Major results of the cooperative program between JAERI and universities using plasma facing materials in JT-60U

The cooperative research program between JAERI and universities using the first wall tiles was initiated in 2001 to elucidate the plasma–wall interactions in JT-60U. Various studies have been intensively performed from 2001 to 2002. Major research results obtained in these years were reviewed. Main topics are as follows: (1) Tritium areal distribution on plasma facing graphite tiles was measured by using tritium imaging plate technique and a combustion method. the results were compared to the simulation results for triton orbits, (2) erosion depth and deposition thickness were measured poloidally by using dial gauge and SEM on a set of W-shaped divertor tiles, (3) distribution of hydrogen isotopes and the chemical status of carbon in the divertor region were evaluated by SIMS and XPS, (4) release behavior of tritium from graphite tile samples was studied using thermal desorption, and (5) tritium degassing characteristics in tokamak exhaust were investigated by cleaning discharges.