Lifetimes and energy levels for some core-excited quartet states in Na i

The core-excited quartet spectrum of Na i produced by beam-foil excitation has been studied in the 3300–5500-Å region. Sixteen new lines, representing transitions between the 2$p^5$3s3p, 2$p^5$3s3d, and 2$p^5$3s4s configurations, are reported, together with the lifetimes for 12 of the levels belonging to the 2$p^5$3s3d and 2$p^5$3s4s configurations. Some of the lifetimes deviate considerably from recently published values [L. Engström, L. Young, L. P. Sommerville, and H. Berry, Phys. Rev. A 32, 1468 (1985)], including the lifetimes of the 2$p^5$3s3d ${}_{}{}^4{}_{}{}^{}\mathrm{D}_{3/2}^{}{}_{}{}^{}$ and ${}_{}{}^4{}_{}{}^{}\mathrm{F}_{5/2}^{}{}_{}{}^{}$ levels, which have both been suggested for use in an extreme ultraviolet (xuv) laser. The experimental data for fine-structure splittings and lifetimes are in good agreement with multiconfiguration Hartree-Fock calculations.