S.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 PublishedStuart I. Muldrew Hanni Lux Tim C. Hender Bhavin Patel Peter J. Knight Garry M. Voss Howard R. Wilson
Spherical Tokamaks offer a number of potential advantages for a future fusion power plant. They have a high ratio of thermal to magnetic field pressure (beta) and strong flows, either of which could result in reduced turbulence. Fewer Toroidal Field (TF) coils and a different geometry offers the potential for new methods of remote maintenance …
Preprint PublishedG. J. McArdle L. Pangione M. Kochan
MAST has undergone a substantial upgrade [1], featuring among other things several new poloidal field coils mostly distributed around the new closed-throat divertor structure and an enlarged centre column. The considerable changes have required the plasma control software to be substantially re-written. The MAST digital plasma control system […
Preprint PublishedF. Militello R. Akers L. Appel B. Cannas S. Carcangiu B. Dudson A. Fanni T. Farley A. Kirk J.R. Harrison B. Lipshultz A. Montisci T. Nicholas J.T. Omotani F. Pisano F. Riva G. Sias N.R. Walkden A. Wynn the MAST JET5 teams
In magnetic confinement devices, boundary turbulence is responsible for transporting plasma and energy from the well-confined region towards the material surfaces where it can severely harm reactor relevant machines. It is therefore essential to develop a solid understanding of the mechanisms behind the transport in the edge of the plasma. Large fl…
Preprint PublishedF. Riva F. Militello J. T. Omotani B. Dudson S. D. Elmore S. Newton T. Nicholas N. R. Walkden the MAST team
In the present work, global, three-dimensional edge plasma turbulence simulations of a MAST L-mode attached plasma discharge are presented. Our study is based on the drift-reduced Braginskii equations, solved with the STORM module of BOUT++ for realistic MAST parameters in disconnected lower double null configuration. The plasma profiles are evolve…
Preprint PublishedN.R.Walkden B.D.Dudson C.Ham F.Militello D.Moulton F.Riva J.T.Omotani
A firm grasp of transport processes perpendicular to the magnetic field line is required in order to understand and predict heat and particle fluxes to divertor components in tokamaks. Perpendicular transport from the hot core into the scrape-off layer (SOL) upstream impacts the SOL profile at the divertor via parallel streaming along the magnetic …
Preprint PurchaseD A Ryan L Piron A Kirk Y Q Liu M Dunne L Li B Dudson W Suttrop the ASDEX Upgrade team the EUROfusion MST1 team
Edge Localised Modes (ELMs) in H-mode tokamak plasmas may be controlled or entirely suppressed by applying 3D magnetic perturbations (MPs). The applied perturbation is amplified by the plasma response, and it has previously been established that the size of the peeling component of this response is a reliable indicator for expected ELM control on A…
PreprintJ.F. Rivero-Rodriguez M. Garcia-Muñoz R. Martin J. Galdon-Quiroga J. Ayllon-Guerola R. J. Akers J. Buchanan D. Croft D. Garcia-Vallejo J. Gonzalez-Martin D. Harvey K.G. McClements M. Rodriguez-Ramos L. Sanchis-Sanchez the MAST Upgrade Team
The design and unique feature of the first MAST-U fast-ion loss detector (FILD) [M. Garcia-Muñoz, Rev. Sci. Instrum 80, 053503 (2009)] is presented here. The MAST-U FILD head is mounted on an axially and angularly actuated mechanism that makes…
Preprint PublishedYasmin Andrew Jan-Peter Baehner Ronan Battle Tomas Jirman and the MAST team
Analysis of the L-H and H-L transition power thresholds (Pth) and pedestal parameters are presented for the Mega Ampere Spherical Tokamak (MAST). The dependencies of Pth on the average, core plasma electron density, X-point height and plasma current are described. Increasing X-point distance from the divertor floor over 10-12 cm, is found to inc…
Preprint PublishedD.J. Battaglia S.P. Gerhardt A. Kirk L. Kogan J.E. Menard D. Mueller A.J. Thornton
Reduced models coupled to time-dependent axisymmetric vacuum field calculations are used to develop the prefill and feed-forward coil current targets required for reliable direct induction (DI) startup on the new MA-class spherical tokamaks, MAST-U and NSTX-U. The calculations are constrained by operational limits unique to each device, such as the…
Preprint Published