Exploring the role of topography in the sputtering process of tungsten by GyM helium plasma

This work investigates the role of surface topography in the sputtering process of tungsten (W) exposed to helium plasma using the GyM linear device. Surfaces with varying roughness, from sub-nanometer to approximately 1 µ m, and different textures, including random-like and regular configurations,...

Full description

Saved in:
Bibliographic Details
Main Authors: Andrea Uccello, Gabriele Alberti, Matteo Pedroni, Anna Cremona, Francesco Ghezzi, Miriam Saleh, Espedito Vassallo, Luigi Bana, David Dellasega, Matteo Passoni, Carlo Tuccari, Davide Vavassori, Antti Hakola, Marcin Rasinski, Juri Romazanov, the GyM Team
Format: Article
Language:English
Published: IOP Publishing 2025-01-01
Series:Nuclear Fusion
Subjects:
Online Access:https://doi.org/10.1088/1741-4326/adc3aa
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850275950062731264
author Andrea Uccello
Gabriele Alberti
Matteo Pedroni
Anna Cremona
Francesco Ghezzi
Miriam Saleh
Espedito Vassallo
Luigi Bana
David Dellasega
Matteo Passoni
Carlo Tuccari
Davide Vavassori
Antti Hakola
Marcin Rasinski
Juri Romazanov
the GyM Team
author_facet Andrea Uccello
Gabriele Alberti
Matteo Pedroni
Anna Cremona
Francesco Ghezzi
Miriam Saleh
Espedito Vassallo
Luigi Bana
David Dellasega
Matteo Passoni
Carlo Tuccari
Davide Vavassori
Antti Hakola
Marcin Rasinski
Juri Romazanov
the GyM Team
author_sort Andrea Uccello
collection DOAJ
description This work investigates the role of surface topography in the sputtering process of tungsten (W) exposed to helium plasma using the GyM linear device. Surfaces with varying roughness, from sub-nanometer to approximately 1 µ m, and different textures, including random-like and regular configurations, were studied. The samples were exposed to helium plasma of GyM at energies ranging from 30 to 350 eV, with a fluence of ${\approx}4.3\times10^{24}$ He ^+ m ^−2 and temperatures well below the bulk W fuzz formation threshold of ≈700 ^∘ C. The interpretation of the experimental results was supported by simulations with the 3D Monte Carlo ERO2.0 code. Analysis with atomic force and scanning electron microscopy revealed that surface topography remained largely unchanged, while a nanoscale undulating surface structure formed on all samples at the highest incident energies. The effective sputtering yield ( $Y_{\mathrm{eff}}$ ) of tungsten, derived from mass and thickness loss data, was consistently lower than predictions from simulations by up to an order of magnitude, likely due to the dynamic retention of helium on the tungsten surface. On the other hand, both experimental results and modelling agree that surface topography’s influence on sputtering can be entirely captured by the average surface inclination angle ( $\delta_{\mathrm{m}}$ ), which unequivocally characterises each specimen, unlike the average roughness ( $R_{\mathrm{a}}$ ). Moreover, $Y_{\mathrm{eff}}$ values from both mass loss data and ERO2.0 simulations as a function of $\delta_{\mathrm{m}}$ align well with a decreasing sigmoid fit function. A reduction of more than 50% was observed when comparing the flat surface to that with the highest $R_{\mathrm{a}}$ , attributed by ERO2.0 to the increasing fraction of sputtered tungsten atoms being deposited on neighbouring surfaces. These findings underscore the importance of accurately calibrating simulation tools against linear plasma device experiments for predicting the lifetime of plasma-facing components in fusion reactors such as ITER and DEMO, emphasising the potential of structured tungsten surfaces to reduce erosion and impurity concentration in the plasma core.
