Abstract

Photomultipliers sensitized to the extreme ultraviolet by coating with a layer of a fluorescent material were found satisfactory for the measurement of radiation intensities at least down to 850 angstroms. The relative spectral quantum efficiencies of sodium salicylate, pump oil, anthracene, calcium and cadmium tungstates, and Eastman ultraviolet fluorescing lacquer were measured by comparison against a thermocouple, using a vacuum monochromator. Sodium salicylate was found to be the best suited for sensitizing a photomultiplier, since it had high sensitivity to the extreme ultraviolet and low sensitivity to long wavelength stray light. Heterochromatic photometry can be carried out with this combination, since the quantum efficiency of sodium salicylate was approximately independent of wavelength over the range 900–2300A. The properties of stilbene, phenanthane, and several miscellaneous phosphors were also measured.

© 1951 Optical Society of America

Ultraviolet Spectral Sensitivity Characteristics of Photomultipliers Having Quartz and Glass Envelopes*

L. Dunkelman and C. Lock
J. Opt. Soc. Am. 41(11) 802-804 (1951)

Thermocouple Measurements of Spectral Intensities in the Vacuum Ultraviolet*

Donald M. Packer and Charles Lock
J. Opt. Soc. Am. 41(10) 699-701 (1951)

Measurement of Spark Spectrum Intensities in the Vacuum Ultraviolet with the Fluorescence Sensitized Photomultiplier

S. E. Williams, M. R. Meharry, V. W. Maslen, and R. L. Falconer
J. Opt. Soc. Am. 44(8) 654-658 (1954)

Intensity Measurements in the Vacuum Ultraviolet

K. Watanabe and Edward C. Y. Inn
J. Opt. Soc. Am. 43(1) 32-35 (1953)

The Characteristics of Ultraviolet-Sensitized Photographic Plates in the Vacuum Ultraviolet*

Po Lee and G. L. Weissler
J. Opt. Soc. Am. 43(6) 512-515 (1953)