为了降低闪光照相中散射的影响和提高法国试验客体(French test object,FTO)重建的精度,结合不同准直角下散射不同的特性,提出了不同准直角的双轴闪光照相布局,并进行了相应的数值模拟实验。研究结果表明:不同准直角双轴闪光照相中散射的相互干扰非常严重,且主要来于前保护器件,需使用铅板屏蔽。根据信息融合特性和降低散射影响的要求确定了FTO不同准直角双轴闪光照相的两个准直角分别为2.24°和1.15°。从该不同准直角的双轴闪光照相系统模拟得到的图像重建出了均方根误差小于5.8%的密度分布,结果远优于单轴照相23％的均方根误差。

In order to reduce the influence of scatter for radiography and increase the precision of the reconstructed object,the double-axis radiography system is proposed on the basis of using specific collimators. The double-axis radiography system has one collimator on each radiography axis,and the two collimators have different collimating angles. with such system the simulation radiography is carried out. The results show that the scatter from one axis to the other axis in radiography is large,and it is mainly from the front window. And it is reduced greatly by putting the lead block in the direction from front window to the detector on the other axis. The collimated angles for the FTO double-axis radiography is 2.24° and 1.15° according to the combining information and requirement of scatter reduction. From the image of the double-axis radiography simulation the object is reconstructed with the rms error of 5.8%. The result is much better than the single-axis X-ray radiography result.