X射线横向移动成像法识别土壤中物体的蒙特卡罗模拟

Monte Carlo Simulation of Materials Under the Soil Diagnosed by X-ray Lateral Migration Radiography Method

X射线横向移动成像是一种新的散射成像方法,直接利用大面积探测器分开探测单次和多次散射光子强度来识别被覆盖物体的组成类型、尺寸和浅表面缺陷等,法已被用于地雷探测。利用蒙特卡罗模拟软件MCNP5分别模拟了覆盖于土壤中的不同横向面积的铁、TNT以及含空气缺陷的TNT中X光子的散射过程。根据模拟结果分析了两类探测器上散射光子的强度与被测物等效原子序数和尺寸之间的关系,这些关系构成了利用X射线横向移动散射法识别物体的依据,初步给出了利用该方法识别土壤中物体需要满足的条件及其识别能力。

X-ray lateral migration radiography（LMR） is a new form of backscatter imaging that utilizes both multiple-scatter and single-scatter photons detected by large area detectors,which contain the information such as the shape and subsurface flaws of objects.The LMR method has been used to detect the landmine.MC-NP5 has been used to simulate X-ray photons scattering process in varying dimension of Fe,TNT and TNT with air flaws from a LMR simulation setting.The relations between the scattering photons intensity and equivalent the atomic number as well as the dimension of objects were analyzed,and these relations are the foundation of the LMR methods.The condition and ability of materials under soil diagnosed by the LRM method are obtained.