Oscillator strengths and radiative branching ratios in atomic Sr

Tables of radiative transition rates (A) are provided for allowed singlet and triplet transitions between Sr states below n≃11. These are obtained from a combination of R-matrix, multichannel-quantum-defect-theory (MQDT), and modified Coulomb-approximation calculations, plus branching-ratio measurements. Measurements of some spin-changing branchings and of the 4 ${}_{}{}^1{}_{}{}^{}$ ${\mathit{D}}_{2–}$5 ${}_{}{}^1{}_{}{}^{}$ ${\mathit{S}}_0$ quadrupole transition rate are also reported. Lifetime and A-value measurements from the literature are included in the tables and compared to the calculations. These and the present measurements provide the most comprehensive test to date of calculated transition probabilities for divalent atoms. The MQDT calculation achieves 0–20 % agreement with experiment in the great majority of cases tested.