Émission de rayonnement Lyman α dans les collisions H2 + H*(2s) aux énergies thermiques

Abstract

The study made in Can. J. Phys. 68, 206 (1990) of the thermal-energy collision between H2 and metastable H*(2s), which could lead to the emission of Lyman α radiation, is reconsidered to take into account possible polarization effects. The total wave function of the system is expanded in terms of the molecular states of the intermediate complex [Formula: see text], which constitute the minimal basis of the four adiabatic states dissociating into H2 + H* (n = 2) where they are normally degenerate in energy. The results of the calculation show the existence, between three of those states, of average values of the separation distance R ([Formula: see text] atomic units) of long-range [Formula: see text] electronic interactions which depend on the geometric form of the [Formula: see text] molecule. From the molecular data the hypothesis of no longer considering H2 with H*(2s) as a rigid rotator is postulated and justified, after a purely quantum mechanical treatment of the radial equations, the mean ratio of the (oscillating) polarization angular differential cross sections to the elastic ones is found important [Formula: see text]. The inelastic phenomena are anticipated to be more marked in the ortho than in the para hydrogen at a low collision energy (75 meV).[Journal translation]