier Science B.V. All right s reserved.