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UKAEA-CCFE-PR(26)4232025
The MAST Upgrade Super-X divertor protects plasma-facing components from heat fluxes during steady-state operation and transient events. This paper examines heat loads from sawtooth events with energies of ΔWsawtooth ≈ 2–9 kJ in lower single null plasmas. The impact of deuterium and nitrogen gas pressures on mitigating these transients is i…
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UKAEA-STEP-PR(26)012025
We have investigated the response of detached plasmas to multi-ms timescale power transients using 1D simulations of the scrape-off layer on a scale and parameter range relevant for reactor-scale tokamaks, such as the Spherical Tokamak for Energy Production (STEP). Simulations were performed using the fluid code Hermes3, employing the solver CVODE…
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UKAEA-CCFE-PR(25)3822025
The plasma energy and particle flows in double-null configurations during MAST L-mode discharges are investigated using the 3D plasma turbulence code STORM. The modelling reproduces key phenomena, such as in-out and up-down heat load asymmetries, despite not having a sophisticated neutral model. Turbulent energy transport, driven by ballooning-like…
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UKAEA-CCFE-PR(25)3312025
The effect of different D2 fueling locations and divertor closure in the MAST-U is studied in detail with the SOLPS-ITER code to gain insights to detachment physics in H-mode plasma experiments in conventional divertor (CD) configuration. The SOLPS-ITER simulations for MAST-U H-mode plasma reveals that changing D2 fueling location significantly i…
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UKAEA-CCFE-PR(25)3232025
SOLPS-ITER simulations of the ITER baseline ($Q=10$) plasma boundary, with tungsten (W) targets and drift terms activated, exhibit a radially localised peak in the energy flux density entering the outer divertor, despite constant anomalous transport coefficients across the scrape-off layer (SOL). This peak occurs radially beyond the near-SOL energy…
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UKAEA-STEP-PR(25)312024
A strategy to prevent concentrated deposition of the exhaust power in a fusion device is to seed a localised ‘divertor’ region with impurity gas, which is chosen to radiate predominantly at the cooler electron temperatures associated with the plasma edge. If this impurity travels upstream to the main confined plasma, it can significantly impact…
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UKAEA-CCFE-PR(25)3112024
2D electron density profiles obtained from coherence imaging spectroscopy in different MAST-U divertor conditions are compared. The data includes variations of strike point position, core electron density, and heating power. The improved performance of the long-legged divertors results in a lower electron density and particle flux at the target …
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UKAEA-CCFE-PR(25)2972024
During detachment, a buffer of neutral atoms and molecules builds up between the target and the ionising plasma. Collisions between the plasma and the molecules play an important role in the detachment process. Studies of plasma-molecular kinetics indicate that the gas temperature is increased during detachment for a wide range of conditions on …
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UKAEA-STEP-PR(24)182024
This paper presents a comprehensive overview of the preliminary divertor design and plasma exhaust scenario for the reactor-class Spherical Tokamak for Energy Production (STEP) project. Due to the smaller size of the machine, with a major radius less than half that of most DEMO concepts, the current design features a double-null divertor geometr…
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UKAEA-CCFE-CP(26)402023
A key objective of fusion research is to develop pathways to integrate good confinement in the core and pedestal with strong dissipation of power and particles in the divertor through a combination of experimental demonstration and modelling. The MAST Upgrade spherical tokamak has unique capabilities to find solutions to this integration challeng…
Showing 1 - 10 of 55 UKAEA Paper Results