Author/Authors :
Wright، نويسنده , , G.M. and Al، نويسنده , , R.S. and Alves، نويسنده , , E. Ivo Alves، نويسنده , , L.C. and Barradas، نويسنده , , N.P. and Kleyn، نويسنده , , A.W. and Lopes Cardozo، نويسنده , , N.J. and van der Meiden، نويسنده , , H.J. and Philipps، نويسنده , , V. and van Rooij، نويسنده , , G.J. and Shumack، نويسنده , , A.E. and Vijvers، نويسنده , , W.A.J. and Westerhout، نويسنده , , J. and Zoethout، نويسنده , , E. and Rapp، نويسنده , , J.، نويسنده ,
Abstract :
Tungsten (W) targets have been exposed to high density (ne ⩽ 4 × 1019 m−3), low temperature (Te ⩽ 3 eV) CH4-seeded deuterium (D) plasma in Pilot-PSI. The surface temperature of the target was ∼1220 K at the center and decreased radially to ∼650 K at the edges. Carbon film growth was found to only occur in regions where there was a clear CII emission line, corresponding to regions in the plasma with Te ⩾ 2 eV. The maximum film thickness was ∼2.1 μm after a plasma exposure time of 120 s. 3He nuclear reaction (NRA) analysis and thermal desorption spectroscopy (TDS) determine that the presence of a thin carbon film dominates the hydrogenic retention properties of the W substrate. Thermal desorption spectroscopy analysis shows retention increasing roughly linearly with incident plasma fluence. NRA measures a C/D ratio of ∼0.002 in these films deposited at high surface temperatures.
