Abstract Scope |
Primary radiation damage featuring rapid atomic collisions and thermal spikes constitute the foundation of a high-fidelity description of radiation-assisted microstructure evolution. Mixed oxide system Th1-xUxO2 with fluorite structure experiences intense irradiation as nuclear fuels. To systematically describe the primary damage, we consider the effect of temperature, composition, and primary-knock atom energy on defect generation. A holistic functional form is developed to effectively quantify the number of defects, and the exponential truncated power-law can well describe defect cluster size distribution. Finally, the defect (cluster) structures are elaborated, notably that vacancy clusters converge to charge balanced state with increasing size and interstitial clusters can embrace high symmetry. These results provide both a high-level description and a detail atomic understanding towards the radiation-induced defects in fuel oxide, which can serve as input to meso-scale simulations for long time scale and large spatial scale microstructure evolution. |