Far-UV reflectance of UHV-prepared Al films and its degradation after exposure to O_2

The far-ultraviolet reflectance of aluminum films prepared and maintained under ultrahigh-vacuum conditions was measured for wavelengths ranging from 82.6 to 120.0 nm. The degradation of the reflectance after exposure to controlled doses of molecular oxygen was also studied. The degradation rate proved to be higher for wavelengths less than 120 nm than previous measurements made at 121.6 nm.