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UKAEA-CCFE-PR(24)2162023
The first pedestal stability analysis on the new MAST Upgrade (MASTU) spherical tokamak H-mode plasma is presented. Our results indicate that MAST-U pedestals are close to the low toroidal mode number (n) peeling branch of the peelingballooning instability, in contrast with MAST H-mode pedestals which were deeply in the high-n ballooning branch. Th…
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UKAEA-CCFE-CP(23)632023
The real time plasma control system for the MAST Upgrade tokamak has been substantially redeveloped from its original MAST incarnation with a new architecture that aims to manage complexity whilst maximising flexibility. It provides modular layers of functionality and supports the implementation of virtual actuators to aggregate, arbitrate and rout…
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UKAEA-CCFE-PR(23)1592023
Fusion power output from spherical tokamaks would benefit from increased confined plasma density, but there exists a limit on the density before confinement is lost and the plasma current is disrupted. This density limit has long been characterized by a simple, global Greenwald limit proportional to the plasma current and inversely proportional …
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UKAEA-CCFE-CP(23)022023
Understanding the plasma parameters that affect the scrape off layer (SOL) width is a key issue for future tokamaks as the power entering the SOL (of order 100 MW [1] in ITER) and the SOL width (of order millimetres [2]) determine the heat flux to the divertor surfaces. The Eich scaling [2] can be used to characterise the divertor heat flux prof…
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UKAEA-CCFE-CP(24)062022
MAST-U is equipped with a Super-X divertor, which aims to reduce heat flux to the target and promote detachment. Measurements of plasma electron density and temperature in the Super-X chamber offer insight into the processes at work in this type of divertor. First data have been obtained from the MAST-U divertor Thomson scattering diagnostic design…
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UKAEA-CCFE-CP(24)052022
A new Doppler backscattering (DBS) system has been installed and tested on the MAST-U spherical tokamak. It utilizes eight simultaneous fixed frequency probe beams (32.5, 35, 37.5, 40, 42.5, 45, 47.5, and 50 GHz). These frequencies provide a range of radial positions from the edge plasma to the core depending on plasma conditions. The system utiliz…
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UKAEA-CCFE-CP(23)432022
MAST Upgrade (MAST-U) is a new low aspect ratio device (R/a = 0.85/0.65 ~ 1.3) based on the MAST tokamak that started plasma operations in October 2020. It has substantial new capabilities compared with the original MAST device, with 19 new poloidal field coils (14 of which are within the vacuum vessel) and new, closed, up-down symmetric diverto…
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UKAEA-CCFE-CP(23)412022
The MAST-U spherical tokamak has extensive capabilities to produce and explore strongly shaped plasmas and alternative divertor configurations, especially the Super-X. Robust and accurate reconstructions of plasma equilibria are the foundation of many physics analyses, as well as being important intershot for informing operation of the tokamak. …
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UKAEA-CCFE-PR(22)862022
Doppler reflectometry, or the Doppler backscattering (DBS) diagnostic, enables the measurement of turbulent density fluctuations of intermediate length scales, typically $10 gtrsim k_perp rho_i gtrsim 1$; here $k_perp$ is the turbulence’s wavenumber and $rho_i$ is the ion gyroradius. The backscattered power is proportional to the power of the tur…
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UKAEA-CCFE-PR(22)522022
Thomson scattered light is polarised in the same orientation as the incident laser beam at low electron temperatures. At high temperatures (>~4keV) part of the spectrum begins to become randomly polarised. First measurement of the depolarised Thomson scattering spectrum during were obtained from JET pulses 92038-92504. This paper builds upon …
Showing 1 - 10 of 63 UKAEA Paper Results