DEVELOPMENT AND SURFACE EVALUATION OF LARGE SIC X-RAY MIRRORS FOR HIGH-BRILLIANCE SYNCHROTRON-RADIATION

Flat SIC mirrors coated with Pt, of which size are 800x50 mm(2) and 10 00x140 mm(2) in area are developed for high-brilliance synchrotron rad iation. The large mirrors are well polished over the entire area from the viewpoint of surface roughness for application to the use for the synchrotron radiation beamline. The performance of the large mirror su rface is evaluated by the measurements of not only reflectivity near t he critical angle but also of the angle-resolved scattering (ARS) curv e as a function of mirror surface position at several glancing angles with CuK alpha X-rays from a rotating target at the 30-m-long X-ray be amline facility of ISAS. By analyzing the ARS curves the power spectra l density functions are derived as a function of the surface wave numb er. It is suggested that the large mirror may have a fractal surface f inish like that of small mirrors. Evaluation of the longitudinal mirro r curvature on the order of 10 km from the reflected beam profile widt h is also described. The results are compared with the measurements of the laser interferometers.