Long-term erosion of plasma-facing materials with different surface roughness in ASDEX Upgrade

Antti Hakola; Juuso Karhunen; Seppo Koivuranta; Jari Likonen; M. Balden; A. Herrmann; M. Mayer; H.W. Müller; R. Neu; V. Rohde; K. Sugiyama; ASDEX Upgrade Team

doi:10.1088/0031-8949/2014/T159/014027

Long-term erosion of plasma-facing materials with different surface roughness in ASDEX Upgrade

Antti Hakola (Corresponding Author), Juuso Karhunen, Seppo Koivuranta, Jari Likonen, M. Balden, A. Herrmann, M. Mayer, H.W. Müller, R. Neu, V. Rohde, K. Sugiyama, ASDEX Upgrade Team

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Abstract

The effect of surface roughness on the long-term erosion patterns of tungsten coatings was investigated in the outer strike-point region of ASDEX Upgrade during its 2010–11 plasma operations. The net erosion rates of rough coatings (Ra = 5–6 μm) were three to seven times smaller than those of smooth coatings (Ra = 0.4–0.8 μm). This is because rough surfaces are largely modified and damaged in the microscopic scale but the material is re-deposited together with boron, deuterium and carbon on the shadowed sides of the most prominent surface features. In addition, we observed that W coatings were eroded on average at a rate of 0.03 nm s−1, which was three to four times smaller than the value for Cr, simulating here steel.

Original language	English
Article number	014027
Number of pages	5
Journal	Physica Scripta
Issue number	T159
DOIs	https://doi.org/10.1088/0031-8949/2014/T159/014027
Publication status	Published - 2014
MoE publication type	A1 Journal article-refereed
Event	14th International conference on plasma-facing materials and components for fusion applications: PFMC-14 - Jülich, Germany Duration: 13 May 2013 → 17 May 2013

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title = "Long-term erosion of plasma-facing materials with different surface roughness in ASDEX Upgrade",

abstract = "The effect of surface roughness on the long-term erosion patterns of tungsten coatings was investigated in the outer strike-point region of ASDEX Upgrade during its 2010–11 plasma operations. The net erosion rates of rough coatings (Ra = 5–6 μm) were three to seven times smaller than those of smooth coatings (Ra = 0.4–0.8 μm). This is because rough surfaces are largely modified and damaged in the microscopic scale but the material is re-deposited together with boron, deuterium and carbon on the shadowed sides of the most prominent surface features. In addition, we observed that W coatings were eroded on average at a rate of 0.03 nm s−1, which was three to four times smaller than the value for Cr, simulating here steel.",

author = "Antti Hakola and Juuso Karhunen and Seppo Koivuranta and Jari Likonen and M. Balden and A. Herrmann and M. Mayer and H.W. M{\"u}ller and R. Neu and V. Rohde and K. Sugiyama and {ASDEX Upgrade Team}",

note = "Project code: 85724 ; 14th International conference on plasma-facing materials and components for fusion applications : PFMC-14, PFMC-14 ; Conference date: 13-05-2013 Through 17-05-2013",

year = "2014",

doi = "10.1088/0031-8949/2014/T159/014027",

language = "English",

journal = "Physica Scripta",

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TY - JOUR

T1 - Long-term erosion of plasma-facing materials with different surface roughness in ASDEX Upgrade

AU - Hakola, Antti

AU - Karhunen, Juuso

AU - Koivuranta, Seppo

AU - Likonen, Jari

AU - Balden, M.

AU - Herrmann, A.

AU - Mayer, M.

AU - Müller, H.W.

AU - Neu, R.

AU - Rohde, V.

AU - Sugiyama, K.

AU - ASDEX Upgrade Team

N1 - Project code: 85724

PY - 2014

Y1 - 2014

N2 - The effect of surface roughness on the long-term erosion patterns of tungsten coatings was investigated in the outer strike-point region of ASDEX Upgrade during its 2010–11 plasma operations. The net erosion rates of rough coatings (Ra = 5–6 μm) were three to seven times smaller than those of smooth coatings (Ra = 0.4–0.8 μm). This is because rough surfaces are largely modified and damaged in the microscopic scale but the material is re-deposited together with boron, deuterium and carbon on the shadowed sides of the most prominent surface features. In addition, we observed that W coatings were eroded on average at a rate of 0.03 nm s−1, which was three to four times smaller than the value for Cr, simulating here steel.

AB - The effect of surface roughness on the long-term erosion patterns of tungsten coatings was investigated in the outer strike-point region of ASDEX Upgrade during its 2010–11 plasma operations. The net erosion rates of rough coatings (Ra = 5–6 μm) were three to seven times smaller than those of smooth coatings (Ra = 0.4–0.8 μm). This is because rough surfaces are largely modified and damaged in the microscopic scale but the material is re-deposited together with boron, deuterium and carbon on the shadowed sides of the most prominent surface features. In addition, we observed that W coatings were eroded on average at a rate of 0.03 nm s−1, which was three to four times smaller than the value for Cr, simulating here steel.

U2 - 10.1088/0031-8949/2014/T159/014027

DO - 10.1088/0031-8949/2014/T159/014027

M3 - Article

JO - Physica Scripta

JF - Physica Scripta

SN - 0031-8949

IS - T159

M1 - 014027

T2 - 14th International conference on plasma-facing materials and components for fusion applications

Y2 - 13 May 2013 through 17 May 2013

ER -

Long-term erosion of plasma-facing materials with different surface roughness in ASDEX Upgrade

Abstract

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