| About this Abstract |
| Meeting |
MS&T22: Materials Science & Technology
|
| Symposium
|
Advanced Characterization of Materials for Nuclear, Radiation, and Extreme Environments III
|
| Presentation Title |
Dose Rate Dependent Radiation Enhanced Diffusion in Model Oxides |
| Author(s) |
Kayla Yano, Aaron Kohnert, Tiffany C Kaspar, Sandra Taylor, Hyosim Kim, Yongqiang Wang, Daniel Schreiber |
| On-Site Speaker (Planned) |
Kayla Yano |
| Abstract Scope |
Oxidation and corrosion of structural alloys in reactors is oftentimes dictated by atomic transport across oxide films formed naturally on alloy surfaces that separate alloys from the environment. Irradiation can dramatically affect this interaction by generating non-equilibrium point defect populations that fundamentally alter transport. However, the direct impact of irradiation on ion transport is broadly unexplored. Here, embedded isotopic tracers (18O and 57Fe) are used to monitor and quantify atomic transport in model irradiated oxide systems with atom probe tomography. Samples are Ar2+ irradiated at varying dose rate and temperature. Combining these observations with a chemical-rate theory model provides insights on fundamental transport mechanisms. These results show orders of magnitude increases in diffusivity over Arrhenius extrapolations. Diffusivities are highly dependent on dose rate and cation and anion diffusivity is similar across irradiation conditions. These results highlight the need for greater understanding of atomistic transport in materials used in reactor environments. |