研制了一套结构简单、易于操作的条纹反射测量系统,用以测试Angel型龙虾眼X射线镜片的面型。通过电荷耦合器件(CCD)相机拍摄40 mm×40 mm口径的龙虾眼镜片的条纹反射图像,计算得到了龙虾眼镜片面型的斜率误差分布,并通过积分得到了龙虾眼镜片的面型误差均方根及峰谷值,分别为0.81 μm和6.34 μm。该结果与Zygo干涉仪得到的面型分布规律大体一致。基于条纹反射方法重复测量面型得到的均方根和峰谷值的标准差分别为0.017 μm和0.11 μm,验证了条纹反射方法测量龙虾眼镜片面型的可行性。利用蒙特卡罗方法对待测龙虾眼镜片的面型误差进行X射线聚焦成像模拟,得到面型误差引起的弥散十字焦斑的半峰全宽为0.23 mm,对应的角分辨率为2.11'。该光学测量系统的建立为龙虾眼镜片的球面热成形提供了参考依据。

A fringe reflection measurement system with simple structure is developed to measure the surface of an angel lobster eye X-ray lens, and it is easy to operate. First, a fringe reflection image of the lobster eye lens whose size is 40 mm×40 mm is taken by a charged coupled device camera, and the slope error distribution of the lens surface is calculated. The root mean square (RMS) and peak-to-valley (PV) values of the lobster lens obtained by the fringe reflection measurement system are 0.81 μm and 6.34 μm, respectively. The measurement results of the proposed system are consistent with those of the Zygo interferometer. The standard deviations of the RMS and PV values obtained by repeated surface measurements are 0.017 μm and 0.11 μm, respectively. The feasibility of the fringe reflection measurement system for measuring the surface of an angel lobster eye X-ray lens is verified. Then, the X-ray focus imaging simulation is performed for the measurement of the surface error of the lobster eye lens based on the Monte Carlo method. The full width at half maximum of the diffuse focal spot caused by the surface error is approximately 0.23 mm, and the corresponding angular resolution is 2.11'. This optical measurement system provides a reference for the spherical forming of the lobster eye lens.