Electron impact excitation of the G¹∑g+ state of H_2†

Abstract

The optical excitation function for the G¹∑g+→B¹∑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 ≤ 30 mtorr. Measurements of the absolute emission cross section for the λ = 4634 Å [G → B(0, 0) P1,R2,R3] vibration-rotational line blend have been carried out at 200 eV incident electron energy. Measurements of the G¹∑g+(ν′=0) state radiative lifetime have also been carried out and yield a single-mode decay, with a lifetime of ∼ 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 ∼ 2 to 50 mtorr and 5 μA to 1 mA, respectively.