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UKAEA-CCFE-PR(25)2702024
Pellets of frozen material travelling into a magnetically confined fusion plasma are accelerated by the so-called pellet rocket effect. The non-uniform plasma heats the pellet ablation cloud asymmetrically, producing pressure-driven, rocket-like propulsion of the pellet. We present a semi-analytical model of this process by perturbing a spherica…
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UKAEA-CCFE-PR(25)2712024
We detail here a semi-analytical model for the pellet rocket effect, which describes the acceleration of pellets in a fusion plasma due to asymmetries in the heat flux reaching the pellet surface and the corresponding ablation rate. This effect was shown in experiments to significantly modify the pellet trajectory, and projections for reactor sc…
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UKAEA-STEP-PR(25)252024
This paper discusses the importance of parallel and perpendicular magnetic field perturbations in gyrokinetic simulations of electromagnetic instabilities and turbulence at mid-radius in the burning plasma phase of the conceptual high-β, reactor-scale, tight-aspect- ratio tokamak STEP. Previous studies have revealed the presence of unstable hybrid…
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UKAEA-CCFE-PR(25)2642023
Advances in edge and scrape-off layer diagnostics have shown that often the ion temperature is higher than the electron temperature in scrape-off layer filaments. We have therefore extended the STORM model beyond the cold ion limit commonly used, to include hot ion effects. We find that filaments are both faster and more coherent than in a cold …
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UKAEA-STEP-PR(25)242024
The UKAEA’s Spherical Tokamak for Energy Production (STEP) programme aims to demonstrate the ability of low aspect ratio tokamaks to generate net electricity from deuterium-tritium (DT) fusion. As STEP have selected REBCO coated conductor (CC) as the current carrier in most magnet systems, understanding how REBCO CC responds to the energetic p…
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UKAEA-STEP-PR(25)232023
The purpose of this work was to establish an approach to drive the development, at pace, of a commercially relevant Spherical Tokamak Concept. Building on the table of parameters and idealised geometry generated from the work of S. Muldrew et al [1], applying core principles, tools, and approaches. The generation and utilisation of a reflective …
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UKAEA-RACE-PR(25)012024
Robotics holds the potential to streamline the execution of repetitive and dangerous tasks, which are difficult or impossible for a human operator. However, in complex scenarios, such as nuclear waste management or disaster response, full automation often proves unfeasible due to the diverse and intricate nature of tasks, coupled with unpredicta…
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UKAEA-CCFE-PR(24)2622023
STORM is a plasma turbulence code capable of simulating 3d turbulence across the full scrape-off layer of a tokamak fusion reactor, using a drift reduced, collisional fluid model. STORM uses mostly finite difference schemes, with a staggered grid in the direction parallel to the magnetic field. We describe the model, geometry and initialisation opt…
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UKAEA-CCFE-PR(24)2562024
An absolutely calibrated, visible imaging diagnostic has been deployed on the MAST spherical tokamak. Two sets of three colour channels are defined using a combination of stacked multi-cavity interference filters, colour-glass filter and a colour-pixel sensor. The system is compact with a single viewing pupil which facilitates unambiguous compariso…
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UKAEA-CCFE-PR(24)2632024
Originally designed for five years of plasma operations, the JET Far Infrared (FIR) interferometer/polarimeter diagnostic system is still operating at its full capabilities nearly forty years later and in ITER relevant conditions, albeit with significantly lower neutron fluences and for several D-T campaigns. The original design changed substant…
Showing 231 - 240 of 2527 UKAEA Paper Results