format Article
id doaj-art-4170fe95763d4d0b81a0123b0fb984ca
institution OA Journals
issn 0029-5515
language English
publishDate 2025-01-01
publisher IOP Publishing
record_format Article
series Nuclear Fusion
spelling doaj-art-4170fe95763d4d0b81a0123b0fb984ca2025-08-20T01:50:30ZengIOP PublishingNuclear Fusion0029-55152025-01-0165505600610.1088/1741-4326/adc3aaExploring the role of topography in the sputtering process of tungsten by GyM helium plasmaAndrea Uccello0https://orcid.org/0000-0003-3044-1715Gabriele Alberti1https://orcid.org/0000-0001-9835-5085Matteo Pedroni2https://orcid.org/0000-0001-9391-1812Anna Cremona3https://orcid.org/0000-0001-8207-8597Francesco Ghezzi4https://orcid.org/0000-0003-3363-5187Miriam Saleh5https://orcid.org/0000-0001-5825-5012Espedito Vassallo6https://orcid.org/0000-0001-8435-4196Luigi Bana7https://orcid.org/0009-0003-1612-178XDavid Dellasega8https://orcid.org/0000-0002-7389-9307Matteo Passoni9https://orcid.org/0000-0002-7844-3691Carlo Tuccari10https://orcid.org/0009-0004-0144-5455Davide Vavassori11https://orcid.org/0000-0003-1279-3645Antti Hakola12https://orcid.org/0000-0003-1385-1296Marcin Rasinski13https://orcid.org/0000-0001-6277-4421Juri Romazanov14https://orcid.org/0000-0001-9439-786Xthe GyM TeamIstituto per la Scienza e Tecnologia dei Plasmi, CNR , 20125 Milan, ItalyDipartimento di Energia, Politecnico di Milano , 20133 Milan, ItalyIstituto per la Scienza e Tecnologia dei Plasmi, CNR , 20125 Milan, ItalyIstituto per la Scienza e Tecnologia dei Plasmi, CNR , 20125 Milan, ItalyIstituto per la Scienza e Tecnologia dei Plasmi, CNR , 20125 Milan, ItalyIstituto per la Scienza e Tecnologia dei Plasmi, CNR , 20125 Milan, ItalyIstituto per la Scienza e Tecnologia dei Plasmi, CNR , 20125 Milan, ItalyDipartimento di Energia, Politecnico di Milano , 20133 Milan, ItalyIstituto per la Scienza e Tecnologia dei Plasmi, CNR , 20125 Milan, Italy; Dipartimento di Energia, Politecnico di Milano , 20133 Milan, ItalyIstituto per la Scienza e Tecnologia dei Plasmi, CNR , 20125 Milan, Italy; Dipartimento di Energia, Politecnico di Milano , 20133 Milan, ItalyDipartimento di Energia, Politecnico di Milano , 20133 Milan, ItalyDipartimento di Energia, Politecnico di Milano , 20133 Milan, ItalyVTT Technical Research Centre of Finland Ltd , PO Box 1000, Espoo FI-02044 VTT, FinlandForschungszentrum Jülich GmbH, Institut für Energie-und Klimaforschung-Plasmaphysik, Partner of the Trilateral Euregio Cluster (TEC) , 52425 Jülich, GermanyForschungszentrum Jülich GmbH, Institut für Energie-und Klimaforschung-Plasmaphysik, Partner of the Trilateral Euregio Cluster (TEC) , 52425 Jülich, GermanyThis work investigates the role of surface topography in the sputtering process of tungsten (W) exposed to helium plasma using the GyM linear device. Surfaces with varying roughness, from sub-nanometer to approximately 1 µ m, and different textures, including random-like and regular configurations, were studied. The samples were exposed to helium plasma of GyM at energies ranging from 30 to 350 eV, with a fluence of ${\approx}4.3\times10^{24}$ He ^+ m ^−2 and temperatures well below the bulk W fuzz formation threshold of ≈700 ^∘ C. The interpretation of the experimental results was supported by simulations with the 3D Monte Carlo ERO2.0 code. Analysis with atomic force and scanning electron microscopy revealed that surface topography remained largely unchanged, while a nanoscale undulating surface structure formed on all samples at the highest incident energies. The effective sputtering yield ( $Y_{\mathrm{eff}}$ ) of tungsten, derived from mass and thickness loss data, was consistently lower than predictions from simulations by up to an order of magnitude, likely due to the dynamic retention of helium on the tungsten surface. On the other hand, both experimental results and