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UKAEA-CCFE-PR(25)3772025
The vacancies and interstitials produced in high-energy collision cascades of irradiated tungsten can form prismatic dislocation loops with Burgers vectors 1⁄2⟨1 1 1⟩ and ⟨1 0 0⟩. The 1⁄2⟨1 1 1⟩ loops are very mobile, and their mobility is essential for the microstructure development of irradiated materials, It is a key parameter …
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UKAEA-CCFE-PR(25)3612025
The change in materials properties subjected to irradiation by highly energetic particles strongly depends on the irradiation dose rate. Atomistic simulations can in principle be used to predict microstructural evolution where experimental data is sparse or unavailable, however, fundamental limitations of the method mak…
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UKAEA-CCFE-PR(25)3922024
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…
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UKAEA-CCFE-PR(25)3842024
Radiation creep and swelling are the macroscopic irreversible deformation phenomena, occurring in materials exposed to energetic particle irradiation even at low temperatures. On the microscopic scale, energetic particles initiate collision cascades, generating and…
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UKAEA-CCFE-PR(25)3892023
Swelling and microstructural evolution of nanocrystalline (NC) tungsten are investigated by atomic scale simulations exploring the low temperature, high radiation exposure limit. Statistical analysis of microstructures containing at least a million atoms, with the grain size varying from 5 nm to 20 nm, suggests that their evolution is dominated …
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UKAEA-CCFE-PR(24)062023
We describe the parameterization of a tungsten-hydrogen empirical potential designed for use with large-scale molecular dynamics simulations of highly irradiated tungsten containing hydrogen isotope atoms, and report test results. Particular attention has been paid to getting good elastic properties, including the relaxation volumes of small def…
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UKAEA-CCFE-PR(23)1712023
We simulate effects of irradiation on nanocrystalline tungsten in the athermal high dose limit using the creation-relaxation algorithm, where microstructural evolution is driven not by thermally activated diffusion, but by fluctuating stresses resulting from the production and relaxation of defects. Over the entire interval of radiation exposure sp…
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UKAEA-CCFE-PR(24)2382022
At temperatures below the onset of vacancy migration, metals exposed to energetic ions develop dynamically fluctuating steady-state microstructures. Statistical properties of these microstructures in the asymptotic high exposure limit are not universal and vary depending on the energy and mass of the incident ions. We develop a model for the micros…
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UKAEA-CCFE-PR(23)1312022
We derive a simple analytical line integral expression for the relaxation volume tensor of an arbitrary interconnected dislocation network. This quantity determines the magnitude of dislocation contribution to the dimensional changes and volumetric swelling of a material, and highlights the fundamental dual role of dislocations as sources of intern…
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UKAEA-CCFE-PR(22)072022
Self-ion irradiation of pure tungsten with 2 MeV W ions provides a way of simulating microstructures generated by neutron irradiation in tungsten components of a fusion reactor. Electron microscopy has been used to characterize defects formed in tungsten samples by ion irradiation and estimate their density and size distribution. Some of the sample…
Showing 1 - 10 of 32 UKAEA Paper Results