Fusion Science and Technology / Volume 60 / Number 1 / July 2011 / Pages 389-393
Materials Development & Plasma-Material Interactions / Proceedings of the Nineteenth Topical Meeting on the Technology of Fusion Energy (TOFE) (Part 1)
Tritium permeation through erbium oxide coatings has been modeled on the basis of experimental results. Permeation models were constructed step-by-step by the introduction of the following predominant parameters: surface coverage, grain size, and energy barrier. The surface-coverage model agreed with the imperfectly coated samples fabricated by filtered arc deposition as well as by metal-organic decomposition. The grain-boundary-diffusion model also agreed with the coatings fabricated by filtered arc deposition, though it was not applicable to the metal-organic decomposition coatings because of impurities and different layer structures. The energy-barrier model explains the contributions to the additional permeation reduction of the multilayer coatings. The discussion of permeation models provides new design concepts for the development of tritium permeation barriers.