Resonant photon scattering from isotopes of lead and bismuth

Nuclear resonant photon scattering from 206207208Pb and 209Bi was measured over excitation regions from 4 MeV to the neutron thresholds with bremsstrahlung beams with endpoint energies of 7.0, 7.5, 7.6, 8.5, and 10.4 MeV. Photons scattered from enriched targets of the lead isotopes and from bismuth were observed with a Ge(Li) detector. Energies and values of gGAMMA02/GAMMA were determined from measurements at 1270 for many levels not previously observed in photon scattering experiments. Spins of levels in 206Pb and 208Pb were determined from angular distribution measurements. Ground-state branching ratios for seven transitions in 208Pb were obtained from a self-absorption experiment. The results are compared with results from earlier spectroscopic studies and from average photon scattering cross section measurements. The spectra of 207Pb and 209Bi are discussed in terms of the excitations of the 208Pb core