为提高中能闪光照相实验能力, 给高能闪光照相的网栅设计制造提供新的思路, 结合前期2 mm厚网栅降散射的研究成果, 通过同时考虑网栅投射立体角的有阻挡和无阻挡部分, 分析了不同光子能量下网栅厚度对降散射效果的影响, 并设计制造了一种具有更高网栅比的网栅。采用100 kV光源对空心球体成像的实验验证其降散射效果, 结果表明, 网栅使图像对比度获得近1倍提升。采用实际的实验布局作为输入开展了蒙特卡罗模拟, 验证比较了新设计网栅降散射效果, 其降散射比高达1000∶1。

In this work an anti-scatter grid with higher grid ratio was designed and fabricated based on our previous 2mm grid studies. To clarify the influence of grid thickness and phonon energy on scattering reduction, the acceptance solid angle of a single grid hole was analyzed carefully, where both blocked and unblocked ray were considered. A radiographic experiment and a Monte Carlo simulation were conducted to verify the performance of the grid. Results indicate the contrast of image was nearly doubled when a grid was used. Scatter rejection of the grid was estimated to be at least 1000∶1, which is high enough to suppress most of the scatterings in various application scenes. Results in this work would be helpful in improving the image property of the medium-energy radiography and could be supplied as a valuable reference when designing and fabricating an anti-scatter grid for high-energy flash radiography.