A. SABBAGH J.W. BERKERY Y.S. PARK J.H. AHN Y. JIANG J.D. RIQUEZES J. BUTT J. BIALEK J.G. BAK M.J. CHOI S.H. HAHN J. KIM J. KO W.H. KO J.W. LEE J.H. LEE K.D. LEE L. TERZOLO S.W. YOON R.E. BELL M.D. BOYER K. ERICKSON B. LEBLANC M. PODESTA Z.R.WANG J. YOO C. HAM A. KIRK L. KOGAN D. RYAN A. THORNTON J. HOLLOCOMBE F.M. LEVINTON M.GALLANTE
Disruption prediction and avoidance is critical for ITER and reactor-scale tokamaks to maintain steady plasma operation and to avoid damage to device components. The present status and results from the disruption event characterization and forecasting (DECAF) research effort are shown. The DECAF paradigm is primarily physics-based and provides q…
PreprintJ. W. Berkery S. A. Sabbagh J. Bialek Y. Jiang C. Ham L. Kogan D. Ryan A. Thornton G. Xia D. Battaglia Z. Wang A. Piccione Y. Andreopoulos L. Guazzotto S. Gibson Y. Q. Liu
In preparation for high fusion plasma performance operation of the newly operating spherical tokamak MAST-U, the equilibrium and stability properties of plasmas in the MAST database, as well as projections for MAST-U, are explored. The disruption event characterization and forecasting (DECAF) code is utilized to map disruptions in MAST, particul…
PreprintJ. R. Harrison T. Farley G. M. Fishpool A. Kirk B. Lipschultz J. Lovell F. Militello D. Moulton P. Ryan R. Scannell A. J. Thornton K. Verhaegh L. Xiang
The benefits of an optimised Super-X divertor configuration in mitigating the steady-state power and particle fluxes to the surfaces of the MAST Upgrade divertor have been quantified by performing a detailed comparison with a conventional divertor for the first time. In otherwise identical plasmas with conventional and Super-X divertor configu…
PreprintJ. W. Berkery S. A. Sabbagh L. Kogan D. Ryan J. M. Bialek Y. Jiang D. J. Battaglia S. Gibson C. Ham
Reconstructions of plasma equilibria using magnetic sensors and a Dα constraint were routine during operation of the MAST spherical tokamak, but reconstructions using kinetic profiles was not. These are necessary for stability and disruption analysis of the MAST database, as well as going forward for operation in the upgrade to the device, MAST…
Preprint PublishedW. Suttrop A. Kirk V. Bobkov M. Cavedon M. Dunne R.M. McDermott H. Meyer R. Nazikian C. Paz-Soldan D.A. Ryan E. Viezzer M. Willensdorfer The ASDEX Upgrade MST1 Teams
Access conditions for full suppression of edge localised modes (ELMs) by magnetic perturbations (MP) in low density high confinement mode (H-mode) plasmas are studied in the ASDEX Upgrade tokamak. The main empirical requirements for full ELM suppression in our experiments are: 1. The poloidal spectrum of the MP must be aligned for best plasma respo…
PublishedD. Hoare F. Militello J.T. Omotani F. Riva S. Newton T. Nicholas D. Ryan N.R. Walkden
The role of magnetic perturbations generated by filaments in the scrape-off layer is investigated by performing simulations of 3D seeded filaments with an electromagnetic numerical code which includes sheath boundary conditions. Depending on the plasma , three smoothly connecting regimes were identified: an electrostatic regime where the magnet…
Preprint PublishedRyan Sperry David T Fullwood Allan Harte Joao Quinta da Fonseca Eric R Homer Robert H Wagoner
Shear strain profiles along slip bands in a modified Rolls-Royce nickel superalloy (RR1000) were analyzed for tensile sample deformed by 2%. The strain increased with distance away from a grain boundary (GB), with maximum shear strain towards the center of the grain, indicating that dislocation nucleation generally occurred in the grain interior. T…
Preprint PublishedD 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…
PreprintD A Ryan M Dunne A Kirk S Saarelma W Suttrop C Ham Y Q Liu M Willensdorfer the ASDEX Upgrade team the MST1 team
A numerical survey of the plasma response in ASDEX Upgrade ELM control experiments is conducted, to clarify the role of triangularity in the suppression mechanism. The pedestal pressure increases with triangularity consistent with previous work [2], which modestly boosts the peeling response. However, the peeling response decreases with increasi…
Preprint PublishedJ.Galdon-Quiroga M.Garcia-Munoz S.Sharapov L.Sanchis-Sanchez L.Chen M.Dunne J.Gonzalez-Martin M.Hoelz A.S.Jacobsen K.G.McClements M.Nocente F.Orain J.F.Rivero-Rodriguez D.A.Ryan M.Salewski P.Schneider A.Snicker W.Suttrop Y.Todo M.A.Van Zeeland E.Viezzer M.Willensdorfer D.Zarzoso F.Zonca The ASDEX Upgrade Team MST1 Team
An edge resonant transport layer has been found to explain many aspects of fast-ion confinement under symmetry breaking 3D edge perturbations, such as edge localized modes (ELMs) and externally applied magnetic perturbations (MPs). Experimental measurements in the ASDEX Upgrade (AUG) tokamak show that fast-ion losses in the presence of symmetry bre…
Preprint Published