Experimental study of polycapillary optics for hard x-ray applications

Capillary optical elements have been systematically investigated to evaluate their possible use for hard x-ray applications. Transmission efficiency and angular divergence of polycapillary fibers as well as a complete capillary system have been measured for x-ray energy up to 75 keV. Limitations of current fabrication process are defined. A coating approach to enhance the transmission parameters for polycapillary fibers has been investigated. Significant improvement in transmission efficiency is demonstrated experimentally. Results of simulations for coating enhancement are also presented. Future improvements of polycapillary optics are discussed.