Fabrication and testing of grazing incidence mirrors for hard x rays

摘要

Diamond-cut flat mirrors with controlled surface roughness are evaluated by measuring the angular distributions of x-ray scattering in the hard x-ray region (1 Angstrom). The reflection profile, for a glancing angle of 1 mrad, has a sharp peak with a FWHM of less than 10 $mu@rad. This has a potential application to a hard x-ray microprobe with a sub-$mu@m spot. The reflection profile includes subpeaks due to surface undulations of about a 6 mm period equal to the ball screw lead of the cutting machine. However, small pitches in the surface roughness, such as the tool feed (15 $mu@m), do not affect the peak profile of the reflection beam, because the diffraction angle is detected at more than 1 mrad away from the specular reflection angle.