Comprehensive Data for Depolarization of the Second Solar Spectrum by Isotropic Collisions with Neutral Hydrogen

Abstract

Abstract Interpretation of the second solar spectrum (SSS) requires a complete determination of the depolarizing effect due to collisions with neutral hydrogen. In this paper, we provide comprehensive collision data for simple atoms, complex atoms, and atoms with hyperfine structure. Grids of interaction potentials were computed for a large range of effective quantum numbers n* that characterize states of hypothetical simple atoms. After that, the Schrödinger equation is solved to calculate the collisional transition matrix for each value of n*. Thus, we constructed a database of collisional polarization transfer and depolarization rates of all p-, d-, and f-states of simple atoms. The obtained results are fitted to deduce 48 variation laws, leading to the determination of all depolarization and polarization transfer rates of solar simple atoms. These laws are general and can be applied for any simple atom. We demonstrate how these laws can be used to efficiently obtain the collision rates associated with complex atoms, as well as with atoms with hyperfine structure. We show how the reader may use the variation laws to reproduce all new (de)polarization rates of this paper, as well as all rates of our previous papers published since 2003. Accuracy of our variation laws is discussed. Our analytical laws can be easily implemented in the numerical models developed to simulate the formation of the SSS.