M Cecconello
Spherical tokamaks are key for the successful design of operating scenarios of future fusion reactors in the areas of divertor physics, neutral beam current drive and fast ion physics. MAST Upgrade, which has successfully concluded its first experimental campaign, was specifically designed to address the role of the radial gradient of the fast ion…
PreprintA. Sperduti M. Cecconello S. Conroy A. Snicker
A discrepancy between predicted and measured neutron rates on MAST using TRANSP/NUBEAM was observed. Further causes of this discrepancy are here studied by means of TRANSP/NUBEAM and ASCOT/BBNBI simulations. Gyro-Orbit simulations resulted in an approximately 20 % reduction of the fast ion density compare to the Guiding Center with TRANSP/NUBEAM…
Preprint PublishedA. R. Jackson A. S. Jacobsen K. G. McClements C. A. Michael M. Cecconello
The efficient confinement of fast ions is crucial to the development of a fusion power plant. Sawtooth crashes are a manifestation of an internal kink instability, which can severely degrade this confinement. The effect of these on a fast ion population can be investigated using fast-ion deuterium-alpha (FIDA) spectroscopy, where charge exchange…
Preprint PublishedJames Harrison RJ Akers SY Allan JS Allcock JO Allen L Appel M Barnes N Ben Ayed W Boeglin C Bowman J Bradley P Browning P Bryant M Carr M Cecconello CD Challis S Chapman IT Chapman GJ Colyer S Conroy NJ Conway M Cox G Cunningham RO Dendy W Dorland BD Dudson L Easy SD Elmore T Farley X Feng AR Field A Fil GM Fishpool M Fitzgerald
Recent results from MAST address key physics issues for ITER operations and the design of future devices, by advancing our understanding of through analysis of high-resolution data and numerical modelling. Modelling of the interaction between filaments with BOUT++ indicates filaments separated by more than 5x their width move independently, and …
Preprint PublishedMarco Cecconello A. Sperduti I. Fitzgerald S. Conroy S. J. Holm M. Weiszflog
A Neutron Camera (NC) was used on the Mega Ampere Spherical Tokamak (MAST) to measure the DD neutron emissivity along four collimated lines of sight, two on-axis and two off-axis, all viewing the plasma in tangential direction. The encouraging results obtained suggested that an upgraded NC for MAST-U would provide fundamental information for the st…
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 PublishedD. L. Keeling T. R. Barrett M. Cecconello C. D. Challis N. Hawkes O. M. Jones I. Klimek K. G. McClements A. Meakins J. Milnes M. Turnyanskiy The MAST team
The phenomenon of redistribution of neutral beam fast-ions due to MHD activity in plasma has been observed on many tokamaks and more recently has been a focus of research on MAST ( Turnyanskiy M. et al, 2013 Nucl. Fusion 53 053016 ). n=1 fishbone modes are observed to cause a large decrease in the neutron emission rate indicating to exist a signifi…
Preprint PublishedO.M. Jones M. Cecconello K.G. McClements I. Klimek R.J. Akers W.U. Boeglin D.L. Keeling A.J. Meakins R.V. Perez S.E. Sharapov M. Turnyanskiy The MAST team
The results of a comprehensive investigation into the effects of toroidicity- induced Alfven eigenmodes (TAE) and energetic particle modes on the NBI-generated fast-ion population in MAST plasmas are reported. Fast-ion redistribution due to frequency-chirping TAE in the range 50 kHz to 100 kHz, and frequency-chirping energetic particle modes known …
Preprint PublishedK. G. McClements R. J. Akers W.U. Boeglin M. Cecconello D. Keeling O.M. Jones A. Kirk I. Klimek R.V. Perez K. Shinohara K. Tani
The effects of resonant magnetic perturbations (RMPs) on the confinement of energetic (neutral beam) ions in the Mega Amp Spherical Tokamak (MAST) are assessed experimentally using measurements of neutrons, fusion protons and fast ion D _ (FIDA) light emission. In single null-diverted (SND) MAST pulses with relatively low plasma current (400 kA), t…
Preprint PublishedM. Weiszflog S. Sangaroon M. Cecconello S. Conroy G. Ericsson I. Klimek D. Keeling R. Martin M. Turnyanskiy
This paper presents two different conceptual designs of neutron cameras for Mega Ampere Spherical Tokamak (MAST) Upgrade. The first one consists of two horizontal cameras, one equatorial and one vertically down-shifted by 65 cm. The second design, viewing the plasma in a poloidal section, also consists of two cameras, one radial and the other one w…
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