非共轴掠入射KB与KBA X射线显微镜的成像特性分析

由于X射线在介质中被强烈地吸收，加之介质的折射率在X射线波段略小于1，这些因素给X射线成像增加了很多难度，常规的成像方法难以适应X射线波段，目前多采用掠入射反射成像和编码孔径成像方法。详细分析掠入射情况下单镜及双反射镜的成像特性，对组成KBA显微镜的反射镜在掠入射条件下的焦距、视场倾斜、光阑位置等进行研究。研究结果表明：对于双反射镜结构，掠入射角为双反射镜夹角1/2时视场倾斜最少，光阑放在第2个镜子上成像质量优于放在第1个镜子上。最后分析KBA显微镜结构安排的合理性，从而为KBA显微镜设计和加工提供理论依据。

Imaging characteristics for non-coaxial grazing-incidence

Since the refractive index of media in the X-ray region is lower than 1 and X-ray is strongly absorbed by media,it is very difficult to image objects in the X-ray region.Conventional imaging methods are not suitable to x-ray wave band. Generally,the methods of the grazing-incidence reflective imaging and coding aperture imaging are often used. Imaging quality of a single mirror and two mirrors in the case of grazing incidence is discussed. The focal length,field obliquity and diaphragm position of KBA microscope are analyzed. The results show that the field obliquity is the minimum when the grazing-incident angle is half of the angle between the two mirrors,and the imaging quality is better when the diaphragm is placed on the second mirror instead of the first one. The reasonable structure arrangement of KBA microscope is analyzed. The theoretical basis is provided for the design and manufacture of KAB microscope.