Optical constants for hard x-ray multilayers over the energy range E = 35 - 180 keV

摘要

We have determined experimentally optical constants for eight thin film materials that can be used in hard X-ray multilayer coatings. Thin film samples of Ni_(.97)V_(.03), Mo, W, Pt, C, B_4C, Si and SiC were deposited by magnetron sputtering onto superpolished optical flats. Optical constants were determined from fits to reflectance-vs-incidence angle measurements made using synchrotron radiation over the energy range E=35 - 180 keV. We have also measured the X-ray reflectance of a prototype W/SiC multilayer coating over the energy range E=35 - 100 keV, and we compare the measured reflectance with a calculation using the newly derived optical constants.