O2 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 remove the films. In the present study, we have investigated the effect of baking in O-2 on graphite tile substrate materials. After baking five types of graphite in 2.1 kPa O-2 for 100 h at 623 K, no change in mass was observed. 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 erosion rates as high as 10(-5) C/O-2. (C) 2001 Elsevier Science B.V. All rights reserved.