Structural changes and distribution of accumulated tritium in the carbon based JET tiles

In this study the tritium distribution and the effect of structural changes thereon have been analyzed in the bulk of the tile selected from the JET Mark II SRP divertor. Tritium content has been analyzed by the full combustion technique [1]. The structure has been investigated by the method of Scanning Electron Microscopy. Tritium depth profiles have been measured at different poloidal positions. A high specific activity of tritium (up to 156 MBq g ^-1) was found at the plasma-facing surface. At some tile positions up to 98-99% of the T can be in the surface slice of 1 mm thickness, whereas in other poloidal positions there can be more T in the bulk than at the surface. The structural changes of the tile material both at the surfaces and in the bulk have been measured.