Overview of recent physics results from MAST

Kirk, A.; Adámek, Jiřı́; Akers, R.; Allan, S.; Appel, L. C.; Lucini, F Arese; Barnes, Michael; Barrett, T.; Ayed, N. Ben; Boeglin, W.; Bradley, James W.; Browning, Philippa; Brunner, Jakob; Cahyna, P.; Carr, M.; Casson, F. J.; Cecconello, M.; Challis, C.; Chapman, I. T.; Chapman, S. C.; Conroy, S.; Conway, N. J.; Cooper, W.; Cox, M.; Crocker, N. A.; Crowley, B.; Cardnell, Sandy; Chorley, J.; Cunningham, G.; Данилов, А. В.; Darrow, D. S.; Dendy, R. O.; Dickinson, David; Dorland, W.; Dudson, B.; Easy, Luke; Elmore, S.; Evans, M. E. G.; Farley, Tom; Fedorczak, N.; Field, A.R.; Fitzgerald, I.; Fox, Michael F. J.; Freethy, S. J.; Garzotti, L.; Ghim, Y-c; Gi, Keii; Gorelenkova, M.; Gracias, William Agnelo; Gurl, C.; Guttenfelder, W.; Ham, Christopher; Harting, D.; Havlickova, E.; Hawkes, N.; Hender, T. C.; Henderson, S.; Hillesheim, J. C.; Hnat, B.; Horáček, J.; Howard, J.; Howell, D. F.; Dunai, D.; Fishpool, G.; Gibson, K.J.; Harrison, J.; Highcock, Edmund; Huang, Billy; Inomoto, Michiaki; Imazawa, Ryota; Jones, O.; Kadowaki, Kazutake; Kaye, S. M.; Keeling, D.; Kočan, M.; Kogan, L. A.; Komm, M.; Lai, W. N.; Leddy, Jarrod; Leggate, H.; Imada, Koki; Klimek, Iwona; Hollocombe, J.; Lipschultz, B.; Lisgo, S.; Yq, Liu; Lloyd, B.; Lomanowski, B.; Lukin, V. S.; Maddison, G.; Madsen, J.; Mailloux, J.; Martin, Richard L.; McArdle, G.; Lupelli, I.; McClements, K. G.; McMillan, B. F.; Meakins, A.; Meyer, H.; Michael, C; Militello, F.; Milnes, J.; Motojima, G.; Muir, D.G.; Naylor, G.; Nielsen, A. H.; O’Brien, M.R.; O’Mullane, M.; Olsen, J.; Omotani, John; Ono, Yoshio; Pamela, S.; Morris, A.W.; O’Gorman, T.; Pangione, L.; Parra, Félix I.; Patel, A.; Peebles, W. A.; Perez, R. V.; Pinches, S. D.; Piron, L.; Price, M.; Reinke, M.L.; Ricci, Paolo; Riva, Fabio; Roach, C. M.; Romanelli, M.; Ryan, D. A.; Saarelma, S.; Saveliev, A. N.; Scannell, R.; Schekochihin, A. A.; Sharapov, S. E.; Sharples, R. M.; Shevchenko, V.; Shinohara, K.; Silburn, S.; Simpson, J.; Stanier, Adam; Storrs, J.; Summers, H. P.; Takase, Y.; Tamain, P.; Tanabe, Hiroshi; Tanaka, H.; Tani, K.; Taylor, D.; Thomas, D. A.; Thomas-Davies, N.; Thornton, A.; Turnyanskiy, M.; Valovič, M.; Vann, R. G. L.; Wyk, Ferdinand Van; Walkden, N.; Watanabe, T.; Wilson, H. R.; Wischmeier, M.; Yamada, Teppei; Young, J.; Zoletnik, S.; Team, Mast; Team, EUROfusion Mst

doi:10.1088/1741-4326/aa65e0

Cited by 17 publications

(20 citation statements)

References 88 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…MAST 15 is a low aspect ratio R/a ≈ 1.3 tokamak with major radius R ≈ 0.85 m and minor radius a ≈ 0.65 m. We study the fast-ion distributions before (t = 0.253 s) and after (t = 0.279 s) a sawtooth crash observed by the dual-view FIDA diagnostics with lines-of-sight intersecting the NBI beam (E inj ≈ 56 keV) at r = 1.13 m during shot #29881. For this shot, the spatial and temporal resolutions of the FIDA diagnostics were about 10 cm and 2 ms, respectively.…”

Section: Modelled and Experimental Signalsmentioning

confidence: 99%

Velocity-space tomography using prior information at MAST

Madsen

Salewski

Huang

et al. 2018

Review of Scientific Instruments

Self Cite

View full text Add to dashboard Cite

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 fastion D-alpha diagnostic installed on the mega-amp spherical tokamak (before the upgrade) to perform velocity-space tomography of the fast-ion distribution function. To make up for the scarce amount of data, prior information is included in the inversions. We impose a non-negativity constraint, suppress the distribution in the velocity-space region associated with null-measurements, and encode the belief that the distribution function does not extend to energies significantly higher than those expected neoclassically. This allows us to study the fast-ion velocity distributions and the derived fast-ion densities before and after a sawtooth crash.

