Deuterium permeation and diffusion in high purity beryllium

The permeation rate of deuterium through high-purity beryllium membranes was measured using the gas-driven permeation technique. The time-dependent and the steady-state deuterium flux data were analyzed and the effective diffusivities of the samples were determined. A multilayer permeation theory was used in order to eliminate the surface oxide effects and the diffusion coefficients of the bulk beryllium were determined. The diffusion parameters obtained for the extra-grade beryllium samples (99.8%) are D0 = 6.7 x 10-9 [m2/s] and ED = 28.4 [KJ/mol]; and for the high-grade beryllium samples (99%) the parameters are D0 = 8.0 x 10-9 [m2/s] and ED = 35.1 [KJ/mol]