Absorption or emission during a collision : a test case H+ 2

Abstract

The close coupled theory of scattering in a radiation field may be used to describe absorption or emission processes occurring during a collision. Using a semi-classical description of the collision we study the evolution of the collisional complex. The case of atomic hydrogen perturbed by protons is particularly interesting since the exact solution of the dynamical problem is known for a large domain of internuclear distances. In the particular case of the Ly α line we determine the characteristic time of the absorption or the emission. The « impact » and « quasistatic » limits are then analysed