Tensorial depolarization of alkali atoms by isotropic collisions with neutral hydrogen
1 Institut d’Astrophysique Spatiale, CNRS-Université Paris-Sud 11, 91405 Orsay Cedex, France
2 Sousse University, LabEM (LR11ES34), ESSTHS, Lamine Abbassi street, 4011 H. Sousse, Tunisia
Received: 1 June 2012
Accepted: 23 July 2012
We consider the problem of isotropic collisions between an alkali atom and neutral hydrogen. We calculate the collisional tensorial components of general p and s-states, characterized by their effective principal quantum number n∗. We find that the behaviour of the tensorial components obey simple power laws allowing quick calculations of the depolarizing collisional rates. As a possible application, our results should allow a rigorous treatment of the atomic polarization profiles of the D1−D2 lines of alkali atoms. Finally, we notice that important problems remain unresolved, such as the role of collisions in the Paschen-Back conditions.
Key words: scattering / polarization / atomic processes / Sun: atmosphere / line: formation
© ESO, 2012