Diffusivity of recoil-injected or thermally-doped tritium in aluminum

Bulk diffusion coefficients of both recoil-injected and thermally-doped tritium in aluminum were measured. The temperature dependence of the diffusion coefficients was expressed by D = 2 x 10-3 exp[-42.6 +- 2.5(kJ/mol)/RT] (cm2/s) for the recoil-injected tritium, and D = (9 +- 1) x 10-3 exp[-51.9 +- 2.9(kJ/mol)/RT] (cm2/s) for the thermally-doped tritium. A reasonable agreement between the two sets of results is very contrasted to the results found with UO2 as a host material, in which thermally-doped hydrogen diffusion much faster than recoil tritium by several orders of magnitude. Chemical forms of recoil-injected tritium released on heating were also investigated. Both gaseous and condensable components were released. The majority of gaseous component was found as HT, and ca. 2% of CH3T and ca. 0.1% of T2 were detected in the radio-gas chromatographic measurements. (orig.)