Overview of the second stage in the comprehensive mirrors test in JET

JET-EFDA collaborators

    Research output: Contribution to journalArticleScientificpeer-review

    14 Citations (Scopus)

    Abstract

    The first mirror test for ITER in JET with carbon walls has been completed. Thirty polycrystalline Mo mirrors including four coated with a 1 μm rhodium (Rh) film were exposed to plasma in the divertor region and in the main chamber. The mirrors were installed in eight cassettes of pan-pipe shape. The reflectivity of all mirrors exposed in the divertor has been degraded by 80–90% because of the formation of thick (>20 μm) flaking co-deposits on surfaces. Only small reflectivity losses (5–10%) occurred on mirrors located at the channel mouth of the cassettes from the main chamber wall. This is due to the in situ removal of deposited species by charge exchange neutrals. Deuterium, 12C and 9Be are the main isotopes detected on surfaces, but other isotopes (13C) are also found in some locations, thus indicating differences in the material migration. Rhodium coatings with an initial reflectivity that is 30% better than that of pure Mo survived the test without detachment, but their resultant reflectivity was the same as that of the exposed Mo surfaces.
    Original languageEnglish
    Article number014070
    Number of pages6
    JournalPhysica Scripta
    Issue numberT145
    DOIs
    Publication statusPublished - 2011
    MoE publication typeA1 Journal article-refereed
    Event13th International Workshop on Plasma-Facing Materials and Components for Fusion Applications, PFMC-13 - Rosenheim, Germany
    Duration: 9 May 201113 May 2011

    Fingerprint

    Reflectivity
    Mirror
    mirrors
    reflectance
    rhodium
    isotopes
    chambers
    flaking
    mouth
    detachment
    charge exchange
    Coating
    Migration
    deuterium
    Carbon
    Plasma
    deposits
    Charge
    coatings
    carbon

    Cite this

    @article{6eeac83dd2104a848653321cf8d43c44,
    title = "Overview of the second stage in the comprehensive mirrors test in JET",
    abstract = "The first mirror test for ITER in JET with carbon walls has been completed. Thirty polycrystalline Mo mirrors including four coated with a 1 μm rhodium (Rh) film were exposed to plasma in the divertor region and in the main chamber. The mirrors were installed in eight cassettes of pan-pipe shape. The reflectivity of all mirrors exposed in the divertor has been degraded by 80–90{\%} because of the formation of thick (>20 μm) flaking co-deposits on surfaces. Only small reflectivity losses (5–10{\%}) occurred on mirrors located at the channel mouth of the cassettes from the main chamber wall. This is due to the in situ removal of deposited species by charge exchange neutrals. Deuterium, 12C and 9Be are the main isotopes detected on surfaces, but other isotopes (13C) are also found in some locations, thus indicating differences in the material migration. Rhodium coatings with an initial reflectivity that is 30{\%} better than that of pure Mo survived the test without detachment, but their resultant reflectivity was the same as that of the exposed Mo surfaces.",
    author = "M. Rubel and D. Ivanova and J.P. Coad and {De Temmerman}, G. and Jari Likonen and L. Marot and A. Schmidt and A. Widdowson and {JET-EFDA collaborators}",
    year = "2011",
    doi = "10.1088/0031-8949/2011/T145/014070",
    language = "English",
    journal = "Physica Scripta",
    issn = "0031-8949",
    publisher = "Institute of Physics IOP",
    number = "T145",

    }

    Overview of the second stage in the comprehensive mirrors test in JET. / JET-EFDA collaborators.

    In: Physica Scripta, No. T145, 014070, 2011.

    Research output: Contribution to journalArticleScientificpeer-review

    TY - JOUR

    T1 - Overview of the second stage in the comprehensive mirrors test in JET

    AU - Rubel, M.

    AU - Ivanova, D.

    AU - Coad, J.P.

    AU - De Temmerman, G.

    AU - Likonen, Jari

    AU - Marot, L.

    AU - Schmidt, A.

    AU - Widdowson, A.

    AU - JET-EFDA collaborators

    PY - 2011

    Y1 - 2011

    N2 - The first mirror test for ITER in JET with carbon walls has been completed. Thirty polycrystalline Mo mirrors including four coated with a 1 μm rhodium (Rh) film were exposed to plasma in the divertor region and in the main chamber. The mirrors were installed in eight cassettes of pan-pipe shape. The reflectivity of all mirrors exposed in the divertor has been degraded by 80–90% because of the formation of thick (>20 μm) flaking co-deposits on surfaces. Only small reflectivity losses (5–10%) occurred on mirrors located at the channel mouth of the cassettes from the main chamber wall. This is due to the in situ removal of deposited species by charge exchange neutrals. Deuterium, 12C and 9Be are the main isotopes detected on surfaces, but other isotopes (13C) are also found in some locations, thus indicating differences in the material migration. Rhodium coatings with an initial reflectivity that is 30% better than that of pure Mo survived the test without detachment, but their resultant reflectivity was the same as that of the exposed Mo surfaces.

    AB - The first mirror test for ITER in JET with carbon walls has been completed. Thirty polycrystalline Mo mirrors including four coated with a 1 μm rhodium (Rh) film were exposed to plasma in the divertor region and in the main chamber. The mirrors were installed in eight cassettes of pan-pipe shape. The reflectivity of all mirrors exposed in the divertor has been degraded by 80–90% because of the formation of thick (>20 μm) flaking co-deposits on surfaces. Only small reflectivity losses (5–10%) occurred on mirrors located at the channel mouth of the cassettes from the main chamber wall. This is due to the in situ removal of deposited species by charge exchange neutrals. Deuterium, 12C and 9Be are the main isotopes detected on surfaces, but other isotopes (13C) are also found in some locations, thus indicating differences in the material migration. Rhodium coatings with an initial reflectivity that is 30% better than that of pure Mo survived the test without detachment, but their resultant reflectivity was the same as that of the exposed Mo surfaces.

    U2 - 10.1088/0031-8949/2011/T145/014070

    DO - 10.1088/0031-8949/2011/T145/014070

    M3 - Article

    JO - Physica Scripta

    JF - Physica Scripta

    SN - 0031-8949

    IS - T145

    M1 - 014070

    ER -