ENERGY-DISPERSIVE DIFFRACTION WITH SYNCHROTRON-RADIATION AS A PROBE OF THE SOURCE AND MAGNETIC FORM-FACTORS

Self-consistent resolving of a powder diffraction pattern to the Bragg reflections and background is discussed. This is applied in energy di spersive diffraction, and the relation between the integrated Bragg re flection and the spectral flux of the incident beam is given. The meth od is used for determination of the spectral brightness of several syn chrotron radiation sources of the ESRF, and it turns out to be a sensi tive probe of the emittance of the source and the wiggler held. The de gree of circular polarization is measured using the magnetic contribut ion to the Compton scattering cross-section of ferromagnetic iron. Whi te beam diffraction from a nearly perfect iron crystal shows an enhanc ement of the magnetic signal near the centre of the reflection. This i s attributed to changes of polarization and absorption in dynamical di ffraction.