Analysis of the Spectrum of Doubly Ionized Rubidium (Rb iii)

Abstract

The spectrum of Rb iii has been observed in a sliding-spark discharge with the NBS 10.7-m normal-incidence vacuum spectrograph, and in an electrodeless discharge in a magnetic field with the NBS 10.7-m Eagle spectrograph in air. The analysis has yielded most of the levels of the 4p44d, 4p45s, and 4p45p configurations. The 4p45p levels and the 4s24p44d+4s24p45s+4s4p6 group of levels have been theoretically interpreted, with configuration interaction included. The energy parameters determined from a least-squares fit to the observed level values are compared with Hartree–Fock calculations. The ionization energy is estimated to be 39.0±0.3 eV.