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UKAEA-CCFE-PR(26)4192025
Materials used in commercial D-T fusion reactors will be exposed to irradiation and a mixture of helium and hydrogen plasma. Modeling the microstructural evolution of such materials requires the use of large-scale molecular dynamics simulations. The focus of this study is to develop a fast EAM potential for the interactions among the three elements…
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UKAEA-CCFE-PR(26)4162025
We propose a computational scheme for the diffusion and retention of multiple hydrogen isotopes with multi-occupancy traps parameterized by first principles calculations. We show that it is often acceptable to reduce the complexity of the coupled differential equations for gas evolution by taking the dynamic steady state, a generalisation of the Or…
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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(26)4092024
We recast the Howie-Whelan equations for generating simulated transmission electron microscope (TEM) images, replacing the dependence on local atomic displacements with atomic positions only. This allows very rapid computation of simulated TEM images for arbitrarily complex atomistic configurations of lattice defects and dislocations in the dyna…
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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…
Showing 1 - 10 of 35 UKAEA Paper Results