Electron impact excitation of the G 1Σ+/sub g/ state of H2

The optical excitation function for the G 1Σ+/sub g/ → B 1Σ+/sub u/ transition of the H2 spectrum has been determined for the electron impact energies in the range 0-500 eV and at H2 gas pressures < or = 30 mtorr. Measurements of the absolute emission cross section for the lambda = 4634 A [G → B(0, 0)P1,R2,R3] vibration-rotational line blend have been carried out at 200 eV incident electron energy. Measurements of the G 1Σ+/sub g/(v' = 0) state radiative lifetime have also been carried out and yield a single-mode decay, with a lifetime of approx. 30 ns. Both dc intensity and time-solved lifetime measurements are observed to be independent of H2 gas pressure and electron beam current over the regions approx. 2 to 50 mtorr and 5 μA to 1 mA, respectively