Examination of Bragg backscattering from crystalline quartz

The backscattering silicon single crystals normally used for hard X-ray inelastic scattering experiments suffer from parasitic reflections and gaps in photon energy where no backscattering reflection exists. Sapphire has been proposed as a possible alternative, but quartz may have advantages over sapphire at low photon energies (5-12.5 keV). Calculations of energy widths of backscattering reflections up to 30 keV for silicon, sapphire, and quartz are compared. The quartz (11 6 0) reflection is examined at 0.03 degrees from backscattering with 0.8 meV bandwidth beam, and its energy width is measured. Finally, the thermal expansions of quartz and silicon are compared. (c) 2005 Elsevier Ltd. All rights reserved.