Nanostructure formation and D retention in redeposited-like W exposed to linear plasmas
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 investigat...
| Main Authors: | , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2023-09-01
|
| Series: | Nuclear Materials and Energy |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S235217912300131X |
| _version_ | 1797679461988040704 |
|---|---|
| author | D. Dellasega G. Alberti E. Fortuna-Zalesna W. Zielinski A. Pezzoli S. Möller B. Unterberg M. Passoni A. Hakola |
| author_facet | D. Dellasega G. Alberti E. Fortuna-Zalesna W. Zielinski A. Pezzoli S. Möller B. Unterberg M. Passoni A. Hakola |
| author_sort | D. Dellasega |
| collection | DOAJ |
| description | 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 × 1025 D/m2 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. |
| first_indexed | 2024-03-11T23:15:01Z |
| format | Article |
| id | doaj.art-e604e7d1ccab4604abd49165b490b1e4 |
| institution | Directory Open Access Journal |
| issn | 2352-1791 |
| language | English |
| last_indexed | 2024-03-11T23:15:01Z |
| publishDate | 2023-09-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Nuclear Materials and Energy |
| spelling | doaj.art-e604e7d1ccab4604abd49165b490b1e42023-09-21T04:37:05ZengElsevierNuclear Materials and Energy2352-17912023-09-0136101492Nanostructure formation and D retention in redeposited-like W exposed to linear plasmasD. Dellasega0G. Alberti1E. Fortuna-Zalesna2W. Zielinski3A. Pezzoli4S. Möller5B. Unterberg6M. Passoni7A. Hakola8Department of Energy, Politecnico di Milano, Milan, Italy; Istituto per la Scienza e Tecnologia dei Plasmi, CNR, Milan, Italy; Corresponding author.Department of Energy, Politecnico di Milano, Milan, ItalyFaculty of Materials Science and Engineering, Warsaw University of Technology, Association EURATOM-IPPLM, Warsaw, PolandFaculty of Materials Science and Engineering, Warsaw University of Technology, Association EURATOM-IPPLM, Warsaw, PolandDepartment of Energy, Politecnico di Milano, Milan, ItalyForschungszentrum Jülich GmbH, Institut für Energie- und Klimaforschung—Plasmaphysik, Jülich, GermanyForschungszentrum Jülich GmbH, Institut für Energie- und Klimaforschung—Plasmaphysik, Jülich, GermanyDepartment of Energy, Politecnico di Milano, Milan, Italy; Istituto per la Scienza e Tecnologia dei Plasmi, CNR, Milan, ItalyVTT, P. O. Box 1000, 02044 VTT, FinlandDifferent 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 × 1025 D/m2 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.http://www.sciencedirect.com/science/article/pii/S235217912300131XRedeposited WNanostructure formationLinear machineD retention |
| spellingShingle | D. Dellasega G. Alberti E. Fortuna-Zalesna W. Zielinski A. Pezzoli S. Möller B. Unterberg M. Passoni A. Hakola Nanostructure formation and D retention in redeposited-like W exposed to linear plasmas Nuclear Materials and Energy Redeposited W Nanostructure formation Linear machine D retention |
| title | Nanostructure formation and D retention in redeposited-like W exposed to linear plasmas |
| title_full | Nanostructure formation and D retention in redeposited-like W exposed to linear plasmas |
| title_fullStr | Nanostructure formation and D retention in redeposited-like W exposed to linear plasmas |
| title_full_unstemmed | Nanostructure formation and D retention in redeposited-like W exposed to linear plasmas |
| title_short | Nanostructure formation and D retention in redeposited-like W exposed to linear plasmas |
| title_sort | nanostructure formation and d retention in redeposited like w exposed to linear plasmas |
| topic | Redeposited W Nanostructure formation Linear machine D retention |
| url | http://www.sciencedirect.com/science/article/pii/S235217912300131X |
| work_keys_str_mv | AT ddellasega nanostructureformationanddretentioninredepositedlikewexposedtolinearplasmas AT galberti nanostructureformationanddretentioninredepositedlikewexposedtolinearplasmas AT efortunazalesna nanostructureformationanddretentioninredepositedlikewexposedtolinearplasmas AT wzielinski nanostructureformationanddretentioninredepositedlikewexposedtolinearplasmas AT apezzoli nanostructureformationanddretentioninredepositedlikewexposedtolinearplasmas AT smoller nanostructureformationanddretentioninredepositedlikewexposedtolinearplasmas AT bunterberg nanostructureformationanddretentioninredepositedlikewexposedtolinearplasmas AT mpassoni nanostructureformationanddretentioninredepositedlikewexposedtolinearplasmas AT ahakola nanostructureformationanddretentioninredepositedlikewexposedtolinearplasmas |