Y. Zayachuk D.E.J. Armstrong K. Bystrov S. Van Boxel T. Morgan S. G. Roberts
Tungsten samples were heat-treated to achieve partial recrystallization and exposed to high ion flux deuterium plasma at different temperatures and fluences. Continuous stiffness nanoindentation measurements of near-surface hardness were performed in the grains of specific annealing states and of specific crystallographic orientation, determined by…
Preprint PublishedM. Kovari
Calculations of the heat flux carried by plasma to the wall of a magnetic fusion machine often assume that power flows only along the field lines, but this cannot be true in general. Instead, we treat the plasma as an anisotropic non-linear thermally conducting medium. The model is physically relevant if parallel and cross-field transport are drive…
PreprintJ.Leddy B. Dudson M. Romanelli B. Shanahan N. Walkden
Tokamak plasmas are confined by a magnetic field that limits the particle and heat transport perpendicular to the field. Parallel to the field the ionised particles can move freely, so to obtain confinement the field lines are “closed" (ie. form closed surfaces of constant poloidal flux) in the core of a tokamak. Towards, the edge, however, the …
Preprint PublishedLlion Evans T. Minniti M. Fursdon M. Gorley T. Barrett F. Domptail E. Surrey W. Kockelmann A.v. Müller F. Escourbiac A. Durocher
Within a tokamak fusion energy device, the performance and lifespan of a divertor monoblock under high heat flux cycles is of particular interest. Key to this is the quality of manufacture, especially the material joining interfaces. Presented here is a comparative study between X-ray and neutron tomography to investigate the quality of manufacture…
Preprint PublishedMichael Komm Stuart Henderson Sarah Elmore COMPASS team EUROfusion MST1 team
Partial detachment is the desired regime for the baseline burning plasma scenario in ITER and next-step devices, as it allows to disspate the majority of the energy carried by charged particles through the scrape-off-layer (SOL) and thus avoids localised heat flux deposition in the divertor region. The COMPASS tokamak is equipped with an open diver…
Preprint PublishedVasili Kiptily F. Belli J. Eriksson C. Hellesen V.Goloborod’ko K.Schöpf
An effect due to fusion born triton production has been observed in JET high-performance deuterium plasma discharges with NBI and H-minority ICRF heating, using DD and DT neutron spectrometry as well as fusion product loss measurements. The observations show that increase of the triton burn up rate leads to decrease of second harmonic ωcH
Preprint PublishedL. Garzotti E. Barbato J. Garcia N. Hayashi G.Giruzzi P. Maget M. Romanelli S. Saarelma R. Stankiewitz M. Yoshida I. Voitsekhovitch R. Zagórski
Reference scenarios for the JT-60SA tokamak have been simulated with one-dimensional transport codes to assess the stationary state of the flat-top phase and provide a profile database for further physics studies (e.g. MHD stability, gyrokinetic analysis) and diagnostics design. The types of scenario considered vary from pulsed standard H-mode to a…
Preprint PublishedV. G. Kiptily M. Fitzgerald V. Goloborodko S. E. Sharapov C. D. Challis D. Frigione J. Graves M. J. Mantsinen P. Beaumont M. Garcia-Munoz C. Perez von Thun J. F. R. Rodriguez D. Darrow D. Keeling D. King K. G. McClements E. Solano S. Schmuck G. Sips G. Szepesi JET contributors
During development of a high-performance hybrid scenario for future deuterium–tritium experiments on the Joint European Torus, an increased level of fast ion losses in the MeV energy range was observed during the instability of high-frequency n = 1 fishbones. The fishbones are excited during deuterium neutral beam injection combined with…
Preprint PublishedD.R. Mason D. Nguyen-Manh C.S. Becquart
We present an empirical interatomic potential for tungsten, particularly well suited for simulations of vacancy-type defects. We compare energies and structures of vacancy clusters generated with the empirical potential with an extensive new database of values computed using density functional theory, and show that the new potential predicts low-en…
Preprint PurchaseC. J. Ham I. T. Chapman J. Simpson Y. Suzuki
Tokamaks are traditionally viewed as axisymmetric devices. However this is not always true, for example in the presence of saturated instabilities, error fields, or resonant magnetic perturbations (RMPs) applied for edge localized mode (ELM) control. We use the VMEC code (Hirshman and Whitson 1983 Phys. Fluids 26 3553) to …
Preprint Published