KB镜成像模拟以及与菲涅耳波带板成像的比较

Kirkpatrick-Baez Mirror Imaging Simulation and Comparison with Fresnel Zone Plate Imaging

采用坐标变换方法自编光线追迹程序模拟了Kirkpatrick-Baez镜在X射线波段的掠入射成像,获得了视场、分辨率等结果.比较了给定参量条件下Kirkpatrick-Baez镜与菲涅耳波带板两种高分辨X射线成像的特性,给出两者各自适用范围.Kirkpatrick-Baez镜成像有比较高的系统效率,在视场中心的空间分辨能力可达0.71μm,但偏离视场中心±200μm,空间分辨能力显著下降至6μm,适用于较小视场的成像.菲涅耳波带板成像不仅在视场中心可以实现0.39μm的空间分辨能力,偏离视场中心达±13 mm,空间分辨能力也几乎不变,可实现大视场高分辨成像.

The imaging characteristics of a Kirkpatrick-Baez（KB） mirror were studied using a home-developed code.The numerical recipe of the code was based on coordinate transformation of ray tracing.The spatial resolution and the field of view were obtained.For given parameters,the properties of the KB mirror imaging were compared to that of a Fresnel zone plate（FZP）,and the application range of the two imaging techniques was given.The KB mirror has a relatively high efficiency.Its spatial resolution is 0.71 μm in the centre of the field of view,but decreases to 6μm as the object position deviates from the field-of-view center by±200μm,thus it is suitable for small field-of-view imaging.The FZP can realize a higher spatial resolution up to 0.39μm and the resolution almost unchanges within±13 mm field of view,which can be applied to large field-of-view,high-resolution X-ray imaging.