modelling agree that surface topography’s influence on sputtering can be entirely captured by the average surface inclination angle ( $\delta_{\mathrm{m}}$ ), which unequivocally characterises each specimen, unlike the average roughness ( $R_{\mathrm{a}}$ ). Moreover, $Y_{\mathrm{eff}}$ values from both mass loss data and ERO2.0 simulations as a function of $\delta_{\mathrm{m}}$ align well with a decreasing sigmoid fit function. A reduction of more than 50% was observed when comparing the flat surface to that with the highest $R_{\mathrm{a}}$ , attributed by ERO2.0 to the increasing fraction of sputtered tungsten atoms being deposited on neighbouring surfaces. These findings underscore the importance of accurately calibrating simulation tools against linear plasma device experiments for predicting the lifetime of plasma-facing components in fusion reactors such as ITER and DEMO, emphasising the potential of structured tungsten surfaces to reduce erosion and impurity concentration in the plasma core.https://doi.org/10.1088/1741-4326/adc3aaGyMlinear plasma devicetungstenhelium plasmasputteringtopography
spellingShingle Andrea Uccello
Gabriele Alberti
Matteo Pedroni
Anna Cremona
Francesco Ghezzi
Miriam Saleh
Espedito Vassallo
Luigi Bana
David Dellasega
Matteo Passoni
Carlo Tuccari
Davide Vavassori
Antti Hakola
Marcin Rasinski
Juri Romazanov
the GyM Team
Exploring the role of topography in the sputtering process of tungsten by GyM helium plasma
Nuclear Fusion
GyM
linear plasma device
tungsten
helium plasma
sputtering
topography
title Exploring the role of topography in the sputtering process of tungsten by GyM helium plasma
title_full Exploring the role of topography in the sputtering process of tungsten by GyM helium plasma
title_fullStr Exploring the role of topography in the sputtering process of tungsten by GyM helium plasma
title_full_unstemmed Exploring the role of topography in the sputtering process of tungsten by GyM helium plasma
title_short Exploring the role of topography in the sputtering process of tungsten by GyM helium plasma
title_sort exploring the role of topography in the sputtering process of tungsten by gym helium plasma
topic GyM
linear plasma device
tungsten
helium plasma
sputtering
topography
url https://doi.org/10.1088/1741-4326/adc3aa
work_keys_str_mv AT andreauccello exploringtheroleoftopographyinthesputteringprocessoftungstenbygymheliumplasma
AT gabrielealberti exploringtheroleoftopographyinthesputteringprocessoftungstenbygymheliumplasma
AT matteopedroni exploringtheroleoftopographyinthesputteringprocessoftungstenbygymheliumplasma
AT annacremona exploringtheroleoftopographyinthesputteringprocessoftungstenbygymheliumplasma
AT francescoghezzi exploringtheroleoftopographyinthesputteringprocessoftungstenbygymheliumplasma
AT miriamsaleh exploringtheroleoftopographyinthesputteringprocessoftungstenbygymheliumplasma
AT espeditovassallo exploringtheroleoftopographyinthesputteringprocessoftungstenbygymheliumplasma
AT luigibana exploringtheroleoftopographyinthesputteringprocessoftungstenbygymheliumplasma
AT daviddellasega exploringtheroleoftopographyinthesputteringprocessoftungstenbygymheliumplasma
AT matteopassoni exploringtheroleoftopographyinthesputteringprocessoftungstenbygymheliumplasma
AT carlotuccari exploringtheroleoftopographyinthesputteringprocessoftungstenbygymheliumplasma
AT davidevavassori exploringtheroleoftopographyinthesputteringprocessoftungstenbygymheliumplasma
AT anttihakola exploringtheroleoftopographyinthesputteringprocessoftungstenbygymheliumplasma
AT marcinrasinski exploringtheroleoftopographyinthesputteringprocessoftungstenbygymheliumplasma
AT juriromazanov exploringtheroleoftopographyinthesputteringprocessoftungstenbygymheliumplasma
AT thegymteam exploringtheroleoftopographyinthesputteringprocessoftungstenbygymheliumplasma