J.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 PublishedBogdan Hnat Nick Walkden The MAST Team
We study the amplitude modulation of the radial electric field constructed from the Langmuir probe plasma potential measurements at the edge of MAST. The Empirical Mode Decomposition technique is applied, which allows us to construct fluctuations on temporal scales of plasma turbulence, the Geodesic Acoustic Mode and these associated with the res…
Preprint PublishedF. Riva F. Militello S. Elmore J. T. Omotani B. Dudson N. R. Walkden MAST team
The STORM module of BOUT++ [L. Easy et al., Phys. Plasmas 21, 122515 (2014)] is generalized to simulate plasma turbulence at the periphery of tokamak devices in diverted configuration and it is used to carry out three-dimensional nonlinear flux-driven simulations in double null configuration with realistic experimental par…
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 PublishedB. Madsen M. Salewski J. Huang A. S. Jacobsen O. Jones K. G. McClements the MAST team
Velocity-space tomography provides a way of diagnosing fast ions in a fusion plasma by combining measurements from multiple instruments. We use a toroidally viewing and a vertically viewing fast-ion D-alpha (FIDA) diagnostic installed on the spherical tokamak MAST (before the upgrade) to perform velocity-space tomography of the fast-ion distributio…
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 PublishedDL Keeling CD Challis I Jenkins NC Hawkes I Lupelli C Michael MFM. de Bock the MAST Team JET contributors
Experiments have been carried out on the MAST and JET tokamaks intended to compare the electrical resistivity of the plasma with theoretical formulations. The tests consist of obtaining motional stark effect (MSE) measurements in MHD-free plasmas during plasma current ramp-up (JET and MAST), ramp-down (MAST) and in stationary state (JET and MAST). …
Preprint PublishedB. Hnat S. Gadgil A. Kirk F. Militello N. Walkden The MAST Team
Reciprocating Mach probe data is used to estimate the radial wave number of oscillatory zonal flows in Ohmic MAST plasma. An intermittent 10kHz mode is detected in the wavelet decomposition and windowed spectra of plasma potential fluctuations of the MAST tokamak edge plasma. Previously, this mode has been identified as a Geodesic Acoustic Mode (GA…
Preprint PublishedL. Yueqiang A. Kirk L. Li Y. In R. Nazikian Y. Sun W. Suttrop B. Lyons D. Ryan S. Wang X. Yang L. Zhou EUROfusion MST1 team
Extensive modelling efforts of the plasma response to the resonant magnetic perturbation fields, utilized for controlling the edge localized mode (ELM), help to identify the edge-peeling response as a key factor, which correlates to the observed ELM mitigation in several tokamak devices, including MAST, ASDEX Upgrade, EAST, and HL-2A. The recently …
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