Irradiation effect of lithium oxide

Lithium oxide is the primary candidate material for the solid blanket of nuclear fusion reactors. The role of the blanket of nuclear fusion reactors is to produce tritium by the reaction of neutrons with lithium, to extract fusion energy as heat by moderating and thermalizing neutrons, and to shield superconducting magnets and others. Therefore, lithium oxide is exposed to neutrons, tritons and helium ions, and gamma ray, and suffers remarkable irradiation damage. This irradiation damage causes swelling and powdering, the promotion of tritium diffusion and the trapping of tritium, and exerts influence on tritium emission and the compatibility with structural materials. The research on the irradiation damage of lithium oxide is very important for the development of nuclear fusion reactors. In this research, in order to obtain the basic knowledge on the irradiation damage of lithium oxide, the irradiation damage in the lithium oxide irradiated with a reactor and a heavy ion accelerator was observed by electron spin resonance method and light absorption method. The experiment using the sintered piece and single crystal of lithium oxide and the results are reported. (Kako, I.)