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Hydrogen accumulation and surface bubbling of liquidized Sn-Bi-Li-Er alloy under hydrogen plasma exposure

ORAL

Abstract

Behavior of liquidized Sn-Bi-Li-Er (SBLE) alloy under hydrogen plasma exposure is investigated for its application to nuclear fusion devices. SBLE is liquidized in a vacuum chamber using infrared heater and is exposed to inductively coupled hydrogen plasma. Surface morphology of the SBLE is observed by a high-speed camera and time variation of H2 partial pressure is monitored by a differentially-pumped quadruple mass analyzer (QMA). During hydrogen plasma exposure, bubbling phenomenon on the liquidized SBLE surface is observed. With varying ion flux to the SBLE sample, increase in bubble rupture per unit time is seen. H2 accumulation inside the bubble is confirmed by partial pressure measurement using the QMA. Droplets produced by ruptured SBLE bubble is investigated by X-ray photoelectron spectroscopy and Li atomic composition of >99% is observed. From the result, Li segregation followed by lithium hydride formation on the surface is suggested as the origin of the bubble formation.

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Presenters

  • Kota Tamura

    Nagoya University

Authors

  • Kota Tamura

    Nagoya University

  • Haruka Suzuki

    Dept. of Electronics, Nagoya Univ., cLPS, Nagoya Univ., Department of Electronics, Nagoya University; Center for Low-temperature Plasma Sciences, Nagoya University, Nagoya University, Center for Low-temperature Plasma Sciences, Nagoya university

  • Junichi Miyazawa

    National institute for fusion science

  • Suguru Masuzaki

    National Institute for Fusion Science, NIFS, National institute for fusion science

  • Masayuki Tokitani

    National institute for fusion science

  • Hirotaka Toyoda

    Dept. of Electronics, Nagoya Univ., cLPS, Nagoya Univ., NIFS, Department of Electronics, Nagoya University; Center for Low-temperature Plasma Science, Nagoya University; National Institute of Fusion Science, Nagoya University, Center for Low-temperature Plasma Sciences, National Institute of Fusion Science, Nagoya university