Excitation of Pb206, Pb207, Pb208, and Bi209 by inelastic electron scattering

Abstract

High-resolution measurements of the differential cross sections for inelastic scattering of 28- to 73-MeV electrons by Pb206, Pb207, Pb208, and Bi209 nuclei have been analyzed by using a distorted-wave code to extract reduced nuclear radiative transition probabilities [B(EL)'s], and transition radii. The use of an irrotational and incompressible vibrating-liquid-drop model resulted in good fits to the data. In agreement with de-Shalit's weak-coupling core-excited state model, the B(EL)'s were found to be equal for the three lead isotopes within an experimental error of about 6% for the E2 excitations at about 4.1 MeV, and for the E4's at about 4.3 MeV. For all four isotopes the B(E3)'s at about 2.6 MeV were equal. Excitations of Pb208 at 5.25 MeV (3- or 4+), 5.6 MeV (3-), and 6.2 MeV (2+ or 0+) were observed. No strong E2 excitation of Pb208 was identified between 6.2 and 18 MeV. A discussion of model and parameter dependence of the B(EL)'s and transition radii is given. © 1968 The American Physical Society.