|About this Abstract
||MS&T23: Materials Science & Technology
||Advanced Characterization of Materials for Nuclear, Radiation, and Extreme Environments IV
||STEM-based Mapping of Nanoscale Point Defects Produced via Temperature, Irradiation, And Corrosion
||Sean H. Mills, Steven Zeltmann, Peter Ercius, Aaron Kohnert, Blas Uberuaga, Andrew Minor
|On-Site Speaker (Planned)
||Sean H. Mills
Structural metals used in nuclear reactor environments are exposed to coupled extremes such as high temperature, irradiation, and corrosion which act synergistically to degrade material performance. These processes are directly limited or accelerated by nanoscale point defects such as vacancies, interstitials, and voids. Quantifiable methods of elucidating formation of point defects and their role in diffusion kinetics and material failure, have been limited to bulk or ex-situ measurements. Development of 4D-STEM via high-speed direct electron detectors provides opportunities to map distributions of nanoscale features. Here, we explore model metal systems by measuring point defects (with 4D-STEM) produced under equilibrium conditions (thermal cycling), and non-equilibrium conditions such as knock-on electron beam damage, proton irradiation, and molten salt corrosion. Measurements of irradiation and corrosion defects at high spatial resolution advances our understanding of complex molten salt reactor environments, thereby providing a pathway for engineering materials designed in future nuclear energy systems.