EXCITATION OF FINE-STRUCTURE TRANSITIONS IN O BY H-2

Cross-sections σ(J→J) have been computed for the excitation of fine structure transitions in O(3PJ) by para-H2 in its rotational ground state (j = 0). The potentials were derived as modified fits to the SCF and dispersion energies of interaction for O-He. Owing to the larger polarizability of H2, compared with He, the cross-sections for excitation by H2 are larger at low collision energies than for excitation by He. The propensities of the cross-sections are the same for both perturbers, with σ(0→1) being much smaller than σ(0 → 2) or σ(1→ 2). © Royal Astronomical Society • Provided by the NASA Astrophysics Data System.