Development of the Technology of PIXE Analysis

• Published in: Advances in X-Ray Chemical Analysis, Japan Vol. 50; pp. 49 - 66
• Main Author: ISHII, Keizo
• Format: Journal Article
• Language: Japanese
• Published: The Discussion Group of X-Ray Analysis, The Japan Society for Analytical Chemistry 31.03.2019; 公益社団法人 日本分析化学会 X線分析研究懇談会
• Subjects: Atomic Bremsstrahlung; Fukushima daiichi nuclear power plants accidents; Inner-shell ionization; Micro beam; Micro-CT; Micro-PIXE; Particle induced X-ray emission; PIXE; マイクロPIXE; マイクロビーム; ミクロンCT; 内殻電離; 原子制動輻射; 福島第一原子力発電所事故; 粒子線励起X線放出
• ISSN: 0911-7806; 2758-3651
• DOI: 10.57415/xshinpo.50.0_49

When charged particles collide with atoms, atomic inner shell electrons are ionized and then characteristic X-rays are emitted. This phenomenon is called Particle Induced X-ray Emission: PIXE. Since the production cross-sections of characteristic X-rays in PIXE is very large, PIXE can be applied to trace element analysis and uranium from sodium can be simultaneously analyzed with the sensitivity of ppb. Two dimensional distributions for each element can be obtained by scanning ion beams on the surface of sample. The use of micro beams enables to investigate elements inside a cell: Micro-PIXE analysis. A micron size point source of monochromatic X-ray is made by irradiating a metal target with micro-beams and can be used to an X-ray CT with the spatial resolution of 1 μm: Micron X-ray CT. Three dimensional distributions of elements in the inside of sample with 100 μm size can be non-destructively obtained using absorption edges for each element. The PIXE analysis is now applied to medicine, biology, fisheries science, agriculture, geology, petrology, environmental problems, archeology, resource search, material science, chemistry, astrophysics, earth science, criminal investigation, food inspection etc. To investigate the radioactive cesium contamination of foods and soil by the Fukushima Daiichi Nuclear power plants accidents, Micro-PIXE and Micron X-ray CT were useful especially in rice grain and in clay, respectively.