Deuterium removal during thermo-oxidation of Be-containing codeposits from JET divertor tiles

C. K. Tsui, A. A. Haasz (Corresponding Author), J. W. Davis, J. P. Coad, Jari Likonen

    Research output: Contribution to journalArticleScientificpeer-review

    20 Citations (Scopus)

    Abstract

    This study focuses on the removal of trapped D from thick codeposits on JET divertor tiles via thermo-oxidation. The tiles were removed from the JET Mark II Gas Box divertor after the 1998–2001 campaign. These codeposits have Be concentrations of up to ~60% Be/(Be + C) and their thicknesses range from 10 to 270 µm. Laser thermal desorption spectroscopy was used to determine the D removal rates and final remaining D concentrations following oxidation. Estimates of the carbon removed during oxidation were obtained from mass-loss measurements. The initial rate of D removal was found to be much higher for the thick codeposits of this study than for the previously studied codeposits with thicknesses in the range 1–5 µm (from TFTR, DIII-D and JET). This is despite the large Be concentrations. For oxidation performed at 623 K (350 °C) and 21 kPa (160 Torr) O2 pressure the initial D removal rates were found to increase linearly with increasing 'inherent' D content; about 50% of the inherent D was removed from all specimens in the first 15 min—independent of Be content and codeposit thickness. Following 8 h of oxidation, the fraction of D removed was >85% for all specimens, again, independent of Be content and thickness.
    Original languageEnglish
    Article number035008
    Number of pages9
    JournalNuclear Fusion
    Volume48
    Issue number3
    DOIs
    Publication statusPublished - 2008
    MoE publication typeA1 Journal article-refereed

    Fingerprint

    tiles
    deuterium
    oxidation
    boxes
    desorption
    carbon
    estimates
    gases
    spectroscopy
    lasers

    Keywords

    • JET
    • divertor plasma
    • divertor tiles
    • fusion energy
    • fusion reactors
    • plasma
    • oxidation

    Cite this

    Tsui, C. K. ; Haasz, A. A. ; Davis, J. W. ; Coad, J. P. ; Likonen, Jari. / Deuterium removal during thermo-oxidation of Be-containing codeposits from JET divertor tiles. In: Nuclear Fusion. 2008 ; Vol. 48, No. 3.
    @article{821c30ed2d7b49a298d9bf6b29a8a9d0,
    title = "Deuterium removal during thermo-oxidation of Be-containing codeposits from JET divertor tiles",
    abstract = "This study focuses on the removal of trapped D from thick codeposits on JET divertor tiles via thermo-oxidation. The tiles were removed from the JET Mark II Gas Box divertor after the 1998–2001 campaign. These codeposits have Be concentrations of up to ~60{\%} Be/(Be + C) and their thicknesses range from 10 to 270 µm. Laser thermal desorption spectroscopy was used to determine the D removal rates and final remaining D concentrations following oxidation. Estimates of the carbon removed during oxidation were obtained from mass-loss measurements. The initial rate of D removal was found to be much higher for the thick codeposits of this study than for the previously studied codeposits with thicknesses in the range 1–5 µm (from TFTR, DIII-D and JET). This is despite the large Be concentrations. For oxidation performed at 623 K (350 °C) and 21 kPa (160 Torr) O2 pressure the initial D removal rates were found to increase linearly with increasing 'inherent' D content; about 50{\%} of the inherent D was removed from all specimens in the first 15 min—independent of Be content and codeposit thickness. Following 8 h of oxidation, the fraction of D removed was >85{\%} for all specimens, again, independent of Be content and thickness.",
    keywords = "JET, divertor plasma, divertor tiles, fusion energy, fusion reactors, plasma, oxidation",
    author = "Tsui, {C. K.} and Haasz, {A. A.} and Davis, {J. W.} and Coad, {J. P.} and Jari Likonen",
    year = "2008",
    doi = "10.1088/0029-5515/48/3/035008",
    language = "English",
    volume = "48",
    journal = "Nuclear Fusion",
    issn = "0029-5515",
    publisher = "Institute of Physics IOP",
    number = "3",

    }

    Deuterium removal during thermo-oxidation of Be-containing codeposits from JET divertor tiles. / Tsui, C. K.; Haasz, A. A. (Corresponding Author); Davis, J. W.; Coad, J. P.; Likonen, Jari.

    In: Nuclear Fusion, Vol. 48, No. 3, 035008, 2008.

    Research output: Contribution to journalArticleScientificpeer-review

    TY - JOUR

    T1 - Deuterium removal during thermo-oxidation of Be-containing codeposits from JET divertor tiles

    AU - Tsui, C. K.

    AU - Haasz, A. A.

    AU - Davis, J. W.

    AU - Coad, J. P.

    AU - Likonen, Jari

    PY - 2008

    Y1 - 2008

    N2 - This study focuses on the removal of trapped D from thick codeposits on JET divertor tiles via thermo-oxidation. The tiles were removed from the JET Mark II Gas Box divertor after the 1998–2001 campaign. These codeposits have Be concentrations of up to ~60% Be/(Be + C) and their thicknesses range from 10 to 270 µm. Laser thermal desorption spectroscopy was used to determine the D removal rates and final remaining D concentrations following oxidation. Estimates of the carbon removed during oxidation were obtained from mass-loss measurements. The initial rate of D removal was found to be much higher for the thick codeposits of this study than for the previously studied codeposits with thicknesses in the range 1–5 µm (from TFTR, DIII-D and JET). This is despite the large Be concentrations. For oxidation performed at 623 K (350 °C) and 21 kPa (160 Torr) O2 pressure the initial D removal rates were found to increase linearly with increasing 'inherent' D content; about 50% of the inherent D was removed from all specimens in the first 15 min—independent of Be content and codeposit thickness. Following 8 h of oxidation, the fraction of D removed was >85% for all specimens, again, independent of Be content and thickness.

    AB - This study focuses on the removal of trapped D from thick codeposits on JET divertor tiles via thermo-oxidation. The tiles were removed from the JET Mark II Gas Box divertor after the 1998–2001 campaign. These codeposits have Be concentrations of up to ~60% Be/(Be + C) and their thicknesses range from 10 to 270 µm. Laser thermal desorption spectroscopy was used to determine the D removal rates and final remaining D concentrations following oxidation. Estimates of the carbon removed during oxidation were obtained from mass-loss measurements. The initial rate of D removal was found to be much higher for the thick codeposits of this study than for the previously studied codeposits with thicknesses in the range 1–5 µm (from TFTR, DIII-D and JET). This is despite the large Be concentrations. For oxidation performed at 623 K (350 °C) and 21 kPa (160 Torr) O2 pressure the initial D removal rates were found to increase linearly with increasing 'inherent' D content; about 50% of the inherent D was removed from all specimens in the first 15 min—independent of Be content and codeposit thickness. Following 8 h of oxidation, the fraction of D removed was >85% for all specimens, again, independent of Be content and thickness.

    KW - JET

    KW - divertor plasma

    KW - divertor tiles

    KW - fusion energy

    KW - fusion reactors

    KW - plasma

    KW - oxidation

    U2 - 10.1088/0029-5515/48/3/035008

    DO - 10.1088/0029-5515/48/3/035008

    M3 - Article

    VL - 48

    JO - Nuclear Fusion

    JF - Nuclear Fusion

    SN - 0029-5515

    IS - 3

    M1 - 035008

    ER -