B(E2) Saturation in the Rare-Earth Region

The quadrupole interactions between neutrons and protons are calculated using Nilsson +BCS model for the neutron-rich even-even rare-earth nuclei. This is used to study the saturation of B(E2)'s in this mass region. The neutron numbers at which saturation of B(E2) occurs are calculated for each isotopic chain. In particular, the calculation suggests that B( E2) saturation may occur in the 2nd half of the 82-126 major shell in erbium and ytterbium.