Predicting glitches of intensity in single-crystal diamond CRLs

Effective optics is crucial to realize all the possibilities and fully reveal the potential of 4th generation synchrotron sources. Compound Refractive Lenses (CRLs) are commonly used for focusing X-rays at synchrotrons due to easy alignment and good focusing efficiency. Diamond CRLs have low absorption, high heat conductivity and are well reproducible, that makes such lenses a perfect candidate for a different type of experiments that require high focusing. Unfortunately, optics, made of single-crystal material, has one drawback that was recently reported - intensity modulation at certain energies in the transmission spectrum. This issue is well known in X-ray spectroscopy and is called “diffraction loss” or “glitch effect”. It is especially bad for spectroscopic experiments, where a certain energy range has to be scanned. However, glitches affect not only spectroscopic experiments – they are often present in the transmission spectrum of single-crystal materials. Therefore it is necessary to understand the formation of glitches and to be able to predict glitches for any experimental conditions. In this paper, we present an algorithm that can determine the precise orientation of the lens solely from the measured spectrum of glitches and analytical approach to refine the actual orientation of the lens and cell constant. Moreover, we propose a method of "getting rid" of glitches for each energy with the help of a small tilt of the lens.