The hyperfine structures of <sup>206</sup>Bi (6.3 day) and <sup>209</sup>Bi (10<sup>18</sup> year) have been measured with the use of a 10-m focal-length Czerny-Turner grating monochromator, and the isotope shift between them was obtained. The radioactive isotope 206.Bi was produced by proton bombardment of 208.Pb. A radiochemical procedure was developed for separating the radioactive bismuth from the lead target and transferring it into an electrodeless lamp. The light source contained about 10 ng of 206.Bi. From an analysis of the hfs in the 6p3. 4.S<sub>1/2</sub> and 6p2.7s 4.P<sub>1/2</sub> states, a value of 121±13 mK was obtained for the 206.Bi–209.Bi isotope shift in the 3067-Å resonance line. The possible effect on this value of perturbations by other isotopes is discussed.
P. C. MAGNANTE and H. H. STROKE, "Isotope Shift between 209Bi and 6.3-day 206Bi," J. Opt. Soc. Am. 59, 836-841 (1969)