Development of ultra precision aspherical form measurement equipment for synchrotron radiation mirror. Measurement of hard X-ray focusing mirror and comparison of interferometer

A new ultra-precision profiler was developed to measure X-ray and EUV optics such as asymmetric and aspheric profiles. In the present study, the normal vectors at each points on the surface are determined by the reflected light beam goes back exactly on the same path as the incident beam. The surface gradients at each point are calculated from the normal vector and the surface profile is obtained by integrating the gradient. An elliptical profile mirror for nanometer hard X-ray focusing were measured using the present instrument and compared to the measured profile using Zygo phase-measuring interferometer. The absolute measurement accuracy of approximately 5 nm (P-V) was achieved. (author)