Spectral characterisation of aperiodic normal-incidence Sb/B4C multilayer mirrors for the lambda 124 angstrom range

摘要

Three broadband aperiodic Sb/B4C multilayer mirrors were synthesised for the purposes of soft X-ray optics and spectroscopy in the wavelength range beyond the L-edge of Si (lambda 124 angstrom), and their reflection spectra were measured. The multilayer structures were optimised for maximum uniform reflectivity in the ranges 100 - 120 angstrom, 95 - 105 angstrom and 90 - 100 angstrom. The reflection spectra were recorded using a laboratory laser-plasma radiation source and an electronic detector with a 2D spatial resolution (a CCD matrix with 13 x 13 mm sized pixels). The experimental spectra are compared with theoretical calculations. The effect of lower antimony and B4C layer densities on the reflection spectra is discussed.