UKAEA Papers

"Dynamic model for an ensemble of interacting irradiation-induced defects in a macroscopic sample"

• Federico Baraglia
• Pui-Wai Ma

We develop a dynamic model for the evolution of an ensemble of hundreds of interacting irradiation-induced mobile nanoscale defects in a micrometre size sample. The model uses a Langevin defect dynamics approach coupled to a finite element model, treated using the superposition method. The elastic field of each defect is described by its elastic…

"Hybrid mean field and real space model for vacancy diffusion-mediated annealing of radiation defects"

• I. Rovelli
• S.L. Dudarev
• A.P. Sutton

The evolution of the defect microstructure in materials at high temperature is dominated by diffusion-mediated interactions between dislocations, vacancy clusters and surfaces. This gives rise to complex non-linear couplings between interstitial and vacancy-type dislocation loops, cavities and the field of diffusing vacancies that adiabatically …

"The yield of excited atoms in a beam formed by charge exchange in a partially ionized gas target"

• KH Berkner
• II King
• AC Riviere

"The ionization of excited hydrogen atoms by strong electric fields"

• AC Riviere
• DR Sweetman

"Electric field ionization probabilities for the hydrogen atom"

• DS Bailey
• JR Hiskes
• AC Riviere

"CALANIE: anisotropic elastic correction to the total energy, to mitigate the effect of periodic boundary conditions"

• Pui-Wai Ma
• S. L. Dudarev

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…

"Statistical model for diffusion-mediated recovery of dislocation and point defect microstructure"

• I. Rovelli
• S.L. Dudarev
• A.P. Sutton

The evolution of the defect microstructure in materials at high temperature is dominated by diffusion-mediated interactions between dislocations, vacancy clusters and surfaces. This gives rise to complex non-linear couplings between interstitial and vacancy-type dislocation loops, cavities and the field of diffusing vacancies that adiabatically fol…

"Analytic bond-order potential for the gallium arsenide system"

• D. A. Murdick
• X. W. Zhou
• H. N. G. Wadley
• D. Nguyen-Manh
• R. Drautz
• D. G. Pettifor

An analytic, bond-order potential BOP is proposed and parametrized for the gallium arsenide system. The potential addresses primary and secondary bonding and the valence-dependent character of heteroatomic bonding, and it can be combined with an electron counting potential to address the distribution of electrons on the GaAs surface. The potential …

"Spectral and evolutionary analysis of advection–diffusion equations and the shear flow paradigm"

• A. Thyagaraja
• N.L Oureiro
• P.J. Knight

Advection–diffusion equations occur in a wide variety of fields in many contexts of active and passive transport in fluids and plasmas. The effects of sheared advective flows in the presence of irreversible processes such as diffusion and viscosity are of considerable current interest in tokamak and astrophysical contexts, where they are thought …

"Experimental results from a diagnostic beamline for the PBXM experiment"

• J. R. Coupland
• I. L. S. Gray
• O. J. Hancock
• K. P. Martel
• J. W. Mepham
• et al.

The experimental performance of a high-brightness neutral-beam system is described which has been designed and manufactured by Culham Laboratory under contract to the Princeton Plasma Physics Laboratory. The neutral beam serves as a diagnostic on the PBX-M experiment and is used to perform studies of high-bet a, bean-shaped, neutral-beam-heated pla…