快中子成像空间分辨率部分影响因素的模拟研究

摘要

In this article,the three parameter:incident neutron energy,target to source distance and detector to target distance,which influence greatly on spatial resolution of neutron imaging system,are simulated and ana-lyzed through Monte-Carlo method.The modulation transfer function varied with the three parameters is ana-lyzed by Geant4 tools and some simulation results are important and useful for the parameter selection in prac-tice.At the same time,the feasibility of applying lead isolation layer to crosstalk suppression in neutron imaging is also discussed through the simulation.As the result show, the lead layer played a positive role in improving spatial resolution with appropriate thickness,which provides valuable theoretical guidance for the selection of pa-rameters in practical work.%采用蒙特卡罗方法对中子成像系统空间分辨率产生重要影响的三个参数（入射中子能量、样品靶与源的距离和探测器与样品靶的距离）进行了模拟研究。利用Geant4模拟计算得到了快中子照射下，调制传递函数随上述参数的变化曲线，这三个参数的选择对成像性能的优化有着很大的指导意义。同时，通过模拟还分析了利用铅隔离层抑制串扰在中子成像中的可行性。研究结果表明，选择合适的铅层厚度在一定程度上提高图像质量，这些结果可为实际工作中的参数选择提供参考。