Collisional depolarization and transfer rates of spectral lines by atomic hydrogen. IV. Application to ionised atoms

The semi-classical theory of collisional depolarization of spectral lines that we have applied to neutral atoms in previous papers is extended to spectral lines of singly ionised atoms. In order to validate our general theory, we compare our results to quantum chemistry calculations obtained for the particular cases of the 3d ²D and 4p ²P states of the CaII ion. As a demonstration of the universality of our theory and the easiness of its application, we calculate depolarization and polarization transfer rates for the 5p ²P state of the SrII ion. Analytical expressions of all rates as a function of local temperature are given. Our results for the CaII ion are compared to recent quantum chemistry calculations. A discussion of our results is presented.