ELM sputter erosion modeling of a tungsten coated small angle slot divertor in DIII-D

Autor: J.N. Brooks, T. Sizyuk, G. Sinclair, T. Abrams, A. Hassanein
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: Nuclear Fusion, Vol 63, Iss 2, p 026032 (2023)
Druh dokumentu: article
ISSN: 1741-4326
0029-5515
DOI: 10.1088/1741-4326/acaf3a
Popis: We modeled plasma edge localized mode (ELM) sputter erosion for a Small Angle Slot divertor with a tungsten coated region (SAS-VW), designed for experiments in the DIII-D tokamak, and proposed for use in future advanced tokamaks. The simulations use a free-streaming, 1000 eV, C ^+6 and D ^+1 ELM impingement model, with SOLPS-ITER, ITMC-DYN, and REDEP/WBC code packages for background plasma, material response, and erosion/redeposition respectively. The results show ELM’ing plasma gross and net tungsten erosion fluxes of the mixed-material C/W surface peaking at the slot entrance region, and an order of magnitude higher than for non-ELMs. The per-pulse erosion, however, remains low, of order 0.5 nm, due to expected moderate ELM frequencies and duration in DIII-D. The ELMs result in a ∼25 x higher peak sputtered W current leaving the divertor slot region, towards the core plasma, compared to the ELM-free plasma case. The time-integrated escape current, however, may not significantly affect core plasma high-Z contamination concerns, for a 1% ELM duty factor, but may be an issue for higher frequency ELMs. In general, the modeling results appear favorable for effective testing of the SAS-VW divertor in DIII-D, and extrapolation to innovative divertor designs in future ITER-like and DEMO fusion devices.
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