Development of Post-ionization method for next-generatino in-situ U-Pb dating mass spectrometer

2015 Fiscal Year Final Research Report

• Project/Area Number: 26610183
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Geochemistry/Cosmochemistry
• Research Institution: Osaka University
• Principal Investigator: Terada Kentaro 大阪大学, 理学(系)研究科(研究院), 教授 (20263668)
• Co-Investigator(Kenkyū-buntansha): 石原 盛男 大阪大学, 理学(系)研究科(研究院), 准教授 (30294151) ; 中村 亮介 大阪大学, 産学連携本部, 講師 (70379147) ; 豊田 岐聡 大阪大学, 理学(系)研究科(研究院), 教授 (80283828) ; 青木 順 大阪大学, 理学(系)研究科(研究院), 助教 (90452424)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: 局所分析 / 太陽系年代学 / 年代測定 / 同位体

Outline of Final Research Achievements

Secondary Ion Mass Spectrometers (SIMSs), which have high spacial resolution (1~10 micron), have been used for isotopic measurement of individual minerals and/or presolar grains. The weakest point of this analytical method is that secondary ion yield is very low (less than 1 %). As a result, a large amount of sputtered atoms and molecules that are neutral are wasted.
To overcome this weakness of SIMSs, we adopted the post-ionization method using high-intensity laser, and have developed a multi-turned TOF-SIMS with a femto-second laser for post-ionization. By optimizing the timing of irradiation/acceralation and/or position of laser, we currently attain the multiplication factor of c.a. 10000. As a result, we succeeded in detection of U and Pb ions from natural zircon of which U concentration is about 100 ppm.

Free Research Field

宇宙地球化学