4s^24p^4–4s4p^5 transitions in Zr vii, Nb viii, and Mo ix*

Abstract

Spectra of ionized Zr, Nb, and Mo have been observed in sliding spark discharges at peak currents up to 4000 A on the 10.7 m normal and grazing incidence spectrographs at NBS. From these observations the group of 4s24p4–4s4p5 transitions in Zr vii, Nb viii, and Mo ix have been identified and measured. The energy parameters obtained from least-squares fits to the resultant energy levels are compared with Hartree-Fock calculations.