A Theoretical Attempt to Predict the Excited States of Nuclei in the Neighbourhood of²⁰⁸Pb

208 Pb has a double closed shell of 82 protons and 126 neutrons The classification of the lowest excited states of 207 Pb, 207 Tl, 209 Pb, 209 Bi, which differ by one nucleon, should thus follow the single-particle model closely. The attempt is made to classify the lowest excited states of 206 Pb, 206 Tl, 206 Hg, 210 Pb, 210 Bi and 210 Po, which differ by two particles, in terms of the one-particle model, taking the interaction of the two particles as a perturbation Considerable uncertainties in the order of the energy levels remain, but some definite conclusions are possible The existence of an isomeric state of 210 Bi (RaE) with very high spin ( I =8?) is predicted. This fits in with known facts about the alphaparticle emitting isomeric state. The method can also be applied to 208 Tl, 208 Bi and the excited states of 208 Pb which arise by lifting one nucleon into the next shell, leaving a hole. It meets with considerable success for 208 Tl Discrepancies with known facts in the case of 208 Pb suggest a more complex picture, according to which the first excited state would have I =0 and even parity. Such a state has never been observed, but its existence is not completely excluded by observation.