Distribution over the vibrational levels and brightness of the dissociation continuum of hydrogen molecules in a gas-discharge plasma

Based on measurements of the intensity of the Q lines of diagonal bands of the α system of Fulkher and the distribution function of the electrons over the energies, the distributions of H2 molecules over the vibrational levels of the excited d3Pi-/sub u/ and ground X1Σ+/sub g/ electronic states were investigated in a gas discharge plasma at 3 x 10-3--13-A/cm2 current densities and 1--5-Torr pressures. It was established that in a broad range of current densities in a capillary-arc discharge and in a discharge with a hollow cathode at reduced pressure predominantly the single lowest vibrational level of the ground state is populated. Systematic measurements of the spectral distribution of the brightness of the dissociation continuum of H2 and D2 molecules in the 190--500-nm region and calculations performed in the framework of a simple model of excitation confirmed and permitted explaining for the first time the empirical regularities previously observed