Translator Disclaimer
11 October 2011 High-resolution x-ray characterization of mosaic crystals for hard x-and gamma-ray astronomy
Author Affiliations +
We have analyzed GaAs, Cu, CdTe, and CdZnTe crystals as possible optical elements for hard x-ray lenses for x-ray astronomy. We used high resolution x-ray diffraction at 8keV in Bragg geometry and Laue transmission diffraction at synchrotron at energies up to 500 keV. A good agreement was found between the mosaicity evaluated in Bragg diffraction geometry with x-ray penetration of the order of few tens micrometers and in Laue transmission geometry at synchrotron. All the analyzed crystals showed mosaicity values in a range between a few to 150 arcseconds and suitable for the application. Nevertheless -CdTe and CdZnTe crystals exhibit non-uniformity due to the presence of low angle grain boundaries; -Cu crystals exhibit mosaicity of the order of several arcminutes; they indeed suffer by a severe cutting damage that had to be removed with a very deep etching. The FWHM was also rapidly decreasing with the x-ray energy showing that the mosaic spread is not the only origin of peak broadening; -GaAs crystals grown by Czochralski method show mosaicity up to 30 arcseconds and good diffraction efficiency up to energies of 500 keV. The use of thermal treatments as a possible method to increase the mosaic spread is also evaluated.
© (2011) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Claudio Ferrari, Elisa Buffagni, Laura Marchini, and Andrea Zappettini "High-resolution x-ray characterization of mosaic crystals for hard x-and gamma-ray astronomy", Proc. SPIE 8147, Optics for EUV, X-Ray, and Gamma-Ray Astronomy V, 81471F (11 October 2011);

Back to Top