Abstract

Metal coatings such as Au¹ and Ir² will be used as the reflecting surface in current X-ray telescope programs. Likewise, multilayers have been used³ in normal incidence soft X-ray telescopes and are suggested for future grazing incidence telescope projects both near 6-7 keV and in the hard X-ray regime⁴ (10-100 keV). The accurate evaluation of the imaging behaviour of telescopes based on these structures requires characterizing the surface/interface structure on lengthscales from Ångstrøms to mm's. In this paper we present high resolution X-ray scattering data from such surfaces obtained at Cu-K_α1 (8.048 keV), Fe-K_α1 (6.404 keV) and Al-K_α (1.487 keV). We demonstrate that the combination of low, high and ultrahigh resolution scatter measurements can be performed which is capable of detecting scattering from roughness over lenghtscales from a few thousand Å to ~10 mm. The sensitivity of these measurements allow one to detect scattering from roughness having r.m.s. roughness values as small as a few Å in the entire lenghtscale range listed above. The diffuse intensity is mapped completely in reciprocal space for the multilayer structures and the influence of the resolution function is accurately evaluated. The data have been analyzed using the most recent theoretical expressions for the diffuse X-ray scatter from single films and multilayers⁵.

© 1994 Optical Society of America