Advanced Manufacturing and Smoothing of X-Ray Mirrors

Current domestic end-to-end production of diffraction-limited, curved, long x-ray mirrors cannot meet the required specifications due to manufacturing-induced high- and mid- spatial-frequency errors. This proposal aims to address manufacturing shortfalls and utilize state-of-the-art metrology to mature the manufacture of precision x-ray mirrors within the United States. Through comprehensive attention to each step in the manufacturing chain and novel smoothing techniques, this project’s approach proposes systematic prevention and mitigation of detrimental mid-and high-spatial frequency errors that typically result from tool signatures during manufacturing. By merging process control during single point diamond turning and research using a novel smoothing technique, troublesome errors can be reduced and subsequent mirror surfaces can move towards sub- nanometer level error. The Phase I goals include 1) quantify and optimize the parameters in the generation and diamond turning steps to reduce subsurface damage and subsequent mid-spatial frequency errors and reduce production time, while evaluating success with relevant metrology such as stitching interferometry, white light interferometry, profilometry, and deflectometry; 2) use a data-driven, deterministic approach and relevant metrology tools to apply a novel smoothing-magnetorheological fluid polishing cycle for surfaces readying them for ion beam figure finishing to achieve final, sub-nanometer form error. A metrology round robin will be performed both internally among various metrology instruments, as well as with the Optics and Metrology group at Brookhaven National Laboratory to quantify surface quality and help determine the required direction for a subsequent Phase II effort. Successful completion of a Phase II plan will lead to domestic production of long x-ray mirrors for needs in the synchrotron community, which will help meet public energy and other scientific research goals. In addition, the techniques developed for smoothing mid-spatial frequency errors can be directly employed for many other optics manufacturing applications, including imaging systems for space telescopes, freeform optics for small satellites, directed energy applications, and optics for semiconductor industries.