Formation cross sections, emission cross sections and Fano plots of translational-energy-separated excited hydrogen atoms (n = 3,4) produced in e-H2O collisions

Abstract The Doppler profiles of the Balmer α and β lines of excited hydrogen atoms produced in e-H 2 O collisions have been measured at a high optical resolution with a Fabry-Perot interferometer. Excited hydrogen atoms were separated into six groups according to their translational energies: 0–2, 2–4, 4–6, 6–8, 8–10 and 10–15 eV. Formation and emission cross sections have been determined separately for the six groups. Fano plots of the six groups indicated that contributions of optically-allowed and optically-forbidden transitions are different according to the translational energy.