Surface composition and morphology changes of JET tiles under plasma interactions

JET-EFDA collaborators

    Research output: Contribution to journalArticleScientificpeer-review

    3 Citations (Scopus)

    Abstract

    Plasma interactions with the main chamber of magnetic fusion devices result in net erosion from some areas and net deposition at other locations. However, high energy particle irradiation means that there are continuous erosion and re-deposition processes involved, creating new surface structures. Although the net deposition can be readily assessed, net erosion and material mixing is difficult to determine. In 2005 marker tiles were mounted in the JET vessel which have a thin tungsten (W) layer deposited on the CFC substrate with a ∼10 μm carbon layer on top. This layered structure was designed to determine the areas where some erosion had occurred during JET plasma operations, when the tiles were removed for analysis in 2007.

    This paper describes the results from a set of tiles mounted in a poloidal limiter (in Octant 8) at the outer wall of the main chamber; a comparison is made between the data from tiles near the top, middle and bottom of the limiter. A set of ion beam techniques together with electron microscopy were used to provide a detailed analysis of the tiles. In general, since plasma interaction is strongest near the centre of the limiter where the tile is closest to the boundary of the confined plasma, erosion dominated on the central tiles, with deposition further from the plasma boundary. Also the amount of retained deuterium is higher in the tiles located in the upper and lower regions of the plasma chamber.
    Original languageEnglish
    Pages (from-to)2557-2560
    Number of pages4
    JournalFusion Engineering and Design
    Volume86
    Issue number9-11
    DOIs
    Publication statusPublished - 2011
    MoE publication typeA1 Journal article-refereed
    Event26th Symposium of Fusion Technology, SOFT-26 - Porto, Portugal
    Duration: 27 Sep 20101 Oct 2010
    Conference number: 26

    Fingerprint

    Plasma interactions
    Tile
    Surface structure
    Surface morphology
    Erosion
    Limiters
    Plasmas
    Chlorofluorocarbons
    Deuterium
    Ion beams
    Electron microscopy
    Tungsten
    Fusion reactions
    Irradiation
    Carbon

    Keywords

    • Ion beam analysis
    • Carbon fibre composites tiles
    • Fusion reactor materials

    Cite this

    JET-EFDA collaborators. / Surface composition and morphology changes of JET tiles under plasma interactions. In: Fusion Engineering and Design. 2011 ; Vol. 86, No. 9-11. pp. 2557-2560.
    @article{b0707528f8424b399ca61cafcb061951,
    title = "Surface composition and morphology changes of JET tiles under plasma interactions",
    abstract = "Plasma interactions with the main chamber of magnetic fusion devices result in net erosion from some areas and net deposition at other locations. However, high energy particle irradiation means that there are continuous erosion and re-deposition processes involved, creating new surface structures. Although the net deposition can be readily assessed, net erosion and material mixing is difficult to determine. In 2005 marker tiles were mounted in the JET vessel which have a thin tungsten (W) layer deposited on the CFC substrate with a ∼10 μm carbon layer on top. This layered structure was designed to determine the areas where some erosion had occurred during JET plasma operations, when the tiles were removed for analysis in 2007.This paper describes the results from a set of tiles mounted in a poloidal limiter (in Octant 8) at the outer wall of the main chamber; a comparison is made between the data from tiles near the top, middle and bottom of the limiter. A set of ion beam techniques together with electron microscopy were used to provide a detailed analysis of the tiles. In general, since plasma interaction is strongest near the centre of the limiter where the tile is closest to the boundary of the confined plasma, erosion dominated on the central tiles, with deposition further from the plasma boundary. Also the amount of retained deuterium is higher in the tiles located in the upper and lower regions of the plasma chamber.",
    keywords = "Ion beam analysis, Carbon fibre composites tiles, Fusion reactor materials",
    author = "Alves, {L. C.} and E. Alves and Barradas, {N. P.} and M. Dias and R. Mateus and P. Carvalho and Coad, {J. P.} and Widdowson, {A. M.} and Jari Likonen and Seppo Koivuranta and {JET-EFDA collaborators}",
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    language = "English",
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    pages = "2557--2560",
    journal = "Fusion Engineering and Design",
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    }

    Surface composition and morphology changes of JET tiles under plasma interactions. / JET-EFDA collaborators.

    In: Fusion Engineering and Design, Vol. 86, No. 9-11, 2011, p. 2557-2560.

    Research output: Contribution to journalArticleScientificpeer-review

    TY - JOUR

    T1 - Surface composition and morphology changes of JET tiles under plasma interactions

    AU - Alves, L. C.

    AU - Alves, E.

    AU - Barradas, N. P.

    AU - Dias, M.

    AU - Mateus, R.

    AU - Carvalho, P.

    AU - Coad, J. P.

    AU - Widdowson, A. M.

    AU - Likonen, Jari

    AU - Koivuranta, Seppo

    AU - JET-EFDA collaborators

    PY - 2011

    Y1 - 2011

    N2 - Plasma interactions with the main chamber of magnetic fusion devices result in net erosion from some areas and net deposition at other locations. However, high energy particle irradiation means that there are continuous erosion and re-deposition processes involved, creating new surface structures. Although the net deposition can be readily assessed, net erosion and material mixing is difficult to determine. In 2005 marker tiles were mounted in the JET vessel which have a thin tungsten (W) layer deposited on the CFC substrate with a ∼10 μm carbon layer on top. This layered structure was designed to determine the areas where some erosion had occurred during JET plasma operations, when the tiles were removed for analysis in 2007.This paper describes the results from a set of tiles mounted in a poloidal limiter (in Octant 8) at the outer wall of the main chamber; a comparison is made between the data from tiles near the top, middle and bottom of the limiter. A set of ion beam techniques together with electron microscopy were used to provide a detailed analysis of the tiles. In general, since plasma interaction is strongest near the centre of the limiter where the tile is closest to the boundary of the confined plasma, erosion dominated on the central tiles, with deposition further from the plasma boundary. Also the amount of retained deuterium is higher in the tiles located in the upper and lower regions of the plasma chamber.

    AB - Plasma interactions with the main chamber of magnetic fusion devices result in net erosion from some areas and net deposition at other locations. However, high energy particle irradiation means that there are continuous erosion and re-deposition processes involved, creating new surface structures. Although the net deposition can be readily assessed, net erosion and material mixing is difficult to determine. In 2005 marker tiles were mounted in the JET vessel which have a thin tungsten (W) layer deposited on the CFC substrate with a ∼10 μm carbon layer on top. This layered structure was designed to determine the areas where some erosion had occurred during JET plasma operations, when the tiles were removed for analysis in 2007.This paper describes the results from a set of tiles mounted in a poloidal limiter (in Octant 8) at the outer wall of the main chamber; a comparison is made between the data from tiles near the top, middle and bottom of the limiter. A set of ion beam techniques together with electron microscopy were used to provide a detailed analysis of the tiles. In general, since plasma interaction is strongest near the centre of the limiter where the tile is closest to the boundary of the confined plasma, erosion dominated on the central tiles, with deposition further from the plasma boundary. Also the amount of retained deuterium is higher in the tiles located in the upper and lower regions of the plasma chamber.

    KW - Ion beam analysis

    KW - Carbon fibre composites tiles

    KW - Fusion reactor materials

    U2 - 10.1016/j.fusengdes.2011.03.093

    DO - 10.1016/j.fusengdes.2011.03.093

    M3 - Article

    VL - 86

    SP - 2557

    EP - 2560

    JO - Fusion Engineering and Design

    JF - Fusion Engineering and Design

    SN - 0920-3796

    IS - 9-11

    ER -