Fluorescence of Cadmium Vapor

Abstract

Fluorescence of cadmium vapor.—Cadmium vapor, in an evacuated and carefully baked quartz tube, when illuminated by cadmium, iron and nickel sparks, was found to emit the lines 3262A ($1S-2p_2$), 4678A ($2p_3-1s$), 4800A ($2p_2-1s$) and 5086A ($2p_1-1s$) much more strongly from freshly formed vapor than from older vapor. The line 2289A ($1S-2P$) also appeared slightly stronger in the freshly formed vapor when illuminated by the cadmium spark; it was not excited by iron and nickel sparks. Experiments are described which indicate that it was the freshness of the vapor, not primarily the temperature or pressure, which determined the intensity of the radiation. The effective exciting light was absorbed by glass, hence shorter than 3300A. A Cu spark did not excite the lines, at least in the visible.