Reflective scattering from substrates and evaporated films in the far ultraviolet

Measurements of radiation reflectively scattered from mirror surfaces have been made at the wavelengths 1216 A and 584 A. Several glass and fused silica substrates with differing degrees of surface roughness have been studied, as well as evaporated films of aluminum and gold as a function of film thickness. A relatively small area detector was scanned in angle about the sample, and the detected energy integrated over the scattering angle. The results indicate that fused silica can be polished to a smoother surface than glass, that a smooth substrate is significantly advantageous in obtaining evaporated films having surfaces with low scatter, and that gold films are considerably smoother than aluminum films of equal thickness.