Theoretical lifetimes of the Al2S,2

Abstract

The natural lifetimes of the aluminum 3s nl, n =3-12, 1=0-3, have been calculated using wave functions that were obtained by direct numerical integration of the Schrodinger equation with a central potential to describe the ionic core and experimental term energies as input. The strong perturbation of the 3s nd D series by the yet to be experimentally identified 3s3p D perturber has been explicitly treated semiempirically by using experimental mixing coefficients. Inclusion of at least this perturbation is essential for good agreement with experiment. The effects of blackbody radiation are also explicitly included and have a dramatic effect on the lifetimes of the np states. Core-polarization effects are also included in the transition matrix elements.PACS number(s): 32.70.Fw, 31.50.+wThe excited states of Al, and especially the members of

Commission 14: Atomic and Molecular Data (Donnees Atomiques Et Moleculaires)

“…120 The quartet and sextet states of FeH have been studied theoretically by Langhoff and Bauschlicher. 121 The calculations are entirely consistent with the earlier observations of the near-infrared system by Phillips and Davis, but the spectroscopic designation should be F 4 A-X 4 A. Theoretical studies of FeH + have also been presented by Langhoff and colleagues.…”

Microwave spectroscopy of Al I atoms in Rydberg states: D and G terms

“…The natural radiative lifetimes of the Rydberg states are proportional to n 3 . Scaling from the values given by Theodosiou [19] we obtain τ nD = 0.73-5.5 µs for n = 23-45 and τ nF = 8-60 µs for n = 22-43. For nD states with n 32 radiative decay thus contributes less than 1 MHz to the resonance linewidth, and lifetime broadening of F and G levels is negligible.…”

Absolute transition probabilities of Al I and Al II spectral lines and intensity ratios within multiplets

“…These values agree well with experimental data. There is a difference for (3d, 4d) excited states with theoretical data of C. E. Theodosiou (Theodosiou 1992), since in the latter paper the electron configuration interaction effect (CI) had not been taken into account. This effect originates from the influence of all nd series by the 3s3p 2 2 D level, but mainly of the low lying 3d, 4d levels.…”

“…Many measurements were undertaken of 4s and 3d lifetimes, and s, p, d level series were experimentally covered in a wide range: ns for n = 4−10 (Jönsson & Lundberg 1983;Buurman et al 1986), np for n = 4−12 (Buurman et al 1986;Jönsson et al 1984), nd for n = 3−13 (Jönsson & Lundberg 1983;Buurman et al 1986;Davidson et al 1990). For the nf levels only theoretical values exist (Theodosiou 1992).…”