Speaker
Description
Understanding the mechanism of edge transport in magnetic confinement fusion devices is critical for future reactors, as it determines how effectively high heat loads can be exhausted to achieve the sustainability of the devices.
In this work, the multi-fidelity exhaust code Hermes-3 [1] is employed to model scrape-off layer (SOL) transport using a fluid framework, solving the Braginskii equations [2] for the plasma and the advanced fluid equations for neutrals [3,4]. This approach contrasts with conventional exhaust modelling codes, such as SOLPS-ITER, which describe neutral transport kinetically at high computational cost. Replacing kinetic neutral models with fluid descriptions could accelerate simulations, whereas it is valid only in regions dominated by high charge-exchange collisions. Despite this limitation, fluid neutral models remain attractive due to their efficiency. This work compares fluid and kinetic treatments of neutral particles and assesses their impact on modelling in MAST-U.
[1] B.Dudson, M.Kryjak, H.Muhammed, P.Hill, J,Omotani Hermes-3: Multi-component plasma simulations with BOUT++ Comp. Phys. Comm. 2023 108991
[2] Braginskii S.I. 1965 Transport processes in a plasma Reviews of Plasma Physics vol 1
[3] W. Van Uytven, et. al. ‘Assessment of advanced fluid neutral models for the neutral atoms in the plasma edge and application in ITER geometry’, Nucl. Fusion, vol. 62, no. 8, p. 086023, June 2022
[4] et. al. N. Horsten, ‘Development and assessment of 2D fluid neutral models that include atomic databases and a microscopic reflection model’, Nucl. Fusion, vol. 57, no. 11, p. 116043, Aug. 2017