The Concentration Determination for High Atomic Number Elements by <gamma>-Ray Excited DX-Ray Spectrometry

Research Project

Project/Area Number	61460150
Research Category	Grant-in-Aid for General Scientific Research (B)
Allocation Type	Single-year Grants
Research Field	計測・制御工学
Research Institution	Toyohashi University of Technology
Principal Investigator	ENOMOTO Shigemasa Professor, Faculty of Eng., Toyohashi University of Technology, 工学部, 教授 (00124727)
Co-Investigator(Kenkyū-buntansha)	HIGASHIYAMA Yoshio Lecturer, Faculty of Eng., Yamagata University, 工学部, 講師 (50144209)
Project Period (FY)	1986 – 1987
Project Status	Completed (Fiscal Year 1987)
Budget Amount *help	¥3,700,000 (Direct Cost: ¥3,700,000) Fiscal Year 1987: ¥900,000 (Direct Cost: ¥900,000) Fiscal Year 1986: ¥2,800,000 (Direct Cost: ¥2,800,000)
Keywords	high atomic number element / concentration determination / Cs-137 <gamma>-ray source / fluorescent X-ray Compton scttering / high purity germanium semiconductor detector / 高純度ゲルマニウム半導体検出器 / 非分散分光測定 / γ線源 / 蛍光X線分析 / 高Z元素 / Ge半導体検出器 / KX線 / Compton / 散乱
Research Abstract	In order to determine the concentration of high Z elements, KX-ray fluorescence technique by using a Cs-137 <gamma>-ray source (half-life 30.17 years, 662 KeV <gamma>-ray) with non-dispersive spectrometry using a high pure germanium semiconguctor detector is investigated. It is possible with this technique to analyse the specimens enclosed in containers or pipe lines. The Cs-137 <gamma>-ray has enough energy to excite the KX-rays of high Z elements, however considerable amount of Compton scattered <gamma>-rays in specimens is produced, and large ratio of the KX-rays to the scattered radiation from specimens is required to have sufficient accuracy. In this method, the scattered radiation should be reduced to improve the ratio by setting up the geometry between the source, specimen and X-ray detector. The variation of specimen conditions such as density, particle size, matrix composition affect much on the characteristic calibration curves related to the concentration vs. KX-ray/Compton count ratio. The 300 second measurement allows the relative precision of less than 3% for powder, aqueous solution, and all alloy specimens containing more than a few wt% W, Pb or U.