Focusing of hard synchrotron radiation by a refracting glassy carbon lens

The first experimental study of focusing synchrotron radiation by a parabolic planar glassy-carbon lens is presented. The lens consists of four biconcave single lenses with a curvature radius of 0.2 mm and a relief height comparable with the lens aperture (similar to1 mm). One lens gives rise to the formation of a linear focus with a length comparable with the height of a parabolic profile. The use of two lenses in the cross geometry provides the formation of a pointlike focus. The experiment was performed with the use of synchrotron radiation from the bending magnet BM-5 at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France. The monochromated synchrotron radiation with an energy of 12.2 keV was focused at a distance of 19 m from the lens. The causes that gave rise to focus broadening in comparison with the focus following from the theory of an ideal lens are discussed