中文摘要：

在部分相干光学理论的基础上,建立了一个整体相位衬度调制传递函数理论模型,模型中包含了光源焦点面积大小对X线相衬成像系统相位调制的影响,并通过数值模拟和数据计算,提出了X线相衬成像系统对光源焦点面积的选择原则,和焦点面积确定条件下的成像参数优化方法,结果表明,这种包含X线光源面积因素的相位衬度调制传递函数模型,更能反映整个系统的光学成像性能,更能有利于成像参数的优化设计。

英文摘要：

Based on the optical partially coherent theory,a new integral phase contrast modulation transfer function theoretical model is established in consideration of the X-ray source area parameter.Through the simulation and calculation,a comprehensive analysis of the spatial coherence of micro-focus X-ray phase contrast imaging system is displayed.A new source size selection method and parameter optimization method are put forward under the actual experimental condition.The results show that the model containing X-ray source area factor can reflect the entire performance of optical imaging system better,and avail to the imaging parameters optimization design.