Inferring radiation-induced microstructural evolution in single-crystal niobium through changes in thermal transport

Abstract

Abstract Ion beams enable accelerated radiation exposure experiments, but traditional destructive post-irradiation examination techniques remain time-consuming. Here, measurements of thermal diffusivity are used to monitor microstructural changes in single crystal niobium irradiated with Si3+ ions up to 1.9 dpa (5.1\u202f×\u202f1015 ions/cm2). Changes in thermal transport are correlated to defect generation and clustering through dose-microstructure relationships. These measurements are made using transient grating spectroscopy (TGS), a multi-modal, non-destructive, rapid characterization technique. This work demonstrates that in this low-dose point defect clustering regime, direct measurements of thermal properties are a powerful tool for understanding irradiation-induced microstructure evolution.