S.F. Smith S.J.P. Pamela A. Fil M. Hoelzl G.T.A. Huijsmans A. Kirk D. Moulton O. Myatra A.J. Thornton H.R. Wilson
ELM simulations for the MAST-U Super-X tokamak have been obtained, using the JOREK code. The JOREK visco-resistive MHD model has been used to obtain comparisons of divertor configurations. The simulations show a factor 10 decrease in the peak heat flux to the outer target of the Super-X in comparison to a conventional divertor configuration. A roll…
Preprint PublishedS.F. Smith S.J.P. Pamela M. Hölzl G.T.A. Huijsmans A. Kirk D. Moulton A.J. Thornton H.R. Wilson
During edge localised modes (ELMs) high heat fluxes are incident on divertor targets, which future fusion devices will not withstand [1]. A solution to reduce the heat fluxes could be the new Super-X divertor, which will be tested on the MAST-U tokamak. The divertor has an increased connection length, magnetic flux expansion and is designed to reta…
Preprint PublishedA. Dvornova G.T.A. Huijsmans S. Sharapov F.J. Artola P. Puglia M. Hoelzl S. Pamela A. Fasoli D. Testa
Toroidal Alfven Eigenmode (TAE) excitation can be caused by fusion-born or Ion Cyclotron Resonance and neutral beam heating fast particles through wave-particle resonance. TAEs may affect fast particle confinement, reduce heating and current drive efficiency, cause damage to the first wall, and decrease overall plasma performance. Excitation of TA…
Preprint PublishedChristopher Ham Andrew Kirk Stanislas Pamela Howard Wilson
Fusion is one of very few options for sustainable, baseload power to the grid that is necessary to meet the energy needs of future generations. The tokamak is the most advanced approach to fusion and, with the construction of ITER, we are approaching power plant conditions. While commercialisation of this key technology is a main driver for tokamak…
Preprint PublishedS.Pamela G.Huijsmans T.Eich S.Saarelma I.Lupelli C.Maggi C.Giroud I.Chapman S.F.Smith L.Frassinetti M.Becoulet M.Hoelzl F.Orain S.Futatani JET Contributors
Future devices like JT-60SA, ITER and DEMO require quantitative predictions of pedestal density and temperature levels, as well as inter-ELM and ELM divertor heat fluxes, in order to improve global confinement capabilities while preventing divertor erosion/melting in the planning of future experiments. Such predictions can be obtained from dedicate…
Preprint PublishedS. Pamela T. Eich L. Frassinetti B. Sieglin S. Saarelma G. Huijsmans M. Hoelzl M. Becoulet F. Orain S. Devaux I. Chapman I. Lupelli E. Solano JET Contributors
A subset of JET ITER-like wall (ILW) discharges, combining electron density and temperature as well as divertor heat flux measurements, has been collected for the validation of non-linear MHD simulations of Edge-Localised-Modes (ELMs). This permits a quantitative comparison of simulation results against experiments, which is required for the valida…
Preprint PublishedA. Kirk W. Suttrop I.T. Chapman Yueqiang Liu R. Scannell A.J. Thornton L. Barrera Orte P. Cahyna T. Eich R. Fischer C. Fuchs C. Ham J.R. Harrison MW. Jakubowski B. Kurzan S. Pamela M. Peterka D. Ryan S. Saarelma B. Sieglin M. Valovic M Willensdorfer MAST and ASDEX Upgrade Teams
Sustained Edge Localised Mode (ELM) mitigation has been achieved on MAST and AUG using RMPs with various toroidal mode numbers over a wide range of low to medium collisionality discharges. The ELM energy loss and peak heat loads at the divertor targets have been reduced. The ELM mitigation phase is typically associated with a drop in plasma density…
Preprint PublishedS. J. Freethy K. G. McClements S. C. Chapman R. O. Dendy W. N. Lai S. J. P. Pamela V. F. Shevchenko R. G. L. Vann
Recent measurements of microwave and x-ray emission during edge localized mode (ELM) activity in tokamak plasmas provide a fresh perspective on ELM physics. It is evident that electron kinetics, which are not incorporated in standard (fluid) models for the instability that drives ELMs, play a key role in the new observations. These effects should b…
Preprint PublishedA. Kirk D. Dunai M. Dunne G. Huijsmans S. Pamela M. Becoulet J.R. Harrison J. Hillesheim C. Roach S. Saarelma The Mast Team
The type I ELMy H-mode is the baseline operating scenario for ITER. While it is known that the type I ELM ultimately results from the peeling-ballooning instability, there is growing experimental evidence that a mode grows up before the ELM crash that may modify the edge plasma, which then leads to the ELM event due to the peeling-ballooning mode. …
PublishedI.T. Chapman A. Kirk R.J. Akers C.J. Ham J.R. Harrison J. Hawke Y.Q. Liu K.G. McClements S. Pamela S. Saarelma R. Scannell A.J. Thornton The Mast Team
ELM mitigation has been demonstrated in MAST using resonant magnetic perturbations (RMPs) with toroidal mode number, n RM P = 2, 3, 4, 6. It has been observed that the mitigated ELM frequency increases with the amplitude of the applied field provided it is above a critical threshold. This threshold value depends on the mode number of the RMP, with …
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