Detrapping behavior of tritium trapped via hot atom chemical process in neutron-irradiated ternary lithium oxides

Tritium detrapping behavior in neutron-irradiated ternary lithium oxides was investigated by the comparison of the annihilation of irradiation defects with the tritium release. It was revealed that the annihilation of irradiation defects would consist of two processes; namely the fast and the slow ones. The slow annihilation process has correlation with the tritium release, indicating that E′-center or F+-center could act as tritium trapping site, and from its activation energy of each sample, the annihilation of E′-center and F+-center could be attributed to the recovery of oxygen via diffusion, triggering the tritium release. Meyer–Neldel plots of these results indicate that the slow annihilation process was governed by the formation entropy of a pair of vacancy and interstitial atom of oxygen. Therefore, the trapped tritium would be detrapped by oxygen recovery to E′-center or F+-center, and its kinetics would be determined by the population of oxygen vacancy under thermal equilibrium.