A VIBRATING MONOCHROMATOR FOR THE DIFFRACTION TOPOGRAPHY BEAMLINE OF THE ESRF

A perfect silicon crystal is used at the ESRF as monochromator for mon ochromatic synchrotron diffraction topography. This monochromator prod uces a beam with a narrow range of energy, which is not suitable for s ome experiments. Moreover, the diffracted energy varies spatially on t he monochromatic beam section. A solution to overcome the narrow energ y range and the wavelength dispersion is the use of a vibrating monoch romator. We present in this paper the three-pole electromagnet device used to vibrate, at about 100 Hz, the perfect (110) Si crystal, the re sults on the homogeneity of the vibrations and the x-ray topographs re corded using this method.