Comparison of the deuterium permeability of copper, CuCrZr, and Cu layers

In order to estimate the fuel loss in ITER and further future fusion devices, the deuterium permeation through different wall and structural materials are studied. In order to determine the effective permeability, gas-driven deuterium permeation measurements are performed on Cu and ITER grade CuCrZr. The obtained permeabilites for Cu and ITER grade CuCrZr are very similar and in agreement to literature values for Cu. For a better estimation for fusion reactor components, combined material samples are studied. Cu layers were applied on steel substrates by magnetron sputter deposition. With these studies, the influence of interfaces and microstructure on the hydrogen permeation is investigated. Our study reveals that in the case of Cu layered steel substrates the influence of the interface on the permeation flux is minor compared to the influence of the microstructure on the permeability. The Cu layer permeability is around one order of magnitude smaller than the Cu bulk permeability in the temperature range between 300∘C and 550∘C.