Wavelength measurements in the quartet term system of doubly excited OVI and FVII

Abstract

In the emission spectra of beam-foil excited oxygen and fluorine, it has been possible to assign lines to the quartet term systems of doubly excited three electron ions. A comparison with known spectra of singly excited four-electron systems turned out to be useful for line identification. The measured wavelengths are compared to theoretical predictions.

High‐lying core‐excited quartet states in Li‐like N4+ and F6+ ions

“…With the same method, the transitions in core-excited quartet states for C 3þ , N 4þ , O 5þ , F 6þ ions were also investigated by Martinson et al [6] and Blanke et al [3,4]. Later, Bouchama et al [2] observed the doubly excited quartet systems of N 4þ ions by charge exchange of highly charged ions with gaseous targets.…”

“…Livingston and Berry [5] reported the fine structure and transition wavelengths of coreexcited states 4 P o and 4 P in Li-like ions (Z ¼ 6-9) through the beam-foil spectroscopy. With the same method, the transitions in core-excited quartet states for C 3þ , N 4þ , O 5þ , F 6þ ions were also investigated by Martinson et al [6] and Blanke et al [3,4].…”

“…Using Rayleigh-Ritz method, Holøien and Geltman [14] first studied the quartet states of Li-like ions (Z ¼ 2-10). Cheng et al [11] explored the fine structure and transition wavelengths of the 1s2s2p 4 …”

“…Later, Larsson et al [18] calculated the energies of lowest core-excited quartet states 4 S (m ¼ 1-3) and 4 P o (m ¼ 1-3) (Z ¼ 3-10) for Li-like ions by the Hylleraas method. Using the Dirac-Hartree-Slater (DHS wave function) method, Chen et al [9] identified the transition 1s2s2p 4 P o À 1s2p2p 4 P for the Li-like ions (6 Z 30).…”

“…o and 1s2p2p 4 P of Li-like ions with the method of multiconfiguration Hartree-Fock method. Later, Larsson et al [18] calculated the energies of lowest core-excited quartet states 4 S (m ¼ 1-3) and 4 P o (m ¼ 1-3) (Z ¼ 3-10) for Li-like ions by the Hylleraas method.…”