Focusing of synchrotron radiation by compound refractive lenses made from glassy carbon

摘要

Experimental results of synchrotron radiation focusing by parabolic planar compound refractive lenses made of glassy carbon are presented. The lenses with the curvature radii of 5 μm and 200 μm and with the geometric aperture of 40 μm and 900 μm correspondingly were developed with various techniques of laser evaporation. The number of bi-concave elements in the compound lenses was 4, 7 and 200. The planar lenses allow one to obtain linear focuses of the lengths comparable with the depths of their parabolic profiles. Use of two lenses in the cross geometry provides a formation of 2-dimensional focus. The experiments were performed at the ESRF at the bending magnet beamline BM-5. The minimum experimental focus size was as fine as 1.4 μm, which is larger than the theoretical estimation. The reasons of the focus broadening are discussed.