The occurrence of high stress concentrations in reactor components is a still intractable phenomenon encountered in fusion reactor design. We observe and quantitatively model a non-linear high-dose radiation mediated microstructure evolution effect that facilitates fast stress relaxation in the most challenging low-temperature limit. In situ observations of a tensioned tungsten wire exposed to a high-energy ion beam show that internal stress of up to 2 GPa relaxes within minutes, with the extent and time-scale of relaxation accurately predicted by a parameter-free multiscale model informed by atomistic simulations. As opposed to conventional notions of radiation creep, the effect arises from the self-organisation of nanoscale crystal defects, athermally coalescing into extended polarized dislocation networks that compensate and alleviate the external stress.
@article{arxiv.2401.13385,
title = {Fast low-temperature irradiation creep driven by athermal defect dynamics},
author = {Alexander Feichtmayer and Max Boleininger and Johann Riesch and Daniel R. Mason and Luca Reali and Till Höschen and Maximilian Fuhr and Thomas Schwarz-Selinger and Rudolf Neu and Sergei L. Dudarev},
journal= {arXiv preprint arXiv:2401.13385},
year = {2024}
}