Nuclear Moments of the Isotopes of Lead: Relative Values of the g ( I ) Factors of Pb(207) and T1

As a continuation of the programme that was initiated with the analysis of the hyperfine structure of T1 II,1 the hyperfine structure of Pb III was investigated. The important Pb III lines2 in the visible region were examined by means of a concave and an echelon grating. The structure and intensities of the patterns were interpreted consistently by attributing I = 0 to the two even isotopes Pb(206) and Pb(208), and I = ½ to the odd isotope Pb(207). This interpretation is in agreement with Kopfermann's3 deductions based on the structure of Pb I and II lines and with Schüler and Keyston's4 inference based on intensity measurements of the lead line λ4058.