The use of focusing X-ray systems depends upon the specular reflection of grazing incidence. These systems require mirrors with both excellent surface figure and superior surface finish. In order to obtain an efficient predictable method of fabricating such optics, Perkin-Elmer's computer-controlled polishing techniques have been adapted for grinding and polishing cylindrical mirrors. This process accurately controls the time that the tool polishes at each surface location to achieve the prescribed surface material removal.
Robert A. Jones,
"Automated Cylindrical Polishing Of Grazing Incidence X-Ray Mirrors", Proc. SPIE 0316, High Resolution Soft X-Ray Optics, (24 March 1982); doi: 10.1117/12.933121; https://doi.org/10.1117/12.933121