Optical performance of materials for X-ray refractive optics in the energy range 8 – 100   keV

A quantitative analysis of the crucial characteristics of currently used and promising materials for X-ray refractive optics is performed in the extended energy range 8 – 100   keV. According to the examined parameters, beryllium is the material of choice for X-ray compound refractive lenses (CRLs) in the energy range 8 – 25   keV. At higher energies the use of CRLs made of diamond and the cubic phase of boron nitride (c-BN) is beneficial. It was demonstrated that the presence of the elements of the fourth (or higher) period has a fatal effect on the functional X-ray properties even if low-Z elements dominate in the compound, like in YB66. Macroscopic properties are discussed: much higher melting points and thermal conductivities of C and c-BN enable them to be used at the new generation of synchrotron radiation sources and X-ray free-electron lasers. The role of crystal and internal structure is discussed: materials with high density are preferable for refractive applications while less dense phases are suitable for X-ray windows. Single-crystal or amorphous glass-like materials based on Li, Be, B or C that are free of diffuse scattering from grain boundaries, voids and inclusions are the best candidates for applications of highly coherent X-ray beams.

Source: Journal of Synchrotron Radiation - October 10, 2016 Category: Physics Authors: Serebrennikov, D. Clementyev, E. Semenov, A. Snigirev, A. Tags: X-ray optics refractive lenses X-ray windows optical performance research papers Source Type: research