基于能量色散X射线散射方法的液体物质探测与识别研究

Application of Detection and Identification of Liquid Materials Based on Energy Dispersive X-ray Scattering

固定散射角θ,采用连续波长的X射线对3类纯液体物质(伯醇、苯同系物与氯代甲烷)进行了能量色散X射线散射实验,得到了上述纯液体物质的能量色散X射线散射图谱。结果表明,每种液体物质的能量色散X射线散射图谱的峰形与峰位置彼此不同。伯醇随着碳链长度的增加,散射峰宽变窄,主峰位置向小的散射参数动量转移(q)值方向移动。苯同系物的散射曲线的峰形彼此不同,且主峰峰位的q值从苯、甲苯、邻二甲苯依次降低。氯代甲烷散射曲线的峰形随着取代氯原子数目不同而不同。液体物质的密度影响散射光谱的峰位置。液体物质散射曲线的差异与液体物质的组成、化学结构以及密度紧密相关。液体物质能量色散X射线散射图谱所揭示的峰形与峰位等特征信息,预示着能量色散X射线散射方法有可能作为非破坏性、非接触式检测与识别隐藏液体物质的有效手段。

Energy dispersive X-ray scattering（EDXRS） experiments of three types of pure liquid（primary alcohols,benzene homologues and chloromethanes） have been investigated using a broad energy band polychromatic x-ray beam with a fixed scattering angle θ,and X-ray scattering spectra of these liquid materials have been described.It is shown that the shapes and maximal peak locations of the scattering profiles for all samples are different under the same probe conditions.With improving the length of carbon chain,the width of peak is diminishingly narrowing and the maximal peak position shifts to lower q values.The scattering shapes of benzene homologues are characteristic distinctions,and the maximal peak position shifts to lower q values from benzene,methylbenzene to o-xylene.Each substituted chloromethanes clearly produces its own distinct shape of curves with increasing the number of substituted chlorine from dichloromethane,trichloromethane to tetrachloromethane.The peak locations of the scattering spectra are affected by the density of liquid materials.The difference of scattering curves is ascribed to the composition,molecular structure and density of liquid and hence could be used to characterize the liquid.The shapes and peak locations of the scattering curves suggest that EDXRS is a promising non-invasive and non-contact method to detect and identify concealed liquid materials.