ANALYZING POWER MEASUREMENTS FOR BI-209(N,N) AT 6 AND 9 MEV AND CONSISTENT DISPERSIVE OPTICAL-MODEL ANALYSES FOR N-209 AND N+PB-208 FROM -20 TO +80 MEV(BI)

High-accuracy measurements of A(y)(theta) data for elastic scattering for n + Bi-209 have been performed at 6 and 9 MeV. The data are incorp orated into a large database of sigma(theta), A(y)(theta), and sigma(T ) for n + Bi-209 covering the energy range 1.0-8.0 MeV. A complementar y database is constructed for n + Pb-208 and a dispersive optical-mode l analysis is performed for both scattering systems while constraining many of the parameters to be identical for both systems. A good repre sentation of both databases is obtained with conventional geometry and spin-orbit parameters. The Pb-208 model predicts quite well the measu red energies of valence single-particle and single-hole bound states. Occupation probabilities and spectroscopic factors for the same bound states are also calculated. Finally, a fully constrained model is pres ented in which the only differences between the n + Pb-208 and the n Bi-209 systems are the Fermi energy and the isospin dependence in the real volume potential.