We have developed a new depth-graded multilayer system comprising W and SiC layers, suitable for use as hard x-ray reflective coatings operating in the energy range 100–200 keV. Grazing-incidence x-ray reflectance at <i>E</i> = 8 keV was used to characterize the interface widths, as well as the temporal and thermal stability in both periodic and depth-graded W/SiC structures, whereas synchrotron radiation was used to measure the hard x-ray reflectance of a depth-graded multilayer designed specifically for use in the range <i>E</i>~150–170 keV. We have modeled the hard x-ray reflectance using newly derived optical constants, which we determined from reflectance versus incidence angle measurements also made using synchrotron radiation, in the range <i>E</i> = 120–180 keV. We describe our experimental investigation in detail, compare the new W/SiC multilayers with both W/Si and W/B<sub>4</sub>C films that have been studied previously, and discuss the significance of these results with regard to the eventual development of a hard x-ray nuclear line telescope.
© 2003 Optical Society of America
David L. Windt, Soizik Donguy, Charles J. Hailey, Jason Koglin, Veijo Honkimaki, Eric Ziegler, Finn E. Christensen, Hubert Chen, Fiona A. Harrison, and William W. Craig, "W/SiC X-Ray Multilayers Optimized for Use Above 100 KeV," Appl. Opt. 42, 2415-2421 (2003)