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arXiv · 2401.13385

Fast low-temperature irradiation creep driven by athermal defect dynamics

Alexander Feichtmayer·Max Boleininger·Johann Riesch·Daniel R. Mason·Luca Reali·Till Höschen·Maximilian Fuhr·Thomas Schwarz-Selinger·Rudolf Neu·Sergei L. Dudarev
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Abstract

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.

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Alexander Feichtmayer, Max Boleininger, Johann Riesch, Daniel R. Mason, Luca Reali, Till Höschen, Maximilian Fuhr, Thomas Schwarz-Selinger, Rudolf Neu, Sergei L. Dudarev. 2024-01-24. Fast low-temperature irradiation creep driven by athermal defect dynamics. https://arxiv.org/abs/2401.13385

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