R. Darkins D. M. Duffy P.-W. Ma S. T. Murphy
Ultrafast irradiation can drive the electrons in a material out of thermal equilibrium with the nuclei, producing hot, transient electronic states that modify the interatomic potential energy surface. We present, for the first time, a rigorous formulation of two-temperature molecular dynamics that can accommodate these electronic effects in the fo…
Preprint PublishedD. Schwörer N. R. Walkden H. Leggate B. D. Dudson F. Militello T. Downes M. M. Turner
This paper presents the effect of self-consistent plasma backgrounds including plasma-neutral interactions, on the dynamics of filament propagation. The principle focus is on the influence of the neutrals on the filament through both direct interactions and through their influence on the plasma background. Both direct and indirect interactions infl…
Preprint PublishedL. Garzotti P. Belo G. Corrigan D. Harting F. Köchl A. Loarte E. Militello Asp V. Parail R.Ambrosino M. Cavinato M. Mattei M. Romanelli R. Sartori M. Valovič
The operation of a tokamak designed to test the sustainability of a thermonuclear grade plasma like the International Tokamak Experimental Reactor (ITER) presents several challenges. Among them is the necessity of fuelling the plasma to reach the density required to generate enough fusion power to achieve Q = 10 and, at the same time, to protect th…
Preprint PublishedM. Carr A. Meakins M. Bernert P. David C. Giroud J. Harrison S. Henderson B. Lipschultz F. Reimold the EUROfusion MST1 Team ASDEX Upgrade team
Ray-tracing techniques are applied to bolometry, a diagnostic particularly sensitive to machine geometry due to the effect of volume sampling. Sightlines from the ASDEX-Upgrade bolometer foils were ray-traced with a path tracing algorithm, where the optical path is represented by a statistical bundle of ray paths connecting the foil surface with th…
Preprint PublishedB. R. Colling T. Eade M. R. Gilbert J. Naish S. Zheng
Computational models created for neutronics assessment through solid geometry conversion are often specific to the analysis being performed. The use of unstructured mesh geometry has the potential to reduce the build time of MCNP models, reduce inaccuracies introduced through flux averaging over different components and material mixing, and make us…
Preprint PublishedD. Samaddar D.P. Coster X. Bonnin L.A. Berry W.R. Elwasif D.B.Batchelor
This paper explores the application of the parareal algorithm to simulations of ELMs in ITER plasma. The primary focus of this research is identifying the parameters that lead to optimum performance. Since the plasma dynamics vary extremely fast during an ELM cycle, a straightforward application of the algorithm is not possible and a modification t…
Preprint PurchaseL. W. Packer P. Batistoni S. Bradnam B. C. Colling S. Conroy Z. Ghania M. R. Gilbert S. Jednorog E. Laszyńska D. Leichtle I. Lengar J.W.Mietelski R. Misiak C.R.Nobs M. Pillon S. Popovichev V. Radulović I.E. Stamatelatos T. Vasilopoulou A. Wójcik-Gargula JET Contributors
This paper details progress in experimental characterisation work at JET for the long-term irradiation station conducted as part of a project to perform activation experiments using ITER materials. The aim is to take advantage of the significant 14 MeV neutron yield expected during JET operations to irradiate samples of materials that will be used …
Preprint PublishedK. G. McClements K. Tani R. J. Akers Y. Q. Liu K. Shinohara H. Tsutsui S. Tsuji-Iio
The application of non-axisymmetric resonant magnetic perturbations (RMPs) to low current plasmas in the Mega Amp Spherical Tokamak (MAST) was found to be correlated with substantial drops in neutron production, suggesting a significant degradation of fast ion confinement. The effects of such perturbations on fast ions in MAST have been modelled us…
Preprint PublishedB. Madsen M. Salewski J. Huang A. S. Jacobsen O. Jones K. G. McClements the MAST team
Velocity-space tomography provides a way of diagnosing fast ions in a fusion plasma by combining measurements from multiple instruments. We use a toroidally viewing and a vertically viewing fast-ion D-alpha (FIDA) diagnostic installed on the spherical tokamak MAST (before the upgrade) to perform velocity-space tomography of the fast-ion distributio…
Preprint PublishedE. Surrey
There are several programmes within the fusion community that are engaged in the design of fusion devices to follow the International Thermonuclear Experimental Reactor (ITER), referred to as “demonstrators”. These programmes have identified many issues over the past decade and research now concentrates on optimising the combination of systems …
Preprint Published