关键词: 双能量, X射线探测, 安全检查, 有效原子序数, 物质识别, 能量分离

Abstract: To classify different materials from the images by dual-energy X-ray transmission, the current method to calculate the Eigenvalue R relating to effective atomic number is combining the high-energy transmission signal with low-energy one. But, the thickness of object affects greatly the R value. So, a ratio of the two transmission signals is proposed to eliminate the effect of object thickness instead, i.e., an optimal numerical computation by which the optimized transmission signals can be obtained through compound Simpson's rule to estimate area absorption coefficient. Analyzing the test data and error probability, the method proposed is proved available to minimize the thickness effect with less mistake, thus improving the veracity in classifying materials.