The Effect of Hyperfine Structure Due to Nuclear Spin on Polarization of Resonance Radiation

Abstract

The existence of hyperfine structure must be taken into account in calculations of the polarization of resonance radiation based upon Heinsenberg's extension of the principle of spectroscopic stability. Where the hyperfine structures are due to the existence of a nuclear moment their effect upon the polarization of resonance radiation may be calculated. If the nuclear moment of the thallium atom is ½ (in units of $\frac{h}{2\pi }$) as Schüler and Brück suppose the $\lambda \lambda 3776$ and 5350 lines should show no polarization, while $\lambda 2768$ should show 33.3 to 35.1 percent parallel and $\lambda 3530$ 41.8 to 48.8 percent perpendicular to the electric vector of a plane polarized exciting beam. Sodium resonance radiation excited by plane polarized ${\mathrm{D}}_1$ and $D_2$ lines should show 33.3 percent polarization if the nuclear moment is ½ and 16.6 percent if it is 1. The latter value agrees well with 16.3 observed by the writer, but observations on band spectra seem to indicate a higher nuclear moment, according to F. W. Loomis and R. S. Mulliken (Verbal communication to the writer.)