Author/Authors :
Wright، نويسنده , , G.M. and Kleyn، نويسنده , , A.W. and Alves، نويسنده , , E. Ivo Alves، نويسنده , , L.C. and Barradas، نويسنده , , N.P. and van Rooij، نويسنده , , G.J. and van Lange، نويسنده , , A.J. and Shumack، نويسنده , , A.E. and Westerhout، نويسنده , , J. and Al، نويسنده , , R.S. and Vijvers، نويسنده , , W.A.J. and de Groot، نويسنده , , B. and van de Pol، نويسنده , , M.J. and van der Meiden، نويسنده , , H.J. and Rapp، نويسنده , , J. and Lopes Cardozo، نويسنده , , N.J.، نويسنده ,
Abstract :
Tungsten targets are exposed to the plasma conditions expected at the strike point of a detached ITER divertor (∼1024 D/m2s, Te ∼ 2 eV). The surface temperature of the target is ∼1600 K at the center and decreased radially 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 ⩽5 × 1015 D/cm2 as measured by NRA. Thermal desorption spectroscopy (TDS) is used to measure the global D retention. Very low retention with retained fractions ranging from 10−7 to 10−5 Dretained/Dincident were measured with TDS. Both NRA and TDS results show no clear dependence of retention on incident fluence possibly indicating the absence of plasma-driven trap production in W under these conditions.
