高能闪光照相密度测量的LEPM方法

研究了利用高能闪光照相方法实现密度分布测量的技术.根据闪光照相投影成像原理,将成像过程中的非线性成像因素看成一个综合性的非线性算子,利用先验测量的方法该非线性算子的响应曲线,利用该曲线校正成像图像得到待测客体的光程分布图像.采用以最小误差为重建准则的代数重建法,从光程分布图像中重建出照相客体的线吸收系数分布.最后利用相对等效质量吸收系数以及客体总质量不变的约束条件,获得照相客体的空间密度分布.在高能闪光照相实验平台上进行了静态客体的密度测量实验,测量的均方根误差约为10％.

Density Reconstruction by Flash Radiography Using LEPM

Quantitative density reconstruction of an object in detonation process using high-energy flash radiography is described.In order to obtain the path length of the object,the radiographic image of the object is corrected by an integrated nonlinear function that represents the nonlinear imaging process of the high-energy flash radiographic system.The function is measured from the image that is obtained from a pre-knowing sample,and the sample is structural similitude with the object.The path length is reconstructed by algebraic reconstruction technique with the rule of least error.Then the density distribution of the object is obtained form the result of reconstruction when the mass absorption coefficient is deducted.A series of density reconstructions of a static radiographic test object is obtained by the radiographic system,and the results show that the errors of the density reconstruction are approximated to 10%.