BROAD-BAND HARD X-RAY REFLECTORS

Interest in optics for hard X-ray broad-band application is growing. I n this paper, we compare the hard X-ray (20-100 keV) reflectivity obta ined with an energy-dispersive reflectometer, of a standard commercial gold thin-film with that of a 600 bilayer W/Si X-ray supermirror. The reflectivity of the multilayer is found to agree extraordinarily well with theory (assuming an interface roughness of 4.5 Angstrom), while the agreement for the gold film is less, The overall performance of th e supermirror is superior to that of gold, extending the band of refle ction at least a factor of 2.8 beyond that of the gold, Various other design options are discussed, and we conclude that continued interest in the X-ray supermirror for broad-band hard X-ray applications is war ranted. (C) 1997 Elsevier Science B.V.