Wavelengths, classifications, and ionization energies in the isoelectronic sequences from Yb ii and Yb iii through Bi xv and Bi xvi†

Abstract

Spectral observations are reported for transitions to the ground term and first excited term of the one-electron configurations in the 4f145p6nl isoelectronic sequence from Yb ii through Bi xv. Resonance lines are reported for the isoelectronic sequence Yb iii through Bi xvi in which the ground state is 4f145p61S0 and the upper levels are the J = 1 levels of the 4f135p6nd, 4f145p5nd, and 4f145p5ns configurations. The wavelengths fall in the range 70–3700 A. The spectra were produced by means of sliding and triggered spark discharges and photographed with 10.7 m normal and grazing incidence spectrographs. The data in the Yb iii sequence demonstrate the crossing of binding energies of the 4f and 5p shells at W vii. Rydberg series terms were found in a sufficient number of cases to provide extrapolation curves through Bi xv and Bi xvi. These data enabled us to calculate ionization energies for each of these ions with an uncertainty of ~1% or better.