The Far Ultraviolet Reflectivities of Metallic Films

The reflectivities of evaporated films of aluminum, copper, silver, and beryllium have been measured spectrographically in the region 1200–2200A before the films were exposed to air. Copper reflection was considerably higher before contamination by air than afterward; the other metals showed no effect. The pronounced minimum in beryllium reflectivity found by previous investigators did not occur here; it is believed that this minimum is due to a thin film of tungsten evaporated over the beryllium.