Relativistic many-body calculations of electric-dipole lifetimes, transition rates, and oscillator strengths for n = 3 states in Al-like ions

Transition rates, oscillator strengths, and line strengths are calculated for electric-dipole(E1) transitions between even-parity 3s3p, 3s3d, 3p3d, 3d3s and 3d states and odd-parity3s3p, 3p, 3s3p3d, and 3d3p states in Al-like ions with the nuclear charges ranging fromZ = 15 to 100. Relativistic many-body perturbation theory (MBPT), including the Breitinteraction, is used to evaluate retarded E1 matrix elements in length and velocity forms. Thecalculations start from a 1s2s2p Dirac-Fock potential. First-order MBPT is used to obtainintermediate coupling coefficients and second-order MBPT is used to calculate transition matrixelements. Contributions from negative-energy states are included in the second-order E1 matrixelements to ensure gauge-independence of transition amplitudes. Transition energies used in thecalculation of oscillator strengths and transition rates are from second-order MBPT. Transitionrates, line strengths, and oscillator strengths are compared with critically evaluated experimentalvalues and with results from other recent calculations. We present data for selected transitionsbetween 10 of the possible 73 even-parity3s3p, 3s3d states and 29 of the possible 75 odd-parity3s3p, 3p, and 3s3p3d states in Al-like ions. Trends of the transition rates as function of Z areillustrated graphically for 220 of the 3220 possible transitions. Lifetimes of the 10 even-paritylower levels and the 27 odd-parity upper levels are given for Z = 15–100.