The permeation behavior of T implanted into W was studied by using a pure T ion beam. The T permeation characteristics in the steady and transient states were obtained and were compared with results for D under the same experimental conditions. It was concluded from the steady-state results, for T and D, that the permeation was controlled by diffusion on the implantation side and diffusion on the permeation side. Effective diffusivities were deduced from the permeation behavior of pure T and D. The isotope effect upon the diffusivity of D and T did not agree with classical diffusion theory. The results indicated that the diffusivity of T could be higher than that of D.

Tritium Permeation Study through Tungsten and Nickel using Pure Tritium Ion Beam. H.Nakamura, W.Shu, T.Hayashi, M.Nishi: Journal of Nuclear Materials, 2003, 313-316, 679-84