Radiation damage in metals, and amorphous silica in inertial fusion reactors: Modeling and experiments

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A systematic analysis of primary damage will follow for high-energy recoils, in order to get distribution of cascades and subcascades versus recoil energies. Considering Fe, simulations have been performed using new activation energies for diffusion of interstitial defects, and a new random 3D movement has been considered in modeling. New vacancy's migration energies for 3-4 vacancy clusters and last ab-initio diffusion parameters for impurities were also implemented. Results will be compared to experiments, to quantify the defect concentration and the defect type. A new full scale of irradiation experiments of metals and diagnosis including resistivity analysis will also be presented. In addition, the plans to extend such defect dynamics simulation to the scale of defect-dislocation dynamics will be presented. Using defect energetic and cascade damage obtained from molecular dynamics, results will be presented on irradiation of hcp α-Zr under different conditions with a kinetic Monte Carlo model. Cascades of 25 keV will be considered in the evolution of the microstructure during irradiation under environment conditions of 600K, 10 -6 dpa/s and 0.5 dpa. We will present preliminary comparisons with experimental data. Finally, our previous and present results on α-Zr will be extrapolated to Titanium that has very useful applications in nuclear fusion reactors. Defects in silica and carbon may be present in the material, in many cases associated to impurities, or generated by irradiation. A systematic identification of defect types in these materials, depending on its final potential energy and its morphology, calculating the co-ordination and neighbour type will be presented, and their concentration as a function of stoichiometric deviations is studied using classical molecular dynamic. To study the effects of different hydrogen isotopes in silica and their interaction with the defect concentration is considered as an important effect and a modelling analysis will be presented. A full-scale experimental program, using visible and infrared optical spectroscopy, for understanding those mechanisms and validate simulation results will also be presented.