Polycapillary-based X-ray optics

Abstract Glass capillaries can guide a broad energy range of X rays by means of multiple total reflections. Arrays of curved polycapillary fibers have many potential functions, including beam collection and focusing, beam collimation and energy filtering. The transmission efficiency and exit divergence of X rays guided through straight and bent polycapillary fibers have been measured for CuK α radiation and bremsstrahlung 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 of 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 flux within a microsteradian is predicted.