CHARACTERISTICS OF MICROSTRUCTURAL EVOLUTION OF RADIATION-DAMAGE IN CERAMICS UNDER FUSION ENVIRONMENT

Ceramics undergo radiation damage via the processes of direct atomic displacement and electronic excitation. The microstructural evolution of radiation damage has been observed with use of electron microscopy during and/or after electron-, ion- and neutron-irradiation. A review is given of our recent progress in understanding the effects of the atomic bonding, the crystal structure, the structural vacancies and the impurities on the characteristics of the microstructural evolution such as defect clusters and amorphization in ceramics. Candidate ceramics for fusion reactors such as MgO, TiC1-x, Al2O3, MgAl2O4, SiC and graphite are classified into four groups in terms of characteristics of dislocation loop kinetics under electron irradiation. Ion- and neutron-induced phenomena in the candidate ceramics as well as non-candidate ceramics are also summarized for the purpose of understanding the microstructural evolution of radiation damage under fusion environment.