Relativistic fine-structure oscillator strengths for Li-like ions

Relativistic configuration interaction results on the weighted oscillator strengths are presented for the K$\beta$ satellite x rays from $1s2s3p-1s^{2}2s$ transitions in Li-like ions with $14⩽Z⩽54$. The calculations are carried out in the active space approximation using multiconfiguration Dirac-Fock wave functions with the inclusion of the finite nuclear size effect, the Breit interaction, and quantum electrodynamic corrections. The resulting x-ray wavelengths and rates are compared with other available data. An attempt is also made to analyze the irregularities in the fine-structure energy levels and x-ray rates due to configuration mixing together with the Breit interaction.

Figure 1

Contribution from large configuration interactions to the allowed transition rates. The curves a, b, c, and d represent transitions to $1s^{2}2s{}^2{S}_{1/2}$ state from $1s2s({}^3{S}_1)3p{}^2{P}_{1/2}$, $1s2s({}^3{S}_1)3p{}^2{P}_{3/2}$, $1s2s({}^1{S}_0)3p{}^2{P}_{1/2}$ and $1s2s({}^1{S}_0)3p{}^2{P}_{3/2}$ states, respectively.

Figure 2

Percentage contribution from Breit interaction to the transition rates. The transitions are from initial $J$ $=$ 1/2 to final $J$ $=$ 1/2 states. The curves a, b, and c represent transitions from $1s2s({}^3{S}_1)3p{}^2{P}_{1/2}$, $1s2s({}^1{S}_0)3p{}^2{P}_{1/2}$, and $1s2s({}^3{S}_1)3p{}^4{P}_{1/2}$ states, respectively.

Figure 3

Percentage contribution from the Breit interaction to the transition rates. The transitions are from $J$ $=$ 3/2 states and the legends are the same as in Fig. 2.

Figure 4

Weighted oscillator strengths (gf) in powers of ${10}^{-2}$ as a function of $Z$. The curves a, b, c, d, and e correspond to the allowed $1s2s({}^3{S}_1)3p{}^2{P}_{1/2}$, $1s2s({}^1{S}_0)3p{}^2{P}_{1/2}$, $1s2s({}^3{S}_1)3p{}^2{P}_{3/2}$, $1s2s({}^1{S}_0)3p{}^2{P}_{3/2}$, and the forbidden $1s2s({}^3{S}_1)3p{}^4{P}_{3/2}$ transitions to $1s^{2}2s({}^2{S}_{1/2})$ state, respectively.