Journal Article

FZJ-2022-04007

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Investigation of plasma wall interactions between tungsten plasma facing components and helium plasmas in the WEST tokamak

Tsitrone, E. ; Pegourie, B. ; Gunn, J. P. ; Bernard, E. ; Bruno, V. ; Corre, Y. ; Delpech, L. ; Diez, M. ; Douai, D. ; Ekedahl, A. ; Fedorczak, N. ; Gallo, A. ; Loarer, T. ; Vartanian, S. ; Gaspar, J. ; Le Bohec, M. ; Rigollet, F. ; Bisson, R. ; Brezinsek, S. (Corresponding author)FZJ* ; Dittmar, T.FZJ* ; De Temmerman, G. ; Hakola, A. ; Wauters, T. ; Balden, M. ; Mayer, M. ; WEST Team

2022
IAEA Vienna

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Please use a persistent id in citations: http://hdl.handle.net/2128/32236  doi:10.1088/1741-4326/ac2ef3

Abstract: ITER will operate with a tungsten divertor, a material featuring surface morphology changes when exposed to helium plasmas, in particular the formation of the so called tungsten fuzz under specific conditions. Investigating interactions between tungsten plasma facing components and helium plasmas in a tokamak environment is therefore a key point to consolidate predictions for the ITER divertor performance and lifetime. To this end, a dedicated helium campaign was performed in the full tungsten WEST tokamak, cumulating ∼2000 s of repetitive L mode discharges. It is shown that conditions for tungsten fuzz formation, as derived from linear devices experiments (incident helium energy Einc > 20 eV, helium fluence >1024 He/m2, surface temperature Tsurf > 700 °C), were met in the outer strike point (OSP) area of the inertially cooled tungsten divertor elements of WEST. Preliminary inspection of the components after the campaign did not show visible signs of surface modification, but points to significant net erosion in the OSP area. An extensive post mortem analysis is now ongoing to confirm these first indications. These results underline that the complex balance between erosion/redeposition (in particular linked to impurities) and tungsten fuzz formation needs to be taken into account in tokamak conditions.

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Contributing Institute(s):

1. Plasmaphysik (IEK-4)

Research Program(s):

1. 134 - Plasma-Wand-Wechselwirkung (POF4-134) (POF4-134)

Appears in the scientific report 2022

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Database coverage:
; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; Essential Science Indicators ; IF < 5 ; JCR ; National-Konsortium ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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