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UKAEA-CCFE-PR(19)672019
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…
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UKAEA-CCFE-PR(19)552019
In ITER and DEMO, achieving detachment at lower densities would allow to reduce the amount of impurity seeded and to improve confinement by running at lower separatrix densities. Analytic models predict that a increase of total flux expansion would allow such a reduction in upstream density at detachment. However, both experiments and modelling …
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UKAEA-CCFE-PR(19)462019
The effect of plasma shaping on scrape-off layer (SOL) plasma turbulence is investigated through a rigorous validation exercise. Two- and three-dimensional simulations of the SOL plasma dynamics in three TCV limited discharges are carried out with the GBS code. These discharges realize an almost circular magnetic equilibrium, an elongated equilibri…
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UKAEA-RACE-PR(19)012019
Systems Engineering (SE) allows addressing the design of complex systems from a holistic standpoint, starting from the early stage of development until the end of its lifetime. Using a SE approach, all the stakeholders’ needs can be considered, and different design alternatives can be proposed, taking into account requirements coming from all the…
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UKAEA-CCFE-PR(19)282019
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…
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UKAEA-CCFE-PR(19)162019
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…
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UKAEA-CCFE-CP(18)102018
Recent experiments on Magnum-PSI exposed a lithium-filled heat pipe to a hydrogen plasma beam to demonstrate the potential of radiatively cooled, high temperature heat pipes as modular, replaceable plasma facing components. Monitoring the temperature distribution over the full 20cm length of the pipe was a crucial element of the experiment, requiri…
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UKAEA-CCFE-CP(18)052018
Pellets are used in ASDEX Upgrade [1] to control plasma density under conditions of ELM control or divertor detachment. In experiments presented here direct fuelling by gas is negligible. Relative pellet size and pellet deposition are aimed to approach those in ITER but differences still remain. ELMs are controlled by n=2 RMPs in feed forward mode …
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UKAEA-CCFE-CP(18)042018
An edge resonant transport layer has been found to explain many aspects of fast-ion confinement under symmetry breaking 3D edge perturbations, such as edge localized modes (ELMs) and externally applied magnetic perturbations (MPs). Experimental measurements in the ASDEX Upgrade (AUG) tokamak show that fast-ion losses in the presence of symmetry bre…
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UKAEA-CCFE-CP(19)162018
Edge Localised Modes (ELMs) in H-mode tokamak plasmas may be controlled or entirely suppressed by applying 3D magnetic perturbations (MPs). The applied perturbation is amplified by the plasma response, and it has previously been established that the size of the peeling component of this response is a reliable indicator for expected ELM control on A…
Showing 91 - 100 of 234 UKAEA Paper Results