Nanostructure formation and D retention in redeposited-like W exposed to linear plasmas
Publiceringsår
2023
Upphovspersoner
Dellasega, D.; Alberti, G.; Fortuna-Zalesna, E.; Zielinski, W.; Pezzoli, A.; Möller, S.; Unterberg, B.; Passoni, M.; Hakola, Antti
Abstrakt
<p>Different kinds of W layers resembling the ones found after campaigns in tokamak were produced by Pulsed Laser Deposition: namely nanocrystalline, amorphous and porous W layers. Films were exposed to divertor relevant D plasma, in PSI-2; D retention as well as nanostructure formation were investigated. For nanocrystalline W films we found lamellar structures that coalesce with increasing D fluence. Instead, on amorphous W no lamellas were formed but a new random string-like shape. A higher oxygen content in the W layer results in an evolution of the shape of the nanostructures in straight parallel lines with acute angles. The presence of a porous structure morphology hinders the formation of surface nanostructures. Reviewing results from different linear devices including also bulk W, we observe that, when formed, nanostructures appear in general with a fluence threshold of 3–5 × 10<sup>25</sup> D/m<sup>2</sup> regardless the impinging D flux. D retention shows an unusual trend increasing fluence and is enhanced by the presence of amorphous structure and open morphology. Amorphous W films exhibit higher D retention (3 orders of magnitude) compared to crystalline W. When the amorphous W is annealed, retention returns to the standard values of bulk W regardless the presence of a layered structure parallel to the substrate. Porous W, thanks to the high surface to volume ratio and the presence of void distribution along the growth direction, favors higher recycling and thus limits the D uptake during exposure. The presence of O, in the investigated coatings, seems to have little effect on D retention.</p>
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Publikationstyp
Publikationsform
Artikel
Moderpublikationens typ
Tidning
Artikelstyp
En originalartikel
Målgrupp
VetenskapligKollegialt utvärderad
Kollegialt utvärderadUKM:s publikationstyp
A1 Originalartikel i en vetenskaplig tidskriftPublikationskanalens uppgifter
Journal
Volym
36
Artikelnummer
101492
ISSN
Publikationsforum
Publikationsforumsnivå
1
Öppen tillgång
Öppen tillgänglighet i förläggarens tjänst
Ja
Öppen tillgång till publikationskanalen
Helt öppen publikationskanal
Licens för förläggarens version
CC BY
Parallellsparad
Nej
Övriga uppgifter
Vetenskapsområden
Fysik; Materialteknik
Nyckelord
[object Object],[object Object],[object Object],[object Object]
Språk
engelska
Internationell sampublikation
Ja
Sampublikation med ett företag
Nej
DOI
10.1016/j.nme.2023.101492
Publikationen ingår i undervisnings- och kulturministeriets datainsamling
Ja