Optic hutch II: The mirror

The toroidal mirror, situated downstream of the monochromator about 26.5 m from the source, collects up to 1.5 mrad horizontally and 0.3 mrad vertically and focuses the X-rays with a demagnification factor of 2.6 onto the fixed detector plane. The mirror consists of two identical segments of 750 mm length each, which are made from Platinum coated Zerodur. The measured mirror radii are 2.95 km and 6.53 cm (fixed values) with slope errors of 0.7 arcsec and 4.3 arcsec in the longitudinal and sagittal direction, respectively. The measured surface roughness is 0.3 nm RMS, and the mirror is set to a grazing angle of 4.74 mrad in order to reflect photons up to 17.9 keV. The mirror segments are held in separate holders and can be aligned relative to each other using 5 degrees of freedom. The two units are mounted onto a common support table which allows to kinematically align the complete segmented mirror relative to the incoming photon beam.