Experiments at the Si K absorption edge. (a) The real parts of the refractive indices for an Si substrate, PS, SEBS and water at the Si K absorption edge, as calculated from reported values of the anomalous scattering factors and densities. For SEBS, the density was determined from the critical-angle measurements with Cu Kα1 radiation. The vertical lines mark X-ray energies of 1.770, 1.830 and 1.837 keV. The bottom part of the figure shows GISAXS patterns measured with X-rays with photon energies of (b) 12.4 keV, (c) 1.770 keV and (d) 1.837 keV. The positions marked by broken lines correspond to the calculated positions of the critical angle for (1) Si, (2) SEBS and (3) both. Adapted from Okuda et al. (2012).