Tritium permeation study through tungsten and nickel using pure tritium ion beam

Permeation behavior of tritium (T) implanted into tungsten and nickel has studied by using pure tritium ion beam. Tritium permeation characteristics of steady and transient states were obtained and were compared with the result of deuterium (D) under the same experimental conditions. It was concluded from the steady state results of T and D that the permeation was controlled by diffusion in implantation side – diffusion in permeation side process for tungsten and recombination at the implantation surface – diffusion in the permeation side process for nickel. Effective diffusivities were evaluated from the permeation behavior of pure T and D. Isotope effect on the diffusivity between D and T did not agree with the classical diffusion theory, but could be explained by a quantum statistical diffusion model for nickel. The results indicated that diffusivity of T could be larger than that of D in W and Ni, respectively.