KBA(改进的KB)型X射线显微镜为掠入射非共轴反射成像系统。前一组反射镜和后一组反射镜之间并不是严格垂直的, 给像质分析带来相当大的困难。通常的光学CAD软件难于适应这种光学系统。把共轴球面折射系统的向量公式调整后设计了掠入射非共轴KBA显微镜成像系统程序, 并用该程序分析了KBA系统的像差及综合误差。分析结果表明, KBA显微镜系统是大像差系统, 当物距公差为-0.4～+1 mm, 掠入射公差在-8″～0, 双反射镜夹角公差在-20″～0, 弥散斑的变化在允许的范围内。该程序对于分析和研制KBA显微镜系统具有重要意义。

KBA X-ray microscope is a grazing non-coaxial incident X-ray microscope. The front pair mirrors are not perpendicular to the back pair strictly, which brings much difficulty to the analysis of image quality. Thus general optical CAD program is not suitable to this kind of optical system. The co-axial spherical refrective vector formulations are adjusted to establish the program for the non-coaxial grazing incident microscope, with which the aberrations and the synthesis errors are analyzed. The analytical results show that KBA microscope is a large aberration system. For an object distance tolerance of -0.4～1 mm, the grazing angle tolerance is -8″～0″, the separation angle tolerance of two mirrors is -20″～0″, and the change of dispersion spot is in an allowed range. This program is meaningful for the analysis and fabrication of KBA microscope.