Project/Area Number |
17560742
|
Research Category |
Grant-in-Aid for Scientific Research (C)
|
Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Nuclear engineering
|
Research Institution | The University of Tokyo |
Principal Investigator |
IWAI Takeo The University of Tokyo, Graduate School of Engineering, Assistant Professor (30272529)
|
Co-Investigator(Kenkyū-buntansha) |
ABE Hiroaki The University of Tokyo, Graduate School of Engineering, Associate Professor (40343925)
TSUCHIDA Hidetsugu Kyoto University, Graduate School of Engineering, Assistant Professor (50304150)
濱口 大 独立行政法人日本原子力研究開発機構, 量子ビーム応用研究部門, 研究員 (60396926)
|
Project Period (FY) |
2005 – 2007
|
Project Status |
Completed (Fiscal Year 2007)
|
Budget Amount *help |
¥3,610,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥210,000)
Fiscal Year 2007: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2006: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2005: ¥2,100,000 (Direct Cost: ¥2,100,000)
|
Keywords | void swelling / nanovoid / metal / positron annihilation spectroscopy / nickel / 陽電子ビーム / イオン照射 |
Research Abstract |
Vacancy defects produced during ion irradiation were studied by using an irradiation system combined with a slow-positron apparatus and a high-energy ion accelerator. For two fcc metals of Ni and Al, in situ positron annihilation Doppler broadening measurements were performed during irradiation and non-irradiation. We found that an increase in the S parameter occurs during irradiation for Ni, but not for Al. The result for Ni strongly suggests that vacancy concentration during irradiation is high compared to that survived after irradiation, i. e., it includes transient or non-survivable vacancies. The formation of such a transient vacancy will be closely related to processes of defect accumulation or defect clustering. The present in situ observation technique is demonstrated to serve as a powerful tool for the investigation of vacancies produced in materials under an ion irradiation environment. The Doppler broadening line-shape of positron annihilation radiation is known to provide comparative information but less information about defect characteristics such as the density and the open volume size. In contrast, positron lifetime measurements allow obtaining quantitative information. We plan to do further experiments on in situ positron lifetime measurement during ion irradiation of materials in order to obtain more accurate insights into the dynamics of irradiation effects, in particular a quantitative understanding of vacancy characteristics induced transiently during irradiation.
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