Development of compound refractive lenses for x-rays

One-dimensional and rotationally axisymmetric two-dimensional focusing of x-rays by plastic Compound Refractive Lens (CRL) systems are demonstrated and theoretical aspects behind the design of x-ray CRLs are presented in this report. X-rays between 8 and 19.5 keV were focused by cylindrical CRLs having focal lengths between 35 and 100 cm and fabricated using acrylic (Lucite) and polyethylene. Focusing of x-rays by a spherical CRL was also demonstrated observing a focal length of 85 cm and an effective aperture of about 320 mu m for 8 keV x-rays. The gain, which is the increase in intensity in the image plane relative to the intensity that would have been obtained without a lens on that plane, was 1.5 for 8 keV photons. The gain of this spherical CRL scales about three orders of magnitude higher on undulator beam lines at third generation x-ray sources from the results obtained at the bending magnet x-ray source, with dimensions 445 mu m in the vertical and 1700 mu m in the horizontal, used in this work.