Development of a high-performance gantry system for a new generation of optical slope measuring profilers

Abstract

A new high-performance metrology gantry system has been developed within the scope of collaborative efforts of optics groups at the US Department of Energy synchrotron radiation facilities as well as the BESSY-II synchrotron at the Helmholtz Zentrum Berlin (Germany) and the participation of industrial vendors of x-ray optics and metrology instrumentation directed to create a new generation of optical slope measuring systems (OSMS) [1]. The slope measurement accuracy of the OSMS is expected to be <50nrad, which is strongly required for the current and future metrology of x-ray optics for the next generation of light sources.The fabricated system was installed and commissioned (December 2012) at the Advanced Photon Source (APS) at Argonne National Laboratory to replace the aging APS Long Trace Profiler (APS LTP-II). Preliminary tests were conducted (in January and May 2012) using the optical system configuration of the Nanometer Optical Component Measuring Machine (NOM) developed at Helmholtz Zentrum Berlin (HZB)/BESSY-II. With a flat Si mirror that is 350mm long and has 200nradrms nominal slope error over a useful length of 300mm, the system provides a repeatability of about 53nrad. This value corresponds to the design performance of 50nradrms accuracy for inspection of ultra-precise flat optics.