The influence of beryllium microstructure and impurities on the CRL x-ray optical properties

The paper is focused on the comparison of different beryllium materials quality grades for coherent X-ray applications and the influence of the beryllium microstructure on the imaging and optical properties of compound refractive lenses. The main optical characteristics for a wide range of beryllium grades are presented. The process of formation of speckle-pattern from the material microstructure is experimentally investigated at the ESRF ID06 beamline in the X-ray coherent transmission microscopy mode. Comparative studies on focusing 2.5 keV X-ray beam using refractive lenses made of different beryllium grades were carried out. The paper includes recommendations on beryllium refractive lenses and beryllium windows manufacturing processes by using different beryllium grades for various applications of X-ray optics for the 3rd and 4th generation synchrotrons.