闪光照相散射模拟结果实验检验

Experimental verification of scattering simulation in flash radiography

在介绍照射量计算方法的基础上,依据散射的主要来源,给出了一种从实验上检验蒙特卡罗散射模拟精度的方法。该方法的核心是:构造一对有关联的照相布局——二者具有相同的直穿强度和不同的散射强度,两种照相布局的成像图像之差对应于它们的散射之差,其中前者可以用实验测量得到而后者可以用蒙特卡罗模拟得到,我们对三组客体模型进行了闪光照相实验和蒙特卡罗数值模拟,发现每一种客体模型下的成像图像之差及散射之差的分布形状都非常相似,并且具有几乎一致的比例系数约为4.95。

The accurate Monte Carlo（MC） simulation of scattering X-ray intensity is crucial in high energy flash radiography.On the basis of introducing the calculation method of exposure,a way for experimentally testifying the MC scattering simulation is proposed according to the main seattering source.The key is to construct a pair of correlated experiments which have the same direct component and different seattering component,so their image gray difference is related to their scattering difference ΔX,where ΔG can be measured experimentally and ΔX can be calculated by MC simulation.ΔG and are measured and calculated in three different radiography models.It is found that in all the three models the ΔG have similar distribution with ΔX,and the ratio ΔG/ΔX is nearly same as 4.95.This confirms the validation of the method and also confirms the correctness of the MC scattering simulation results.