Atomic and ionic states of hollow lithium

A hollow atomic system is a system where at least the more internal shell is empty. These states offer very high electronic correlation effects. They have been studied by coupling the electrons spectrometry to the synchrotron radiation at the Advanced Light Source (Berkeley) for its special brightness. Many hollow states have been thus observed and identified. Their autoionization has been characterised by the measure of the photoionisation partial cross sections. This has been completed by the anisotropy study of the electron from the hollow states non radiative relaxation. The joint use of a synchrotron radiation and a laser radiation in a two color experiment, allowed the study of also pair symmetry hollow states. The doubling excited ionic states of Li have been studied. The study of these hollow atomic states relaxation towards these ionic hollow states showed an organization of the hollow atomic states in Rydberg series. Finally the doubling hollow atomic state of lower energy (empty K and L shells), has been observed and also its energy and its lifetime have been measured. The comparison of experimental results and simulation show an excellent agreement, on one hand with the R matrix (for the partial photoionisation cross sections) and on the other hand with the Saddle-point method, for the main hollow states energies and lifetimes. (A.L.B.)