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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(23)1722023
Neutrons interacting with atomic nuclei in most of the materials included in the current fusion reactor designs—notably tungsten, ferritic and stainless steels, copper alloys—generate a γ-photon flux that is comparable in magnitude and e…
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UKAEA-CCFE-PR(23)1402023
We investigated the athermal irradiation-induced swelling and creep in iron subjecting to the application of external uniaxial stress. We studied this through atomic scale simulations using the creation-relaxation algorithm. We also calculated the defect relaxation volume density tensors (or eigenstrain) as a function of external uniaxial stress. B…
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UKAEA-CCFE-PR(24)2442022
Zirconium alloys are widely used as the fuel cladding material in pressurised water reactors where a significant population of defects and dislocations is produced by exposure to neutrons. We present and interpret synchrotron microbeam X-ray diffraction measurements of proton- irradiated Zircaloy-4, where we identify a transient peak and the sub…
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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(24)052022
Effects of neutron irradiation on materials are often interpreted in terms of atomic recoils, initiated by neutron impacts and producing crystal lattice defects. We find that, in addition, there is a remarkable two-step process, strongly pronounced in heavy elements, involving the generation of energetic γ-photons in non-elastic collisions of n…
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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(21)682021
Using the notion of eigenstrain produced by the defects formed in a material exposed to high energy neutron irradiation, we develop a method for computing macroscopic elastic stress and strain arising in components of a fusion power plant during operation. In a microstructurally isotropic material, the primary cause of macroscopic elastic stress an…
Showing 1 - 10 of 16 UKAEA Paper Results