Simulation of Ion Irradiation of Nuclear Materials and Comparison with Experiment

TL;DR

This study combines simulation and experimental techniques to analyze radiation defect formation in nuclear materials like Mo and CeO2 under ion irradiation, providing insights into defect evolution and validating models with empirical data.

Contribution

It introduces a comprehensive approach integrating TRIM, MD simulations, and TEM experiments to study defect formation and evolution in nuclear materials under irradiation.

Findings

Defect distributions in CeO2 match simulation predictions.

Void and bubble formation rates are estimated with a new mesoscale model.

Experimental results characterize dose and temperature effects on defect structures.

Abstract

Radiation defects generated in various nuclear materials such as Mo and CeO2, used as a surrogate material for UO2, formed by sub-MeV Xe and Kr ion implantations were studied via TRIM and MD codes. Calculated results were compared with defect distributions in CeO2 crystals obtained from experiments by implantation of these ions at the doses of 1\times10^17 ions/cm2 at several temperatures. A combination of in situ TEM (Transmission Electron Microscopy) and ex situ TEM experiments on Mo were used to study the evolution of defect clusters during implantation of Xe and Kr ions at energies of 150-700 keV, depending on the experimental conditions. The simulation and irradiation were performed on thin film single crystal materials. The formation of defects, dislocations, and solid-state precipitates were studied by simulation and compared to experiment. Void and bubble formation rates are estimated based on a new mesoscale approach that combines experiment with the kinetic models validated by atomistic and Ab-initio simulations. Various sets of quantitative experimental results were obtained to characterize the dose and temperature effects of irradiation. These experimental results include size distributions of dislocation loops, voids and gas bubble structures created by irradiation.