Abstract
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.