Isotope Shift between 209 Bi and 6.3-day 206 Bi*

The hyperfine structures of 206Bi (6.3 day) and 209Bi (1018 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 206Bi was produced by proton bombardment of 208Pb. 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 206Bi. From an analysis of the hfs in the 6p3 S412 and 6p27s P412 states, a value of 121±13 mK was obtained for the 206Bi–209Bi isotope shift in the 3067-A resonance line. The possible effect on this value of perturbations by other isotopes is discussed.