Knowledge Bank

Electronic spectra of $\Pi 2(i3\Pi u-C3\Pi g),N2(B3\Pi g-A3\Sigma u),CO(d3\wedge 1-a3\Pi r),CN(\wedge 2\Pi -X2\Sigma -)$ and atomic ion spectra of $He+$ and $Ar+$ have been studied in a recombination-limited hollow cathode discharge with a pulsed dye laser system over the range 490-690 nm. The time dependences of the optogalvanic signals indicate a different mechanism for the OGE in the case of ions. Extensive electronic spectra of $NH2$ have been observed at higher resolution in the range 590-640 nm with a ew ring dye laser. Additional molecular spectra observed in this region in both pure $H2$ discharges and in mixtures of $H2$ and $N2$ have not yet been identified.