2005 Fiscal Year Final Research Report Summary
Dynamic mixing effects on hydrogen diffusion and retention in high Z materials
| Project/Area Number |
15560715
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Nuclear fusion studies
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| Research Institution | Osaka University |
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Principal Investigator |
UEDA Yoshio Osaka University, Graduate School of Engineering, Associate Professor, 大学院・工学研究科, 助教授 (30193816)
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| Co-Investigator(Kenkyū-buntansha) |
NISHIKAWA Masahiro Osaka University, Graduate School of Engineering, Professor, 大学院・工学研究科, 教授 (50029287)
OHTSUKA Yusuke Osaka University, Graduate School of Engineering, research associate, 大学院・工学研究科, 助手 (70294048)
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| Project Period (FY) |
2003 – 2005
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| Keywords | tungsten / blistering / plasma facing materials / MeV ion beam / irradiation damage / hydrogen and carbon mixed ion beam |
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| Research Abstract |
Hydrogen and carbon mixed ion beam was irradiated to tungsten to study the effects of dynamic mixing of tungsten and carbon layer on blistering and hydrogen diffusion characteristics. It was found that only 0.3% of carbon or more strongly enhanced blistering. Tungsten and carbon mixed layer formed on the tungsten surface acted as hydrogen emission barrier and enhanced hydrogen diffusion toward bulk, leading to blister formation. In addition to carbon, ash of fusion reaction, helium, was added to the ion beam to study the effect of helium on hydrogen behavior in tungsten. Only 0.1% of helium addition suppressed blister formation. In fusion reactors, fusion neutrons are irradiated to in vessel materials. Fast neutrons produce damages in these materials. Therefore it is important to study the effects of this irradiation damage on hydrogen behavior in tungsten. To study this subject, 700 keV hydrogen negative ion beam was irradiated to tungsten before mixed ion beam irradiation. It was found that pre irradiation of high energy hydrogen ion beam suppressed the production of small size (<10μm) blisters. In future, the effects of repetitive heat load will also investigated.
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