Interaction between hydrogen and defects in alloys studied by positrons produced by pair creation from LCS-gamma rays

2016 Fiscal Year Final Research Report

• Project/Area Number: 26289365
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Nuclear engineering
• Research Institution: Osaka Prefecture University
• Principal Investigator: Hori Fuminobu 大阪府立大学, 工学(系)研究科(研究院), 准教授 (20275291)
• Co-Investigator(Kenkyū-buntansha): 寺澤 倫孝 兵庫県立大学, 付置研究所, 研究員 (20197792) ; 井上 博之 大阪府立大学, 工学(系)研究科(研究院), 准教授 (40203252) ; 岩瀬 彰宏 大阪府立大学, 工学(系)研究科(研究院), 教授 (60343919) ; 宮本 修治 兵庫県立大学, 付置研究所, 教授 (90135757)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 格子欠陥 / 金属 / 陽電子消滅 / 水素

Outline of Final Research Achievements

A new positron production and measurement apparatus has been developed at a synchrotron radiation (SR) facility. Mega eV ordered positrons were created via pair creation in a Pb target by implantation of 16.7 MeV gamma-photons generated via inverse Compton scattering of visible laser beam from a 1 GeV electron beam circulating in the storage ring at the NewSUBARU-SR facility. Positrons, with an energy of 8 MeV, are directly implanted into a bulk sample to detect defects. By using this system, we have performed positron annihilation Doppler broadening measurement for bulk iron samples after corrosion test. In this experiment, we found that vacancy type defects were induced by hydrogen charging at a 4 mm depth from the surface by non-destruction measurement. Also, positron measurement results suggest that the different possibility of hydrogen trapping may occur at different type of vacancies in compound alloys.

Free Research Field

金属材料