FOCUSING CHARACTERISTICS OF DIAMOND CRYSTAL X-RAY MONOCHROMATORS - ANEXPERIMENTAL AND THEORETICAL COMPARISON

Perfect crystals in transmission (Laue) geometry can be used effective ly for x-ray monochromators, and moreover, perfect Laue crystals show an interesting focusing effect when the incident beam is white and div ergent. This focusing is directly dependent on the incident beam diver gence and on the diffraction profile width of the crystal. The aim of this work is to study whether this property can be used for focusing a synchrotron x-ray beam, and to obtain quantitatively the dimensions o f the resulting monochromatic beam. We have experimentally measured th e size of an undulator beam after diffraction from a diamond crystal i n Lane geometry, and we analyze and explain the results by comparison with ray-tracing simulations. (C) 1995 American Institute of Physics.