Spectrum and energy levels of triply ionized zirconium (Zr iv)

Abstract

The spectrum of Zr iv was observed with a sliding spark in the region from 440 to 2670 Å on the 10.7-m normal-and grazing-incidence spectrographs at NBS. About 30 new lines were observed. The level system (Rb i isoelectronic system, 4p6nl) was extended to include the series ns (n = 5–8), np (n = 5–7), nd (n = 4–6), nf (n = 4–6), and ng (n = 5–9). The nf series exhibits irregular fine-structure splittings and quantum defects. The ionization energy was determined from the ng series to be 277 605.8 ±1.5 cm−1 (34.4190 ± 0.0002 eV). New wavelengths were determined for the 4s24p5−4s4p6 transitions of Zr vi.