PARTICLE-VIBRATION COUPLING IN 209PB

The level structure of 209Pb has been investigated by means of proton and gamma-ray spectra from the reaction 208Pb(d, p,γ)209Pb. The decay scheme of the low-lying levels has been established with the aid of (γ)(p) coincidence measurements. Using a high-resolution magnetic spectrograph, 26 levels in 209Pb have been found below 4.5 MeV of excitation energy. The angular distributions of the corresponding proton groups were studied and l-values suggested for some of the levels. The observed level structure of 209Pb is compared with that calculated on the basis of a weak-coupling model. The structure of the low-lying states is very satisfactorily explained by the model. At energies well above 3 MeV, the interpretation is complicated by the fact that a large number of levels is populated by small fractions of single-particle strength, possibly from the shell above. © 1969.