Thin Films and Their Uses for the Extreme Ultraviolet

Abstract

The transmittance characteristics in the extreme ultraviolet of unbacked films are discussed; data are presented for films of Al, In, Bi, Ge, Si, and certain organic materials. Generally, the metals begin to transmit shortward of their critical wavelengths, determined by the electron eigenloss, and reach maximum transparency at the nearest x-ray edge; to shorter wavelengths regions of transparency exist between the other x-ray edges. Their use in order-sorting, and for eliminating long-wavelength stray light, is illustrated with laboratory spectra and solar spectra obtained from rockets.