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UKAEA-CCFE-PR(25)3082025
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UKAEA-CCFE-PR(25)3482024
Determining stress and strain in a component of a fusion power plant involves defining boundary conditions for the mechanical equilibrium equations, implying the availability of a full reactor model for defining those conditions. To address this fundamental challenge of reactor design, a finite element method (FEM) model for the Mega-Ampere Spheric…
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UKAEA-CCFE-PR(24)2262023
Fusion reactor components will be exposed to fluxes of high energy neutrons while also being subjected to thermal, mechanical and magnetic loads. Exposure to neutron irradiation has numerous consequences, including swelling a…
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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)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)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(23)1162022
Using exchange Monte Carlo (MC) simulations based on an ab initio-parameterized Cluster Expansion (CE) model, we explore the phase stability of low-Cr Fe-Cr alloys as a function of vacancy (Vac), carbon, and nitrogen interstitial impurity content. To parameterise the CE model, we perform density functional theory calculations for more than 1600 …
Showing 1 - 10 of 117 UKAEA Paper Results