Energies and Mean Lives of Doubly Excited Terms in Lithium

Abstract

We have observed approximately 50 new lines in the spectrum of a beam of foil-excited lithium ions (0.5–1.0-MeV beam energy) in the wavelength region 2000–11 000 Å. One line is classified as a transition in doubly excited Li ii, and the remainder are attributed to transitions between highly excited levels in Li ii, and to transitions in the doubly excited quartet and doublet systems of Li i. Six lines remain unidentified. Mean lives have been measured for some of the new Li i transitions. They help to verify the suggested identifications.