Development of X-ray Imaging Technique for Liquid Screening at Airport

X-ray imaging technology is a viable option to recognize flammable liquids for the purposes of aviation security. In this study, an X-ray imaging technology was developed whereby, the image viewing system was built with the use of a digital camera coupled with a gadolinium oxysulfide (GOS) fluorescent screen. The camera was equipped with a software for remote control setting of the camera via a USB cable which allows the images to be captured. The image was analysed to determine the average grey level using a software designed by Microsoft Visual Basic 6.0. The data was obtained for various densities of liquid between 0.7 to 1.4 g/cm3 contained in a thin plastic bottle with diameter of 4.5 cm, 6.0 cm and 7.5 cm for X-ray energies ranging from 70 to 200 kVp. In order to verify the reliability of the constructed calibration data, the system was tested with a few types of unknown liquids. The developed system could be conveniently employed for security screening in order to discriminate between a threat and an innocuous liquid.

X射线成像技术（X-ray Imaging Technology）是航空安保场景下识别易燃液体的可行技术路径。本研究开发了一套X射线成像方案，其图像采集系统由数码相机与氧硫化钆（Gadolinium Oxysulfide, GOS）荧光屏耦合搭建而成。该数码相机配备了支持通过USB线缆实现远程参数设置与图像采集的配套软件。采用基于微软Visual Basic 6.0开发的图像处理软件，对采集得到的图像进行分析以计算平均灰度值。本实验采集了密度介于0.7~1.4 g/cm³的各类液态样本的数据，样本盛装于直径分别为4.5 cm、6.0 cm与7.5 cm的薄塑料瓶中，测试所用X射线能量范围为70~200 kVp。为验证所构建校准数据集的可靠性，研究团队使用多种未知液态样本对该系统开展了测试验证。所开发的这套系统可便捷应用于安检筛查场景，以区分危险液态威胁物与无害液态物品。