关键词: X射线, 安全检查, 物质识别, 双能量, 原子序数

Abstract: Compares the single and dual-energy X-ray transmission technology and analyzes the difference between them. It is found that how the mass attenuation coefficients of two materials change are different even their atomic numbers are the same when the incident energies are different. It implies that when irradiated by dual energy X-ray, i.e., high and low energies are both absorbed, the absorptance of the two materials of the same atomic number are different. Thus the objects which are composed of two different materials/thicknesses or in overlapping image, can be differentiated from each other by way of calculating and comparing the different absorption coefficients as irradiated by low and high energy X-rays. In this way the aluminium plate and polymethyl methacrylate plate are taken as specimens to be tested, and the results show that the boundary curves to classify different materials are reliable.