Assessment of Structural and Silica Materials under Irradiation in Inertial Fusion Reactors: Comparison of Multiscale Modeling and Microscopy

摘要

Materials is a key component in development of Inertial Fusion (IFE) Power Plants; that is a general sentence in most Fusion Research Programs which is very much true. Long term research in Reduced Activation Ferritic Alloys (RAFM) is being pursued in Fusion Programs. A large enough lifetime for such material under irradiation has been estimated which is comparable with that assumed for IFE Reactors operation time. However, comprehension of basic mechanisms of radiation damage is not fully understood to obtain predictive consequences. Multiscale simulation is compared with microscopic experiments using simple material (Fe) that represents steels (Fe) and a preliminary comparison will be presented. Silica is one of the materials candidate for final focusing mirrors in inertial fusion reactors, and it can be exposed to neutron irradiation during operation. Radiation damage results in point defects that can lead to obscuration (degradation of the optical properties of this material). Threshold displacement energies of silica have been calculated using Molecular Dynamics. This study has been performed simulating recoil energies in steps of 5 eV starting with 20 eV. The oxygen deficient centers (defects already known) generated during irradiation are diagnosed because they are able to convert into E' centers responsible of undesired effects. Moreover, defects still not recognized will be searched and their role in the potential degradation under neutron irradiation assessed. Research in SiC-based composites is being developed under a macroscopic perspective. However, results from theory and simulation to explain such physics is being slowly progressing. Systematic identification of stable defects in SiC after irradiation is being developed using a new tight binding molecular dynamics model presently well verified.