M. R. Gilbert P. Schuck B. Sadigh J. Marian
In body-centered-cubic (bcc) crystals, 1/2{111} screw dislocations exhibit high intrinsic lattice friction as a consequence of their nonplanar core structure, which results in a periodic energy landscape known as the Peierls potential UP. The main features determining plastic flow, including its stress and temperature dependences, can be derived di…
PublishedT. D. Swinburne S. L. Dudarev S. P. Fitzgerald M. R. Gilbert A. P. Sutton
Isolated kinks on thermally fluctuating 1/2 111 screw, 100 edge, and 1/2 111 edge dislocations in bcc iron are simulated under zero stress conditions using molecular dynamics (MD). Kinks are seen to perform stochastic motion in a potential landscape that depends on the dislocation character and geometry, and their motion provides fresh insight …
PublishedM.R. Gilbert S.L. Dudarev D.Nguyen-Manh L.W. Packer J-Ch. Sublet
In a fusion reactor materials will be subjected to significant fluxes of high-energy neutrons. As well as causing radiation damage, the neutrons also initiate nuclear reactions leading to changes in the chemical composition of materials (transmutation). Many of these reactions produce gases, particularly helium, which cause additional swelling and …
PublishedM-C Marinica Lisa Ventelon M R Gilbert L Proville S L Dudarev J Marian G Bencteux F Willaime
We have developed empirical interatomic potentials for studying radiation defects and dislocations in tungsten. The potentials use the embedded atom method formalism and are fitted to a mixed database, containing various experimentally measured properties of tungsten and ab initio formation energies of defects, as well as ab initio interatomic forc…
PublishedL. W. Packer S. Hughes M. Gilbert S. Lilley R. Pampin
This work presents new integral data measured at the ASP 14 MeV neutron irradiation facility at Aldermaston in the UK, which has recently become available for fusion-related work through the CCFE materials programme. Measurements of reaction products from activation experiments using elemental foils were carried out using gamma spectrometry in a hi…
PublishedJean-Christophe Sublet Mark R. Gilbert
The calculation of activation inventories is a key input to virtually all aspects of the operation, safety and environmental assessment of nuclear plants. For the licensing of such devices, regulatory authorities will require proof that the calculations of structural material, fuel inventories, and calculations to which those quantities are the inp…
M.R. Gilbert S.L. Dudarev S. Zheng L.W. Packer J.-Ch. Sublet
The high-energy, high-intensity neutron fluxes produced by the fusion plasma will have a significant life-limiting impact on reactor components in both experimental and commercial fusion devices. As well as producing defects, the neutrons bombarding the materials initiate nuclear reactions, leading to transmutation of the elemental atoms. Products …
PublishedM. R. Gilbert S. Queyreau J. Marian
The low-temperature plastic yield of a -Fe single crystals is known to display a strong temperature dependence and to be controlled by the thermally activated motion of screw dislocations. In this paper, we present molecular dynamics simulations of 1 2 111{112} screw dislocation motion as a function of temperature and stress in order to extract mob…
PublishedP. M. Derlet M. R. Gilbert S. L. Dudarev
Nanoscale prismatic loops are modeled via a partial stochastic differential equation that describes an overdamped continuum elastic string, with a view to describing both the internal and collective dynamics of the loop as a function of temperature. Within the framework of the Langevin equation, expressions are derived that relate the empirical par…
Published