Abstract

We use the Kramers–Kronig dispersion relation to calculate the real part of the index of refraction of neon and argon for energies ranging from zero into the x-ray region. The cross sections of these gases are known experimentally to an accuracy of about 5%. We also use calculations of the oscillator strengths of the discrete transitions. We first correct the values of the cross sections to make them agree with the very accurate experimental value of the polarizability, and with the Thomas–Reiche–Kuhn sum rule.

Our results for the index of refraction generally agree with existing theoretical calculations and experimental measurements to within 10%.

© 1968 Optical Society of America

Neon Transition Probabilities*

R. A. Lilly and J. R. Holmes
J. Opt. Soc. Am. 58(10) 1406-1409 (1968)

Photoionization Cross Sections of Neon from Threshold to 200 Å

James A. R. Samson
J. Opt. Soc. Am. 55(8) 935-937 (1965)

Bandwidth Dependence of Measured uv Absorption Cross Sections of Argon*

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Determination of the Absorption Cross Section of the Laser Transitions of the Nd⁺³ Ion in the Nd⁺³:SeOCl₂ System

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J. Opt. Soc. Am. 58(8) 1054-1056 (1968)

Theoretical Calculation of Atomic Spectra Using Digital Computers*

Robert D. Cowan
J. Opt. Soc. Am. 58(6) 808-818 (1968)