Observation of horizontal focusing of X-rays using a toothed-crystal monochromator

The behaviour of a toothed-crystal monochromator for synchrotron radiation was studied for the first time on the GILDA CRG beamline at the ESRF. A new kind of horizontal focusing was observed which may be attributed to the properties of inclined diffraction. We have also observed a vertical focusing of the beam, the nature of which remains unexplained.