Aspheric Surface Fabrication in nm-level Accuracy by Numerically Controlled Plasma Chemical Vaporization Machining (CVM) and Elastic Emission Machining (EEM)

Abstract

We established an efficient ultra-precision figuring process in which a numerically controlled plasma chemical vaporization machining (NC-PCVM) and a numerically controlled elastic emission machining (NC-EEM) are utilized serially. Intensity images of the X-rays reflected by total reflection mirrors greatly fluctuates with respect to the figure error having spatial wavelength ranging from the submillimeter to 10mm. In the present study, elliptical mirrors for the Kirkpatrick-Baez (K-B) focusing unit was manufactured by NC-PCVM and NC-EEM, and figure accuracy higher than 3nm (p-v) was achieved over the spatial wavelength range longer than 0.5mm. The focusing property was evaluated at the BL29XUL of SPring-8, and spot size of 0.2×0.2 μm² (FWHM) was realized at 15keV.