Effects of modified surfaces produced at plasma-facing surface on hydrogen release behavior in the LHD
| Autor: | N. Ashikawa, Yasuhisa Oya, Hiroshi Kasahara, Gen Motojima, D. Nagata, Mitsutaka Miyamoto, Yuji Yamauchi, Nobuaki Yoshida, M. Yajima, Noriyasu Ohno, Yuji Nobuta, M. Tokitani, Suguru Masuzaki |
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| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Nuclear and High Energy Physics
Materials science Hydrogen retention Desorption Redeposition Long-term sample LHD Hydrogen Materials Science (miscellaneous) Analytical chemistry chemistry.chemical_element Substrate (electronics) 01 natural sciences 010305 fluids & plasmas 0103 physical sciences Boron 010302 applied physics lcsh:TK9001-9401 Carbon film Nuclear Energy and Engineering chemistry lcsh:Nuclear engineering. Atomic power Carbon Deposition (chemistry) Layer (electronics) |
| Zdroj: | Nuclear Materials and Energy, Vol 12, Iss, Pp 483-487 (2017) |
| ISSN: | 2352-1791 |
| Popis: | In the present study, an additional deuterium (D) ion irradiation was performed against long-term samples mounted on the helical coil can and in the outer private region in the LHD during the 17th experimental campaign. Based on the release behavior of the D and hydrogen (H) retained during the experimental campaign, the difference of release behavior at the top surface and in bulk of modified surfaces is discussed. Almost all samples on the helical coil can were erosion-dominant and some samples were covered with boron or carbon, while a very thick carbon films were formed in the outer private region. In the erosion-dominant area, the D desorbed at much lower temperatures compared to that of H retained during the LHD plasma operation. For the samples covered with boron, the D tended to desorb at lower temperatures compared to H. For the carbon deposition samples, the D desorbed at much higher temperatures compared to no deposition and boron-covered samples, which was very similar to that of H. The D retention capabilities at the top surface of carbon and boron films were 2–3 times higher than no deposition area. The results indicate that the retention and release behavior at the top surface of the modified layer can be different from that of bulk substrate material. Keywords: Hydrogen retention, Desorption, Redeposition, Long-term sample, LHD |
| Databáze: | OpenAIRE |
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