Fano plots for the slow and fast groups of excited hydrogen atoms produced in e-H2 collisions

Abstract Excited hydrogen atoms ( n = 3, 4, 5) produced in the electron-impact dissociation of hydrogen molecules have two groups; slow and fast. The Balmer α, β, and γ lines, obtained at high optical resolution, have been separated into two groups and the emission cross sections of each group have been determined for electron energies of 30–2000 eV. Their Fano plots indicate that the slow group is produced through optically allowed transitions and that the fast group is produced through optically forbidden transitions.