A. Hollingsworth M.-F. Barthe M.Yu. Lavrentiev P.M. Derlet S.L. Dudarev D.R. Mason Z. Hub P. Desgardin J. Hess S. Davies B. Thomas H. Salter E.F.J. Shelton K. Heinolade K. Mizohatad A. De Backera A. Baron-Wiechec I. Jepuh Y. Zayachuka A. Widdowson E. Meslini A. Morelleci
Self-ion irradiation of pure tungsten with 2 MeV W ions provides a way of simulating microstructures generated by neutron irradiation in tungsten components of a fusion reactor. Electron microscopy has been used to characterize defects formed in tungsten samples by ion irradiation and estimate their density and size distribution. Some of the sample…
Preprint PurchaseDaniel R. Mason Abdallah Reza Fredric Granberg Felix Hofmann
The changing thermal conductivity of an irradiated material is among the principal design considerations for any nuclear reactor, but at present few models are capable of predicting these changes starting from an arbitrary atomistic model. Here we present a simple model for computing the thermal diffusivity of tungsten, based on the conductivity…
Preprint PurchaseDaniel 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…
Preprint PurchaseK. 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 PublishedM. 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…
Preprint PublishedSuchandrima 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 PublishedPui-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 PublishedA. Hollingsworth M.-F. Barthe Z. Hu P. Desgardin M.Yu. Lavrentiev S.L. Dudarev P. Derlet D. Mason J. Hess S. Davies B. Thomas H. Salter E.F.J. Shelton K. Heinola K. Mizohata A. De Backer A. Baron-Wiechec I. Jepu E. Zayachuk A. Widdowson E. Meslin A. Morellec
Self-ion bombardment of pure tungsten with ion energies of 2 MeV is used to mimic the defects created by neutrons in a fusion reactor. Electron microscopy is used to characterize the microstructure of samples. Thermal Desorption Spectrometry (TDS) is performed on deuterium implanted samples in order to estimate deuterium inventory as function of…
PreprintJan Fikar Robin Schaeublin Daniel R. Mason Duc Nguyen-Manh
The vacancies produced in high energy collision cascades of irradiated tungsten can form vacancy clusters or prismatic vacancy dislocation loops. Moreover, vacancy loops can easily transform into planar vacancy clusters. We investigated the formation energies of these three types of vacancy defects as a function of the number of vacancies using thr…
Published