Luminescent Materials for Cathode-Ray Tubes

This paper describes the mantufacture, characteristics, and utilization of three kinds of luminescent materials (phosphors) which are employed in cathode-ray tube screens. The phosphors´ dependence for efficiency upon minute details of manufacture is brought out, and the subject of activators discussed. The different forms of persistence and spectral distribution characteristics with their corresponding usefulness in the oscillographic and television fields are shown. One material, called phosphor No. 1 is recommended for general-purpose cathode-ray tube screens, particularly for visual observation where the highest brilliancy is desired; another, phosphor No. 2, for work where its brilliant phosphorescence is wanted for observing extremely low-frequency phenomena and transients; and the third material, phosphor No. 5, of very short persistence and highly actinic emission, when photographic records are to be taken of the cathode-ray tube trace.