Production Behavior and Its Modeling of Irradiation Defects in Lithium Oxide Under Ion Beam Irradiation

The production behavior of irradiation defects in lithium oxide was studied by in-situ luminescence measurement under He⁺ beam irradiation. The luminescence peaks of 380 nm and 340 nm, which were associated with the production of F⁺ and F⁰ centers, respectively, were measured under various conditions such as temperature changes, and the production mechanism and kinetics of these irradiation defects were determined. The F⁺ centers are rather directly produced from Li₂O with the partners of O^- interstitials under Coulomb interactions while the F⁰ centers are produced with O₂ through some diffusion processes. Although the F⁺ production dominates at lower temperatures, the F⁰ production increases with increasing temperature. The F⁰ centers would play an important role in the tritium recovery from ceramic breeder materials at actual blanket conditions.