Spontaneous transition rates for electric dipole (E1), magnetic dipole (M1), electric quadrupole (E2) and magnetic quadrupole (M2) transitions for He-like calcium and sulfur ions

The spontaneous decay rates for the electric dipole (El), electric quadrupole (E2) magnetic dipole (M1) and magnetic quadrupole (M2) transitions between all of the 1s(2), 1s2l and 1s3l states have been obtained for helium-like calcium and sulfur ions. To assess the accuracy of the calculations, the transition probabilities were calculated using two sets of configuration interaction wave-functions. One set of wave-functions was generated using the fully relativistic GRASP code and the other wash obtained using CIV3, in which relativistic effects are introduced using the Breit-Pauli approximation. The transition rates, A values, oscillator strengths and line strengths from our two calculations are found to be similar and to compare very well with other recent results for Deltan = I or 2 transitions. For Deltan = 0 transitions the agreement is much less good; this is mainly due to differences in the calculated excitation energies.