An X-ray focusing monochromator composed of poly-capillary X-ray lenses and highly oriented pyrolytic graphite

An X-ray focusing monochromator is proposed, which is composed of an X-ray source, a highly oriented pyrolytic graphite and two poly-capillary X-ray lenses. Through the function of the front poly-capillary X-ray lens, the X-ray beams diffracted by the highly oriented pyrolytic graphite changed from a linear pattern with high divergence in the vertical direction, to a circular pattern with low divergence, and more X-rays are diffracted than the conventional monochromator of combining an X-ray source with a flat crystal. The post poly-capillary X-ray lens can focus the diffracted X-ray beams with low divergence into a small focal spot with high gain in power density. The results show that the gains of circular apertures with diameters of 320 and 100 μm are 12 and 22, respectively, at a distance of 221.5 mm away from the center of the highly oriented pyrolytic graphite.