TY - JOUR
T1 - Effect of carbon impurity reduction on hydrogen isotope retention in QUEST high temperature wall
AU - Oya, Yasuhisa
AU - Sano, Atsuko
AU - Sato, Yurina
AU - Nakata, Moeko
AU - Zhou, Qilai
AU - Togari, Akihiro
AU - Yoshida, Naoaki
AU - Hanada, Kazuaki
N1 - Funding Information:
This work is performed with the support and under the auspices of the NIFS Collaboration Research program (NIFS16KUTR113) and the Collaborative Research Program of Research Institute for Applied Mechanics, Kyushu University.
Funding Information:
This work is performed with the support and under the auspices of the NIFS Collaboration Research program ( NIFS16KUTR113 ) and the Collaborative Research Program of Research Institute for Applied Mechanics , Kyushu University .
Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2019/9
Y1 - 2019/9
N2 - The W (tungsten) samples were placed at top, equator and bottom walls of QUEST (Q-shu University Experiment with Steady-State Spherical Tokamak) device and exposed 1238 shots of hydrogen plasma during 2016A/W (Autumn/Winter) campaign with normal wall temperature of 473 K (maximum temperature of 523 K). Thereafter, the surface morphology was evaluated by color measurement, TEM (Transmission Electron Microscope) and XPS (X-ray photoelectron spectroscopy). Thick deposition layers were formed on the samples placed at the equator and bottom walls. On the other hand, thin mixed material layer was deposited on the top wall, where large H (hydrogen) retention was observed, which would be caused by dynamic plasma wall interaction (erosion and deposition) with higher H flux. Low H retention was confirmed for bottom wall, where higher wall temperature without He discharge would contribute. The additional 1 keV D2 + was implanted into these samples and deuterium retention enhancement was estimated. It was clearly found that the irradiation damages would induce more deuterium trapping than the formation of C–D bond.
AB - The W (tungsten) samples were placed at top, equator and bottom walls of QUEST (Q-shu University Experiment with Steady-State Spherical Tokamak) device and exposed 1238 shots of hydrogen plasma during 2016A/W (Autumn/Winter) campaign with normal wall temperature of 473 K (maximum temperature of 523 K). Thereafter, the surface morphology was evaluated by color measurement, TEM (Transmission Electron Microscope) and XPS (X-ray photoelectron spectroscopy). Thick deposition layers were formed on the samples placed at the equator and bottom walls. On the other hand, thin mixed material layer was deposited on the top wall, where large H (hydrogen) retention was observed, which would be caused by dynamic plasma wall interaction (erosion and deposition) with higher H flux. Low H retention was confirmed for bottom wall, where higher wall temperature without He discharge would contribute. The additional 1 keV D2 + was implanted into these samples and deuterium retention enhancement was estimated. It was clearly found that the irradiation damages would induce more deuterium trapping than the formation of C–D bond.
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U2 - 10.1016/j.fusengdes.2019.02.110
DO - 10.1016/j.fusengdes.2019.02.110
M3 - Article
AN - SCOPUS:85063352477
SN - 0920-3796
VL - 146
SP - 1480
EP - 1484
JO - Fusion Engineering and Design
JF - Fusion Engineering and Design
ER -