中文摘要：

本文采用蒙特卡罗方法对高能中子下针孔成像系统的点扩展函数进行了模拟研究。研究中采用高斯函数拟合的数学方法分析比较了该系统在两种不同探测器材料下的点扩展函数，并在此基础上得出相应的调制传递函数。研究结果表明，在较高能量的中子入射下，采用塑料闪烁光纤代替传统的无机闪烁体作为成像探测器材料将能够提高针孔成像系统的点扩展函数，进而得出若采用闪烁光纤阵列作为探测器将能够提高系统的调制传递函数的结论。

英文摘要：

Point spread function （PSF） of a pinhole imaging system with plastic scintillation fiber and NaI array detectors to detect 6 MeV neutrons was simulated using Monte-Carlo method. By fitting the simulation data with Gauss function, PSFs and their corresponding modulate transfer functions （MTF） of the pinhole imaging system were obtained. The results show that the system of plastic-scintillating fiber array detector has much better spatial resolution and imaging quality than the NaI system.