Collisional Excitation Transfer between Hydrogen Atoms II. H(2S)+H(1S) → H(1S)+H(2S)

Abstract

The cross-section for the exact resonance excitation transfer process H(2S)+H(1S)→H(1S)+H(2S), of which the interaction is a short range one, is calculated at energies of relative motion of 0.03, 0.1, 0.3, 1.0, 3.0, 5.0 and 10.0 eV by the perturbed stationary state method (PSS method). The interaction energies between hydrogen atoms are calculated by the Heitler-London method. The results are in good agreement with the results of the impact parameter method for energies of relative motion over 1.0 eV. The disagreement below 1.0 eV is due to the presence of the potential barrier in the ³ Σ _g adiabatic potential of the excited hydrogen molecule. The cross-section calculated by PSS method is 33.1π au (atomic unit) at 0.03 eV.