show abstract

Section: Modelled and Experimental Signalsmentioning

confidence: 99%

Velocity-space tomography using prior information at MAST

Madsen

Salewski

Huang

et al. 2018

Review of Scientific Instruments

Self Cite

View full text Add to dashboard Cite

show abstract

“…In parallel, dedicated RMP spectral optimization studies have converged on the crucial role of maximizing resonant coupling to the edge rational surfaces [21,7,22], and if conditions require it, maximizing edge resonant coupling while holding core resonant coupling to a sufficiently low value to avoid penetration of the core resonant surfaces [10,23,24]. Though the reason ∆ up was so effective in AUG is not yet resolved, an increase in edge resonant coupling may partially explain this result.…”

Section: Introductionmentioning

confidence: 99%

The effect of plasma shape and neutral beam mix on the rotation threshold for RMP-ELM suppression

et al. 2019

Self Cite

View full text Add to dashboard Cite

Varying the neutral beam injection (NBI) mix reveals a clear pedestal-top rotation threshold for edge localized mode (ELM) suppression by resonant magnetic perturbations. Guided by expectations for the RMP penetration mechanism, the rotation threshold is found to correspond to a critical radius for the ExB rotation zero-crossing. No such critical radius is observed for the electron perpendicular rotation zero-crossing. Varying the amount and ratio of power in different NBI source geometries (termed the NBI mix) also reveals that the rotation threshold can be crossed at widely varying total injected NBI torques. Computing the local torque density at the edge, the rotation threshold is found to be crossed when the local edge NBI torque is negative in nearly all discharges. Reducing the upper triangularity from the ITERsimilar value of 0.3 to 0.1 significantly reduces the pedestal height and width. This in turn: 1) Increases the rotation threshold and yields a more outward critical ExB rotation zero-crossing location. 2) Decreases the density threshold, consistent with a comparable collisionality range at lower pedestal temperatures. 3) Increases the input torque requirement, due to observed lower confinement and smaller intrinsic torque. These findings represent an important step along the road to predicting ELM suppression access conditions in future tokamaks such as ITER, where the toroidal rotation is expected to be low and consequently the rotation zero-crossing far from the pedestal-top.

show abstract

“…The main UKAEA facilities existing and in development are: JET [1], the world's largest and most capable fusion facility today, capable of using tritium, is operated by the UK for exploitation as a key part of the EUROfusion roadmap to fusion electricity (). JET is a model for ITER [2] and is the best facility to mitigate risks ahead of ITER operation.MAST Upgrade [4,8], together with NSTX-U [9], are the world's largest ‘spherical’ tokamaks. MAST Upgrade has unique features focused on the exhaust issue, challenge (ii), and will be developed and exploited with EUROfusion.…”

Section: Overview Of Ukaea's Contributions To the Fusion Researchand mentioning

confidence: 99%

“…JET is a model for ITER [2] and is the best facility to mitigate risks ahead of ITER operation. -MAST Upgrade [4,8], together with NSTX-U [9], are the world's largest 'spherical' tokamaks. MAST Upgrade has unique features focused on the exhaust issue, challenge (ii), and will be developed and exploited with EUROfusion.…”

Section: Overview Of Ukaea's Contributions To the Fusion Research And Development Challengesmentioning

confidence: 99%

UKAEA capabilities to address the challenges on the path to delivering fusion power

Chapman

Morris

2019

Phil. Trans. R. Soc. A.

View full text Add to dashboard Cite

Fusion power could be one of very few sustainable options to replace fossil fuels as the world's primary energy source. Fusion offers the potential of predictable, safe power with no carbon emissions and fuel sources lasting for millions of years. However, it is notoriously difficult to achieve in a controlled, steady-state fashion. The most promising path is via magnetic confinement in a device called a tokamak. A magnetic confinement fusion (MCF) power plant requires many different science, technology and engineering challenges to be met simultaneously. This requires an integrated approach from the outset; advances are needed in individual areas but these only bring fusion electricity closer if the other challenges are resolved in harmony. The UK Atomic Energy Authority (UKAEA) has developed a wide range of skills to address many of the challenges and hosts the JET device, presently the only MCF facility capable of operating with both the fusion fuels, deuterium and tritium. Recently, several major new UKAEA facilities have been funded and some have started operation, notably a new spherical tokamak (MAST Upgrade), a major robotics facility (RACE), and a materials research facility (MRF). Most recently, work has started on Hydrogen-3 Advanced Technology (H3AT) for tritium technology and a group of Fusion Technology Facilities.This article is part of a discussion meeting issue ‘Fusion energy using tokamaks: can development be accelerated?’

show abstract

Overview of recent physics results from MAST

Cited by 17 publications

References 88 publications

Velocity-space tomography using prior information at MAST

Velocity-space tomography using prior information at MAST

The effect of plasma shape and neutral beam mix on the rotation threshold for RMP-ELM suppression

UKAEA capabilities to address the challenges on the path to delivering fusion power

Contact Info

Product

Resources

About