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UKAEA-CCFE-PR(19)442019
The low energy structures of irradiation-induced defects have been studied in detail, as these determine the available modes by which a defect can diffuse or relax. As a result, there are many studies concerning the relative energies of possible defect structures, and empirical potentials are commonly fitted to or evaluated with respect to these en…
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UKAEA-CCFE-PR(19)432019
Body-centered cubic metals and alloys irradiated by energetic particles form highly mobile prismatic dislocation loops with a/2 {111} -type Burgers vectors. We show how to simulate thermal diffusion of prismatic loops using a discrete dislocation dynamics approach that explicitly includes the stochastic forces associated with ambient thermal fluctu…
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UKAEA-CCFE-PR(19)402019
CALANIE (CALculation of ANIsotropic Elastic energy) program evaluates an elastic interaction correction to the total energy of a localized object, for example a defect in a solid material simulated using an {it ab initio} or molecular statics approach, resulting from the use of periodic boundary conditions. The correction, computed using a fully el…
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UKAEA-CCFE-PR(19)372019
The diffusion of defects in crystalline materials governs macroscopic behaviour in a wide range of processes, including alloying, precipitation, phase transformation, and creep. In real materials, intrinsic defects are unavoidably bound to static trapping centres such as impurity atoms, meaning that their diffusion is controlled by the de-trapping …
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UKAEA-CCFE-PR(19)172019
We describe the development of a new object kinetic Monte Carlo code where the elementary defect objects are off-lattice atomistic configurations. Atomic-level transitions are used to transform and translate objects, to split objects and to merge them together. This gradually constructs a database of atomic configurations- a set of relevant defect …
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UKAEA-CCFE-CP(18)072018
This paper addresses the EUROfusion DEMO materials research program and highlights the characterization of the in-vessel baseline materials EUROFER97, CuCrZr and tungsten as well as advanced structural and high heat flux materials developed for risk mitigation. In support of engineering design activities the focus primarily is to assemble a data ba…
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UKAEA-CCFE-PR(18)832018
Magnetic plasma confinement is a key element of fusion tokamak power plant design, yet changes in magnetic properties of alloys and steels occurring under neutron irradiation are often overlooked. We perform a quantitative study exploring how irradiation-induced precipitation affects magnetic properties of Fe-Cr alloys. Magnetic properties are simu…
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UKAEA-CCFE-PR(18)722018
Formation and migration energies, elastic dipole and relaxation volume tensors of nano-defects are the parameters that determine the rates of evolution of microstructure under irradiation and the magnitude of macroscopic elastic stresses and strains resulting from the accumulation of defects in materials. To find accurate values of these parameters…
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UKAEA-CCFE-PR(18)492018
Predicting strains, stresses and swelling in power plant components exposed to irradiation directly from the observed or computed defect and dislocation microstructure is a fundamental problem of fusion power plant design that has so far eluded a practical solution. We develop a model, free from parameters not accessible to direct evaluation or obs…
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UKAEA-CCFE-PR(18)382018
Conventional linear elasticity theory predicts the strain fields of a dislocation core to diverge, whereas it is known from atomistic simulations that strains at dislocation cores remain finite. We present an analytical solution to a generalised, variational Peierls-Nabarro model of edge dislocation displacement fields that features a finite core w…
Showing 41 - 50 of 121 UKAEA Paper Results