Abstract

Many luminescent substances show a fatigue effect or loss of efficiency with continued exposure to ultraviolet light. Measurements made on several inorganic phosphors, organic substances such as anthracene and on fluorescent canary glass, showed that the losses increased with time and intensity of irradiation. The phenomenon can be demonstrated with liquids as well as with solid crystalline material. Equilibrium conditions were attained in about ten minutes. Both short ultraviolet radiations at 2537A and longer radiations at 3650A were used. The recovery from fatigue was demonstrated with a number of substances. Several samples of luminescent sulfides were exceptions in that they did not show the fatigue phenomenon. Decreases in light output can also be demonstrated with cathode-ray excitation.

© 1942 Optical Society of America

The Response of Several Fluorescent Materials to Short Wave-Length Ultraviolet Radiations

N. C. Beese
J. Opt. Soc. Am. 29(7) 278-282 (1939)

An Investigation of the Properties and Applications of the Geiger-Müller Photoelectron Counter*

O. S. Duffendack and W. E. Morris
J. Opt. Soc. Am. 32(1) 8-24 (1942)

Luminescent Pigments and Coatings*

G. F. A. Stutz
J. Opt. Soc. Am. 32(10) 626-628 (1942)

Reflection-Transmission Relationships in Sheet Materials

Herbert F. Launer
J. Opt. Soc. Am. 32(2) 84-93 (1942)

The Fluorescence of Phosphors in the Rare Gases

Gorton R. Fonda and Hans Huthsteiner
J. Opt. Soc. Am. 32(3) 156-160 (1942)