Spectral X-Ray Glitches in Monocrystalline Diamond Refractive Lenses

X-ray refractive lenses are widely used optical devices at today synchrotron X-ray sources. In the present paper we demonstrate negative influence of the X-ray diffraction on optical properties of monocrystalline X-ray refractive lenses in operation. Several types of single-crystal diamond lenses were studied in X-ray spectroscopy mode at the European Synchrotron Radiation Facility. X-rays were propagating through individual lenses, stacked together in a row, and the transmitted intensity was measured at different energies. While using the stack of crystallographically co-aligned lenses, we obtained the strong maximal reduction of 35% in an intensity of the outgoing signal. The effect was caused by diffraction losses in the single-crystal diamond and also called "X-ray glitch." The magnitude of the effect was then minimized down to similar to 10% by use of stacks with different crystallographic orientation of individual lenses inside. At the same time, X-ray glitches did not affect any focal spot's size or shape while only arousing the darkening of the focal spot at exact energies of X-ray glitches.