The focus has been put on D-doped Be-O, Be-W, Be-C-O (in the case of JET-ILW comparison) coatings with different surface morphologies in the nanoscale and thicknesses ranging from about 0.1 um to some 15 um. The relative D content of the samples can routinely be increased to 5-10 at.%, and in some coating types even 40 at.% has been reached. This is a good starting point to fabricate co-deposits with seeding gases and/or helium in the future. The Be-O-C-D coatings most closely resembling the JET-ILW co-deposits (O and C content 5-10 at.%, D content ~5 at.%, thickness ~15 um) show very similar release behavior of D as real JET samples, indicating that the laboratory samples well mimic the structure of co-deposits in fusion reactors.
The surface analyses have revealed that increasing the O content from a few to 50 at.% in otherwise identical samples lowers the amount of D that can be retained, by up to a factor of 10. Implantation with D+ ions results in similar retention behavior, though with more peaked D profiles, than direct doping during the deposition phase. The data also indicate that more D can accumulate in the sample if the thickness of the coating is increased, the surface becomes more modified and rough, or, in the case of mixed Be-W deposits, the relative Be fraction increases.
 K. Heinola et al., Experience on divertor fuel retention after two ITER-Like Wall campaigns, Phys. Scr. (accepted).
|Title of host publication
|23rd PSI Conference Princeton USA
|Subtitle of host publication
|Book of Abstracts
|Number of pages
|Published - Jun 2018
|MoE publication type
|23rd International Conference on Plasma Surface Interactions in Controlled Fusion Devices - Princeton University, Princeton, United States
Duration: 17 Jun 2018 → 22 Jun 2018
|23rd International Conference on Plasma Surface Interactions in Controlled Fusion Devices
|17/06/18 → 22/06/18