Hyperfine Structure and Nuclear Spins of Tungsten and Tellurium

Abstract

By the use of enriched isotopes, hyperfine structure in the optical spectra of ${\mathrm{Te}}^{123}$, ${\mathrm{Te}}^{125}$, and ${\mathrm{W}}^{183}$ has been observed. Milligram amounts of the isotopes were used in a modified Schüler hollow-cathode discharge tube. In the visible region, 4000 to 6000A, about a dozen lines of singly ionized tellurium showed hyperfine structure, all of them giving just two components for the odd isotope. ${\mathrm{Te}}^{123}$ and ${\mathrm{Te}}^{125}$ gave identical structures except for a scale factor, the total splitting of the lines of ${\mathrm{Te}}^{123}$ being about 88 percent of that of ${\mathrm{Te}}^{125}$. In the spectrum of neutral tungsten, all of the lines which show the isotope shift for natural tungsten gave just two components with highly enriched ${\mathrm{W}}^{183}$. The number of hyperfine-structure components, namely two, gives for ${\mathrm{Te}}^{123}$, ${\mathrm{Te}}^{125}$, and ${\mathrm{W}}^{183}$ a nuclear spin of ½. This was also verified by intensity measurements.