TRITIUM IMAGING OF JET WALL TILE EXPOSED TO D-T SHOTS

Tritium imaging was used to determine the lateral distribution of residual tritium in an X-point carbon-carbon composite tile taken from the JET tokamak after the Preliminary Tritium Experiment of November 9, 1991. Substantial variation in image brightness was observed in different parts of the tile. Features of the fine scale morphology that were visible by optical microscopy were also observed in the tritium images. Alternate sputtering and imaging of tile specimens indicates the presence of tritium at depths beyond the implantation range that would be expected under tokamak operating conditions, suggesting that tritium is being codeposited with carbon. The total tritium content of two specimens were assessed by destructive means. Analysis suggests that most of the tritium present in the tile specimens was codeposited during the post-PTE cleanup.