Monochromators for Synchrotron radiation based on SiGe gradient crystals

This work is devoted to the investigation of monochromatization of the dive rgent synchrotron beam at the radiation diffraction by single crystals of s ilicon-germanium solid solutions with the given gradient of the lattice par ameter along the sample surface. It has been shown that such crystals provi de a high spectral resolution and increasing luminosity at a given radiatio n wavelength. The concentration dependence of the lattice parameter of SiGe crystals for compositions from 1 to 12 at % of Ge has been refined. The re al structure of crystals has been analyzed by methods of two-crystal spectr ometer and section topography. The description of the dynamic problem on th e Bragg symmetric diffraction of the divergent beam of the X-ray radiation is represented for the case when the scattering vector is perpendicular to the direction of the lattice parameter gradient of the crystal. (C) 2000 El sevier Science B.V. All rights reserved.