New contrasts in the topographs of quartz obtained with the third generation synchrotron

The synchrotron radiation delivered by the topography beam line of the European Synchrotron Radiation Facility (ESRF) was used to study quartz crystals and resonators. Several experimental set-ups taking advantage of the unique properties of the beam (very small divergence, extended spectra, time structure, etc.) were used to enhance the sensibility of detection of strain gradients due either to defects or to vibration modes. New contrasts were observed at the limits of the Z growth sectors (and also in the X or 8 sectors) in the most perfect crystals obtained by the crossed growth technique. In several samples of synthetic quartz, we have observed in the Z growth region, contrasts normal to the growth direction and resembling those of stacking faults. The increase of the sensibility of the stroboscopic technique has allowed to observe an important feature concerning the interaction of the vibration mode with the mounting clips (3rd overtone plano-convex resonator). The experiments and the results obtained are, in their principles, similar to those previously reported (1989) but the new experimental diffraction conditions bring an important increase of the sensibility of detection