Surface distribution of tritium on graphite tiles of divertor area in JT-60U

Tritium distributions on the graphite tiles used as plasma facing tiles in divertor tiles, dome units, and the baffle plates of JT-60U were successfully measured. The highest tritium level was found at the top of the dome or the private region and the outer baffle plates, where the plasma did not hit but the distance from the plasma was the shortest. For the divertor tiles, the tritium retention was very small. Such tritium distribution observed in JT-60U tiles can be well explained by the homogeneous implantation of rather high energy tritium and thermal release due to the heat load.