We have investigated retention of deuterium in beryllium-containing, laboratory-made films whose properties resemble co-deposits observed on JET-ILW or predicted for ITER. The samples were prepared using High Power Impulse Magnetron Sputtering and Thermo-ionic Vacuum Arc Deposition. We have observed that retention depends on the flux of D atoms on the growing film, but even more prominently on its composition, structure, and morphology. Especially, inclusion of carbon by 10-15 at% in the layers can increase retention by a factor of 2-10. This we attribute to increasing number of defects as well as aromatic and aliphatic C-D bonds in the samples. Other impurities do not significantly alter the D inventory while more D is retained in samples with rough or highly modified surfaces. Our results show that reproducing the reported D concentrations of ∼5 at% in JET-ILW-like deposits requires keeping the sample temperature at 100-200 °C during the production phase and optimizing the uniformity of deposition fluxes. Data from Be-D samples further indicate that fuel retention in more ITER-relevant co-deposits would be around 1-2 at%.
|Publication status||Published - 1 Jan 2020|
|MoE publication type||A1 Journal article-refereed|
|Event||17th International Conference on Plasma-Facing Materials and Components for Fusion Applications, PFMC 2019 - Eindhoven, Netherlands|
Duration: 20 May 2019 → 24 May 2019
- Fuel retention