George Apostolopoulos is a senior researcher at the Institute of Nuclear & Radiological Sciences & Technology, Energy & Safety of NCSR “Demokritos” and a member of the Fusion Technology Group of NCSR “Demokritos”. His current research work focuses on radiation damage of fusion technology materials. He combines ion beam irradiations with in situ characterization techniques to study fundamental processes of radiation defects in Fe-Cr alloys and other structural materials.
One of the most difficult challenges for the successful realization of future fusion power plants is the development of structural materials capable of withstanding the intense flux of high energy neutrons from the burning plasma reactions. Energetic neutrons have sufficient kinetic energy to displace a large number of atoms from their lattice positions creating extended defects associated with missing atoms (vacancies) and atoms residing in interstitial positions (interstitials). The accumulation of radiation defects during service can lead to a deterioration of crucial macroscopic physical properties such as density, thermal and electrical conductivity and mechanical behaviour. This talk will give an overview of the most important defect processes in advanced structural materials for fusion and the strategies to mitigate their damaging effects. The methods utilized currently for the study of defects including the targeted generation of defects as well as novel techniques employed for their characterization down to the atomic scale will also be described.