M. R. Hardman M. Barnes C. M. Roach
Magnetised plasma turbulence can have a multiscale character: instabilities driven by mean temperature gradients drive turbulence at the disparate scales of the ion and the electron gyroradii. Simulations of multiscale turbulence, using equations valid in the limit of infinite scale separation, reveal novel cross-scale interaction mechanisms in …
Preprint PublishedH. Lux M. Morgan M. Siccinio W. Biel G. Federici R. Kembleton A. W. Morris E. Patelli H. Zohm
During the pre-conceptual design phase of fusion devices such as the European demonstration fusion power plant (DEMO), systems codes provide a fast evaluation of optimal design points and highlight high impact areas. However, determining or evaluating a design point at such an early stage comes with uncertainties in many of the design parameters. T…
Preprint PublishedD. Hoare F. Militello J.T. Omotani F. Riva S. Newton T. Nicholas D. Ryan N.R. Walkden
The role of magnetic perturbations generated by filaments in the scrape-off layer is investigated by performing simulations of 3D seeded filaments with an electromagnetic numerical code which includes sheath boundary conditions. Depending on the plasma , three smoothly connecting regimes were identified: an electrostatic regime where the magnet…
Preprint PublishedA. Fernandez-Caballero E. Bousser S.M. Shubeita P.T. Wady Y.Gue Ram Krishna M. Gorley D. Nguyen-Manh P. M. Mummery E.J. Pickering
One of the key challenges for the development of high-performance fusion materials is to design materials capable of maintaining mechanical and structural integrity under the extreme levels of displacement damage, high temperature and transmutation rates. High-entropy alloys (HEAs) and other concentrated alloys have attracted attention with rega…
Preprint PublishedDamian Sobieraj Jan S. Wróbel Tomasz Rygier Krzysztof J. Kurzydłowski Osman El Atwani Arun Devaraj Enrique Martinez Saez Duc Nguyen-Manh
The development of High-Entropy Alloys (HEAs) focuses on exploring compositional regions in multicomponent systems with all alloy elements in equal or near-equal atomic concentrations. Initially it was based on the main idea that high mixing configurational entropy contributions to the alloy free energy could promote the formation of a single so…
Preprint PublishedAlexander J. Leide Edmund Tarleton Richard I. Todd David E. J. Armstrong
Ion implantation is widely used as a surrogate for neutron irradiation in the investigation of radiation damage on the properties of materials. Due to the small depth of damage, micromechanical methods must be used to extract material properties. In this work, nanoindentation has been applied to ion irradiated silicon carbide to extract radiatio…
PreprintAlexander J. Leide Matthew J. Lloyd Richard I. Todd David E. J. Armstrong
Raman spectroscopy has been used to identify defective bonding in neon and silicon ion irradiated single crystals of 6H-SiC. Observable differences exist in the CC bonding region corresponding to different defect structures for neon and silicon ion implantations. Evidence of oxidation during high temperature ion implantation is observed as C-O a…
PreprintP.D. Edmondson B. Gault M.R. Gilbert
Tungsten is the prime candidate material for the plasma facing divertor system and first wall armor of future nuclear fusion reactors. However, the understanding of the microstructural and chemical evolution of pure tungsten under neutron irradiation is relatively unknown, in part due to a lack of experimental data on this topic. Here, single cr…
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 PublishedCameron McElfresh Yinan Cui Sergei Dudarev Giacomo Po Jaime Marian
Dislocation climb is an important high temperature process of metals plasticity, responsible for phenomena such as creep, swelling, or hardening. Climb is defined by the ability of dislocations to leave their original glide plane by interaction with point defects. As such, dislocation climb is controlled by point defect diffusion/absorption/emis…
Preprint Published