SPECTROSCOPIC STUDY OF LITHIUM-OXIDE IRRADIATED BY FAST-NEUTRONS

Lithium oxide (Li2O) is a candidate material for solid breeder blanket s in d-t fusion reactors. Radiation damage in Li2O was investigated in IEA BEATRIX-II phase 1 irradiation tests using the Fast Flux Test Fac ility (FFTF). Li2O single crystal specimens with various Li-6 concentr ations, Li-6/(Li-6 + Li-7), were irradiated at about 650 K for 300 eff ective full power days in FFTF by fast neutrons (the fast neutron flue nce (> 0.1 MeV): 3.9 x 10(26) n/m(2)). After the neutron-irradiation, measurements of electron-spin resonance (ESR) and optical absorption w ere carried out for the specimens at room temperature. From the measur ements, colloidal lithium metal was found to be formed in Li2O irradia ted with fast neutrons.