High-quality synthetic diamonds for SR application

Synthetic diamond single crystals grown by the temperature gradient method using BARS technique have been characterized by means of X-ray diffraction. X-ray transmission topography revealed high lattice perfection of the crystals studied. From rocking curves measurements it was found that the width for C(2 2 0) reflection varies in the range 5-20 arcsec and depends on the diamond's growth conditions. Application of the diamond crystals as quarter-wave plates for synchrotron X-rays has been tested. The achieved degree of circular polarization is 0.96 at Fe K-edge region. These crystals permit one to apply diamond quarter-wave plates in experiments with divergent and tunable monochromatic beams of bending magnets.