Abstract

Absolute photon-flux measurements in the vacuum ultraviolet have been extended to short wavelengths by use of rare-gas ionization chambers. The technique involves the measurement of the ion current as a function of the gas pressure in the ion chamber. The true value of the ion current, and hence the absolute photon flux, is obtained by extrapolating the ion current to zero gas pressure. Examples are given at 162 and 266 Å. The short-wavelength limit is determined only by the sensitivity of the current-measuring apparatus and by our present knowledge of the photoionization processes that occur in the rare gases.

© 1974 Optical Society of America

Absolute Intensity Measurements in the Vacuum Ultraviolet*†

James A. R. Samson
J. Opt. Soc. Am. 54(1) 6-15 (1964)

Measurement of Absolute Radiation Intensities in the Vacuum-Ultraviolet Region

Einar Hinnov and Fritz W. Hofmann
J. Opt. Soc. Am. 53(11) 1259-1265 (1963)

Metal Photocathodes as Secondary Standards for Absolute Intensity Measurements in the Vacuum Ultraviolet*

R. B. Cairns and J. A. R. Samson
J. Opt. Soc. Am. 56(11) 1568-1573 (1966)

Photoionization and Absorption Cross Sections of H₂ and D₂ in the Vacuum Ultraviolet Region

G. R. Cook and P. H. Metzger
J. Opt. Soc. Am. 54(8) 968-972 (1964)

Absolute measurement of the extreme UV solar flux

Robert W. Carlson, H. S. Ogawa, E. Phillips, and D. L. Judge
Appl. Opt. 23(14) 2327-2332 (1984)