An improved value of the <sup>203</sup>Hg-<sup>198</sup>Hg isotope shift in the 2537 Å <sup>3</sup><i>P</i><sub>1</sub>-<sup>1</sup><i>S</i><sub>0</sub> line of mercury was determined from emission spectroscopy, with mass-separated samples, and from absorption spectroscopy with unenriched pile-produced isotope. The spectroscopic data were analyzed to yield the isotope shift by use of precise hfs interaction constants that we obtained previously from a level-crossing experiment. The new value for the <sup>203</sup>Hg-<sup>198</sup>Hg isotope shift is IS(203-198) = 0.392 ± 0.006 cm<sup>-1</sup>; <sup>203</sup>Hg lies at the lower-wave-number side. The experiment demonstrates the advantages of absorption spectroscopy for samples of low isotopic purity. The application of this technique to work with small samples is also discussed.
© 1975 Optical Society of America
O. Redi and H. H. Stroke, "Isotope shift of 47-day 203Hg," J. Opt. Soc. Am. 65, 1-5 (1975)