Oscillator strength, transition rates and lifetimes for n=3 states in Al-like ions

Transition rates, oscillator strengths, and line strengths are calculated for the 3220 possible electric-dipole (E1) transitions between the 73 even-parity 3s3p sup 2 , 3s sup 2 3d, 3p sup 2 3d, 3d sup 2 3s and 3d sup 3 states and the 75 odd-parity 3s sup 2 3p, 3p sup 3 , 3s3p3d, and 3d sup 2 3p states in Al-like ions with the nuclear charges ranging from Z=15 to 100. Relativistic many-body perturbation theory (MBPT), including the Breit interaction, is used to evaluate retarded E1 matrix elements in length and velocity forms. The calculations start from a 1s sup 2 2s sup 2 2p sup 6 Dirac-Fock potential. First-order MBPT is used to obtain intermediate coupling coefficients and second-order MBPT is used to calculate transition matrix elements. Contributions from negative-energy states are included in the second order E1 matrix elements to ensure gauge-independence of transition amplitudes. The transition energies used in the calculation of oscillator strengths and transition rates are from second-order MBPT. Transition rates, line strengths, and oscillator strengths are compared with critically evaluated experimental values and with results from other recent calculations. As a result, we present data for the selected transition, that includes transitions between the 10 even-parity 3s3p sup 2 , 3s sup 2 3p states and the 29 odd-parity 3s sup 2 3p, 3p sup 3 , and 3s3p3d states in Al-like ions. Trends of the transition rates as functions of Z are illustrates graphically for the 220 transitions. Lifetimes of the 10 possible even-parity lower levels and the 27 possible odd-parity upper levels are given for Z=15-100.