Multilayer X-ray optics for energies E > 8keV and their application in X - ray analysis

摘要

Performance of Ni/C, Ni/B_4C, Mo/B_4C and W/B_4C multilayers in the energy range E>8keV is considered by simulation of X-ray reflectivity and resolution (FWHM) of 1st order Bragg reflection at three different photon energies. The results indicate, that Ni/C and Ni/B_4C multilayers show highest theoretical reflectivities of R > 80percent for Cu Kalpha-radiation and also above the Mo K-edge (E=20.04 keV) at 30 keV. For Mo Kalpha-radiation a reflectivity of R > 90percent for Cu Kalpha-radiation and also above the Mo K-edge (E=20.04 keV) at 30keV. For Mo Kalpha-radiation a reflectivity of R>90percent can be achieved by the use of Mo/B_4C multilayers. For applications, where period thicknesses d < 3 nm and high reflectivities are required W/B_4C multilayers can be used. Theoretical values are compared with X-ray reflectometry results, which were executed at 75 period Ni/C, Ni/B_4C and Mo/B_4C multilayers, fabricated by pulsed laser deposition (PLD) technology on Si substrates. Amorphous or nanocrystalline structures of single layers, smoothest interfaces and high reproducibility of single layer thickness across the entire layer stack are the results of this high precision PLD process.