Migration behavior of lithium ions and tritium in Li2O

Li2O is a candidate as solid breeders for D-T fusion reactors. Diffusion of lithium ions and tritium is an important property of materials being considered as the solid breeders. Ionic conductivity of Li2O reflects the lithium-ion diffusion, and the tritium diffusion in Li2O is considered to be closely related to the lithium-ion diffusion from some experimental results. The radiation effects on migration behavior of lithium ions and tritium in Li2O, and the correlation between the radiation effects and the irradiation defects, such as F+ centers, have been investigated by measuring the ionic conductivity of irradiated Li2O. In addition, sites of tritium in the Li2O crystal lattice and the tritium migration mechanisms were studied by computer simulation using the intermediate neglect of differential overlap (INDO) MO LCAO calculation and the embedded molecular cluster model. The calculated results provide validity in theoretical aspect for the evaluation of tritium migration behavior using the ionic conductivity measurements. In this paper, the results in the above-mentioned studies on ionic conductivity of Li2O and the computer simulation study are reviewed. ((orig.))