Hyperfine-structure measurements on trapped Pb ii

The 6${\mathit{P}}_{3/2}$-6${\mathit{P}}_{1/2}$ magnetic dipole resonance transition in ${\mathrm{Pb}}^{+}$ has been observed by cw laser excitation of an ion cloud stored in a Paul trap and subsequent detection of the fluorescence radiation. From the hyperfine-structure splitting of the spectrum we determine the A factor for the ground state, A(${\mathit{P}}_{1/2}$)=12.967(13) GHz, and the excited state, A(${\mathit{P}}_{3/2}$)=0.580(3) GHz. From a contamination of ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ in our sample we derived the ${}_{}{}^{207}{}_{}{}^{}\mathrm{Pb}_{}^{+}{}_{}{}^{}$${\mathrm{-}}^{208}$${\mathrm{Pb}}^{+}$ isotope shift [Δν=311(14) MHz]. A small electric quadrupole admixture giving rise to a ΔF=2 component in the spectrum has been determined to be 6.4(0.5)% of the total transition amplitude.