摘要

In the abundance spectrum of r-process nuclei the most prominent features are the peaks that form when the r-process flow passes through the closed neutron shells. However, there are also other features in the abundance spectrum that cannot be explained by shell effects; for example, the peak in the region of the rare-earth nuclei around mass A = 160. It has been argued that this peak is related to the deformation maximum of the neutron-rich isotopes. In recent years, both experimental and theoretical work has been carried out to study the deformation of neutron-rich rare-earth nuclei and to search for the point of maximum deformation. This work has focused on the nuclei around Dy-170 with the aim of understanding the evolution of collectivity in the neutron shell with 82 %26lt; N %26lt; 126. These investigations will be discussed in terms of the Harris parameters of the variable moment of inertia model. Finally, we will discuss the possibility of reaching further into the neutron-rich rare-earth region in the future at the new experimental facilities using radioactive beams.

  • 出版日期2012-10