S. L. Dudarev D. R. Mason E. Tarleton P.-W. Ma A. E. Sand
Predicting strains, stresses and swelling in power plant components exposed to irradiation directly from the observed or computed defect and dislocation microstructure is a fundamental problem of fusion power plant design that has so far eluded a practical solution. We develop a model, free from parameters not accessible to direct evaluation or obs…
Preprint PublishedH. Wilson
Some of the main plasma physics challenges associated with achieving the conditions for commercial fusion power in tokamaks are reviewed. The confinement quality is considered to be a key factor, having an impact on the size of the reactor and exhaust power that has to be managed. Plasma eruptions can cause excessive erosion if not mitigated, with …
Preprint PublishedM. Cecconello W. Boeglin D. Keeling S. Conroy I. Klimek R. V. Perez the MAST team
Experimental evidence is presented of a discrepancy between the predicted and measured D-D fusion products rates on MAST. Both the neutron and proton production rates, measured independently with a neutron camera and charged fusion product detector array, are approximately 40 % lower than those predicted by TRANSP/NUBEAM codes. This deficit is scen…
Preprint PublishedN. R. Walkden B. Labit H. Reimerdes J. Harrison T. Farley P. Innocente F. Militello the TCV Team the MST1 Team
Tangentially viewing fast camera footage of the low-field side snowflake minus divertor in TCV is analysed across a four point scan in which the proximity of the two X-points is varied systematically. The apparent flow observed in the post-processed movie shows two distinct regions of the camera frame exhibiting differing flow patterns. One flow in…
Preprint PublishedS. S. Henderson M. M. Bluteau M. G. O’Mullane H. P. Summers
Spectra line power by medium and heavy weight elements is a main source of radiative loss in tokamak plasma and sets operational limits on the design of ITER and DEMO. The preferred comprehensive basis of impurity line power coefficients provided by ADAS is theoretical, using the Autostructure code with distorted wave electron impact cross-sections…
PreprintM. 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 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 PublishedY. Q. Wang H. E. Coules C. E. Truman D. J. Smith
Elastic follow-up is a mechanical boundary condition lying between constant load and constant strain control. It exists in many engineering components operating at high temperature and can result in dramatically different creep stress relaxation and strain accumulation rates in a localized region of a component. We have performed creep tests under …
Preprint PublishedM. Kovari M. Coleman I. Cristescu R. Smith
The tritium required for ITER will be supplied from the CANDU production in Ontario, but while Ontario may be able to supply 8 kg for a DEMO fusion reactor in the mid-2050s, it will not be able to provide 10 kg at any realistic starting time. The tritium required to start DEMO is uncertain within a wide margin; stocks would likely have to be shared…
Preprint PublishedN. R. Walkden J. Harrison S. A. Silburn T. Farley S.S. Henderson A. Kirk F. Militello A.Thornton the MAST Team
Using high speed imaging of the divertor volume, the region close to the X-point in MAST is shown to be quiescent. This is confirmed by three different analysis techniques and the quiescent X-point region (QXR) spans from the separatrix to the N = 1.02 flux surface. Local reductions to the atomic density and effects associated with the camera vie…
Preprint Published