Electron impact excitation of H2 (D2). Resonance phenomena associated with the X 2Σu+ and B 2Σg+ states of H2- in the 10 eV region

Quantitative results have been obtained for vibrational excitation of both H2 and D2 by electron impact at 10 eV. A strong isotope effect is observed for the lowest levels where the X 2 Sigma u+ resonance produces the main contribution. The B 2 Sigma g+ resonance is only observed weakly in the high vibrational level cross sections. Vibrational excitation was also observed at 5 eV where only the X 2 Sigma u+ resonance is present. The near-threshold cross section of the b 3 Sigma u+ state was determined with the aim of observing the B 2 Sigma g+ resonance in this channel. No such contribution was detected, the cross section appeared to be dominated by direct scattering.