Special features of synchrotron radiation as applied to X-ray energy-dispersive diffraction - a review

Energy-dispersive diffraction utilizes white radiation and a semiconductor detector for the energy (wavelength) analysis of the scattered X-rays. The scattering angle is fixed during a measurement and all reflections are recorded simultaneously. Recent experiments have shown that synchrotron radiation in many respects is an ideal source for energy-dispersive diffraction. For quantitative structural analysis it is of great importance that both the spectral distribution and the polarization of the radiation from a storage ring can be calculated from the machine parameters. Resolution considerations show that an optimum scattering angle can be found depending on the detector resolution and the divergence of the incident and scattered beams. Special attention has to be given to the detector performance at high count rates. The energy-dispersive method facilitates studies of samples in special environments. Powder spectra taken at high temperatures and high pressure are shown as examples. Some preliminary results from single crystal diffraction are also discussed. (Auth)