Abstract

A method of evaluation of the optical cross sections, i.e., cross sections for broadening collisions between excited atoms and foreign molecules, from experimental intensity-density data is described. This method utilizes the analytical expressions of the asymptotes to the theoretical intensity-density curves at very low, and at very high densities of the emitting atoms. Only relative intensity measurements are necessary for the evaluation of the cross sections. An intensity-density graph for the Na5890 line is constructed from photoelectric measurements of the total line intensities, emitted from a Lundegårdh-type acetylene-air flame. The optical cross section for sodium corresponding to this line is found to be 64 square angstroms. A brief discussion of the possibilities of utilizing this method for the determination of the degrees of dissociation of metal salts in the flame, or the evaluation of absolute and relative f values of the spectral lines is included at the end of the paper.

© 1957 Optical Society of America

Optical Cross Sections from Intensity-Density Measurements*

Einar Hinnov and Hedwig Kohn
J. Opt. Soc. Am. 47(2) 156-162 (1957)

Optical Cross Section of Resonance Lines Emitted by Flames under Conditions of Partial Thermal Ionization*†

Fritz W. Hofmann and Hedwig Kohn
J. Opt. Soc. Am. 51(5) 512-521 (1961)

Precision Determination of the Velocity of Light Derived from a Band Spectrum Method. III*

D. H. Rank, A. H. Guenther, J. N. Shearer, and T. A. Wiggins
J. Opt. Soc. Am. 47(2) 148-150 (1957)

Critical Comment on a Method for Determining Electron Trap Depths

C. H. Haake
J. Opt. Soc. Am. 47(7) 649-652 (1957)

Study of Optical Diffraction Images at Microwave Frequencies*

M. P. Bachynski and G. Bekefi
J. Opt. Soc. Am. 47(5) 428-438 (1957)