双能X射线检查系统的Monte Carlo模拟  

Monte Carlo simulations of dual energy X-ray inspection systems

作　　者：张国伟[1] 张丽[1] 陈志强[1] 

机构地区：[1]清华大学工程物理系,北京100084

出　　处：《清华大学学报（自然科学版）》2006年第6期813-816,共4页Journal of Tsinghua University(Science and Technology)

基　　金：国家自然科学基金资助项目(10135040)

摘　　要：为了提高双能X射线安全检查系统的材料分类能力,采用M on te C arlo方法对系统的成像过程进行了模拟。利用M CNP 4C程序模拟电子打击钨靶产生韧致辐射、射线与物质的相互作用,得到了材料分类曲线。与数值方法以及实验方法相比,该方法的材料分类不受系统噪声影响,可以分辨原子序数相差为1的两种材料,并且只需要几m in计算时间。进行了铝阶梯的实验,对一系列典型材料和专用测试工具箱进行了测试。结果表明,M on te C arlo模拟方法可以提高安全检查系统的材料分辨能力。The imaging process for dual energy X-ray security inspection systems was simulated using the Monte Carlo method to improve material classification. The bremsstrahlung generated by the electron beam impinging the tungsten target and the interactions between the X-rays and the materials were simulated using the MCNP4C code. The results accurately show the material edges. Compared to previous experimental results and numerical algorithms, the classification curves from the Monte Carlo simulations are not affected by system noise and can achieve materials discrimination when the atomic number difference is one, with a computational time of several minutes. Tests on a series of representative materials and special testing toolboxes show that the Monte Carlo method improves the material classification of practical security inspection systems.

关 键 词：辐射成像 双能量 材料分辨 MONTE CARLO方法 

分 类 号：TL81[核科学技术—核技术及应用]