Papers by Author: Yoshiharu Namba

Abstract: A method of straightness error compensation is presented, which is used in ultra-precision machining with nano-scale accuracy for a large mandrel manufacture. A set of measurement system in situ is developed, in which an ultra-smooth glass-ceramic flatness gauge and a non-contact micro displacement sensor with nano-scale resolution were used as a reference and sensor to get the straightness error of machine tool movement. The real straightness error can be obtained after subtracting the surface profile of the gauge from the original straightness error curve. Based on the real straightness error data, a new NC program was made for compensating the error from the axis movement of machine tool. As a result, after straightness error compensation, the straightness errors of two axes of ultra-precision machine tool are 68nm/400mm and 54nm/300mm respectively.

Abstract: Grazing incidence optics used in soft X-ray microscopes require supersmooth surface and highly accurate figure. We considered the fabrication of a Wolter type I mirror, one of grazing incidence optics, with axial-symmetric inner reflecting surfaces using single-point diamond turning. Electroless nickel was chosen as reflecting material Cutting conditions for machining the inner reflecting surface were restricted because of long arm of a single-crystal diamond tool. The machined Wolter type I mirror had approximately 270 nm P-V in figure error and 3 nm Ra in surface roughness. The direct-machined Wolter type I mirror could be successfully used in a soft Xray microscope based on laser-produced X-ray source.