Showing 1 - 10 of 99 Journals Results

2021

UKAEA-CCFE-PR(21)68

#### L. Reali M. Boleininger M. R. Gilbert S. L. Dudarev

#### 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…

Preprint2021

UKAEA-CCFE-PR(21)60

#### Andrew R. Warwick Max Boleininger Sergei L. Dudarev

#### Using atomistic simulations based on the creation-relaxation algorithm, we explore the evolution of microstructure in irradiated zirconium over a broad range of radiation exposure. In agreement with experimental observations, we find that at relatively low temperatures, microstructure evolves towards an asymptotic dynamic steady state forming at…

Preprint Published2021

UKAEA-CCFE-PR(21)56

#### Daniel R. Mason Fredric Granberg Max Boleininger Thomas Schwarz-Selinger Kai Nordlund Sergei L. Dudarev

#### Hydrogen isotopes are retained in materials for fusion power applications, changing both hydrogen embrittlement and tritium inventory as the microstructure undergoes irradiation damage. But modelling of the highly damaged regime – over 0.1 displacements per atom (dpa) – where asymptotic saturation is observed, is difficult because a highly dama…

Preprint2021

UKAEA-CCFE-PR(21)54

#### Pui-Wai Ma Sergei L. Dudarev

#### The concept of elastic dipole tensor of a defect is generalised to enable the treatment of lattice distortions, produced by defects at elevated temperatures. Thermodynamic and statistical mechanics derivations show the feasibility of computing the formation free energy and finite-temperature elastic dipole tensor of a $frac{1}{2}langle 111 rangle$ …

Preprint Published2021

UKAEA-CCFE-PR(21)33

#### K. Arakawa Z. Bergstrom M.J. Caturla S.L. Dudarev F. Gao M.R. Gilbert A.M. Goryaeva S.Y. Hu X. Hu R.J. Kurtz A. Litnovsky J. Marian M.-C. Marinica E. Martinez E.A. Marquis D.R. Mason B.N. Nguyen P. Olsson Y. Osetskiy D. Senor

#### Prediction of material performance in fusion reactor environments relies on computational modelling, and will continue to do so until the first generation of fusion power plants come on line and allow long-term behaviour to be observed. In the meantime, the modelling is supported by experiments that attempt to replicate some aspects of the eventua…

Preprint Published2021

UKAEA-CCFE-PR(21)01

#### M. Boleininger M. Gallauer S. L. Dudarev T. D. Swinburne D. R. Mason D. Perez

#### The ability of a body-centered cubic metal to deform plastically is limited by the thermally activated glide motion of screw dislocations, which are line defects with a mobility exhibiting complex dependence on temperature, stress, and dislocation segment length. We derive an analytical expression for the velocity of dislocation glide, based on a s…

Preprint2020

UKAEA-CCFE-PR(20)141

#### Pui-Wai Ma S L Dudarev

#### Using ab initio density function theory calculations, we have determined the structure of self-interstitial atom (SIA) defects in the most commonly occurring face-centred cubic (FCC) metals. The most stable SIA defects in Al, Ca, Ni, Cu, Pd and Ag are the {100} dumbbells whereas octahedral SIA configurations have the lowest energy in Pt, R…

Preprint Published2020

UKAEA-CCFE-PR(20)113

#### Suchandrima Das Daniel R. Mason Peter M. Derlet Sergei L. Dudarev Andrew London Hongbing Yu Nicholas Phillips David Yang Kenichiro Mizohata Ruqing Xu Felix Hofmann

#### Combining spatially resolved X-ray Laue diffraction with atomic-scale simulations, we observe how ion-irradiated tungsten undergoes a series of non-linear structural transformations with increasing irradiation exposure. Nanoscale defect-induced deformations accumulating above 0.02 displacements per atom (dpa) lead to highly fluctuating strains at ~…

Preprint Published2020

UKAEA-CCFE-PR(20)108

#### Pui-Wai Ma D. R. Mason S. L. Dudarev

#### We performed ab initio density functional theory simulations of 1/2{111} interstitial dislocation loops, closed and open vacancy loops, {100} interstitial loops and voids in tungsten, using simulation cells involving from 2000 to 2700 atoms. The size of the loops transcends the microscopic scale and reaches the mesoscopic scale where as…

Preprint Published2020

UKAEA-CCFE-PR(20)105