Development of NiC multilayer coatings for extended broadband X-ray imaging

Next-generation astronomical hard X-ray telescopes will require new optical coating technologies to extend the current imaging capabilities into the 100’s of keV. Missions such as NuSTAR and Hitomi have successfully demonstrated the utility of multilayer coated grazing incidence optics up to 80 keV. While the well-studied and characterized PtC and WSi coating combinations offer large reflectivity and, consequently, improved effective area in this energy range, new coating materials and designs are needed to achieve the required performance beyond the 80 keV limit. The High-Energy X-ray Probe (HEX-P) proposes to implement such novel coatings to achieve a bandpass of 2 to 200 keV. Utilizing the HEX-P baseline multilayer coating designs, we investigate and characterize nickel-based broadband multilayer coatings for use on future hard X-ray missions.