Hydrogenic retention in tungsten exposed to ITER divertor relevant plasma flux densities

Tungsten targets are exposed to the plasma conditions expected at the strike point of a detached ITER divertor (similar to 10(24) D/m(2)s, Te similar to 2 eV). The surface temperature of the target is similar to 1600 K at the center and decreased radially to similar to 1000 K at the edges. A 2-D spatial scan of the W target using nuclear reaction analysis (NRA) shows an asymmetric D retention profile with the lowest retention values at the center of the target and the highest 6 mm off-center. Even in the regions of larger retention, the D concentrations were