Multi-scale modeling of interstitial dislocation loop growth in irradiated materials

In order to reduce the inherent uncertainty in kinetic theory models and promote their transition to become predictive methodologies, a multi-scale modeling approach is proposed and demonstrated in this work. KiValues of key materials properties such as point defect (vacancy and interstitial) migration enthalpies, as well as kinetic factors, such as dimer formation and defect recombination coefficients and self-interstitial atom - interstitial loop reaction rates, were obtained by ab initio/molecular dynamics calculations. A rate theory model was used to interpret the evolution of dislocation loops in irradiated molybdenum. Calculations of the dose dependence of average loop diameter were performed and compared to experimental measurements obtained from irradiations with high-energy electrons. The comparison demonstrates reasonable agreement between model-predicted and experiment-measured data.