CHIRPED MULTILAYER COATINGS FOR INCREASED X-RAY THROUGHPUT

Chirped Mo-Si multilayer coatings, where the multilayer period is syst ematically varied throughout the deposition process, exhibit an increa sed x-ray bandwidth at normal incidence with a corresponding increase in the integrated reflectance of as much as 20% at lambda approximatel y 13 nm. The increased bandwidth is accompanied by a slight reduction in peak reflectance. The relation between the integrated and peak refl ectance is used to determine the chirp required to optimize the x-ray throughput of a multiple-element optical system.