POLYCAPILLARY-BASED X-RAY OPTICS

Glass capillaries can guide a broad energy range of X rays by means of multiple total reflections. Arrays of curved polycapillary fibers hav e many potential functions, including beam collection and focusing, be am collimation and energy filtering. The transmission efficiency and e xit divergence of X rays guided through straight and bent polycapillar y fibers have been measured for CuK(alpha) radiation and bremsstrahlun g radiation from a point X-ray source. Experimental results have been compared with ray-tracing simulations. The good agreement between the two indicates that simulations can reliably describe the propagation o f X rays through smooth glass capillaries. The same simulation program has been used to characterize the performance of a capillary-based X- ray lens which collects and collimates X rays from an anode source for use in diffraction applications. A 250-fold enhancement of photon flu x within a microsteradian is predicted.