ELECTRON-IMPACT DIRECT DISSOCIATIVE-IONIZATION CROSS-SECTIONS FROM VIBRATIONALLY EXCITED H-2-MOLECULES AND TRANSLATIONAL ENERGY-DISTRIBUTION FUNCTIONS OF PROTONS

Dissociative-ionization cross sections for the processes e+H2(ν)→2e+H2+(2Σg+, 2Σu+)→2e+H++H have been calculated by using the Gryzinski theory in combination with the Franck-Condon density for different vibrational levels of H2. The results show that the cross sections involving the completely repulsive state 2Σu+ of H2+ monotonically increase with increasing vibrational quantum number ν, while those involving the repulsive part of the bound 2Σg+ state of H2+ increase up to ν=4, presenting an opposite behaviour from ν=5 on. These results have been utilized to calculate the translational energy distribution function (TEDF) of protons. The presence of vibrationally excited H2 molecules strongly affects TEDF by filling the gap between "cold" and "hot" protons. © 1990.