Development of radiation damage dating by AFM

2014 Fiscal Year Final Research Report

• Project/Area Number: 24654173
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Petrology/Mineralogy/Science of ore deposit
• Research Institution: Kanazawa University
• Principal Investigator: HASEBE Noriko 金沢大学, 環日本海域環境研究センター, 准教授 (60272944)
• Co-Investigator(Renkei-kenkyūsha): TAKESHI Fukuma 金沢大学, 理工学域電子情報学系, 教授 (90452094)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 放射線損傷 / フィッショントラック / ジルコン

Outline of Final Research Achievements

The number of fission tracks (FT) is counted under an optical microscope after etching. However, as FT density per unit area rises, it becomes difficult to count the number of tracks because tracks overlap one another and are unable to be readily distinguished. The atomic force microscope (AFM) has a potential to observe fission tracks with high density after a short time etching.　This research developed sample preparation techniques (e.g., polishing and etching) for AFM observation, established equipment settings for image capturing, and applied to date practical samples. The results were satisfactory, though the sample as old as 1 Ga is the oldest limit to be dated because the weak etching prevents extraction of FT from other structures. High resolution of AFM enables observation of possible alpha recoil tracks in zircon.

Free Research Field

地球年代学