OEDGE modeling of far-SOL tungsten impurity sources and screening in WEST

Autor: J.B. Maeker, J.H. Nichols, D.C. Donovan, A. Grosjean, J. Gunn, N. Fedorczak, C. Guillemaut, C.C. Klepper, E.A. Unterberg, D.C. Easley, WEST Team
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Nuclear Materials and Energy, Vol 33, Iss , Pp 101309- (2022)
Druh dokumentu: article
ISSN: 2352-1791
DOI: 10.1016/j.nme.2022.101309
Popis: The plasma background and impurity transport in the scrape-off layer (SOL) of the WEST tokamak are modeled for three discharges over a Psep power scan ranging between 1.5 and 2.35 MW. An extended modeling grid is used to investigate far-SOL sourcing from the WEST baffle and lower divertor. Divertor Langmuir probe data at the targets and upstream data from reciprocating Langmuir probes and interferometry/reflectometry is used to create a simulated background plasma with the OSM and EIRENE codes. W-I spectroscopic data from WEST at the lower divertor and baffle is used to estimate the sputtered W flux as an input to the impurity transport code DIVIMP. A potential mechanism for far-SOL impurities from the baffle to transport into the near-SOL is proposed and discussed in terms of the model’s force balances. Analysis of simulated impurity transport showed similar impurity density at the separatrix for the mid and high-power cases despite the high-power case having 10% more sputtered W. This is explained by the combination of differing trends in the sourcing and screening with scaling power.
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