Characterization of afterglow kinetics at atmospheric pressures by emission spectroscopy. I: reactions of neon ions with N-2

The afterglow of a 1 kA, 10 ns duration discharge in neon at 1-4 bar pressu re containing up to 10 mbar of reactant admixture N-2 was studied by time-r esolved emission spectroscopy. Destruction rates of neon ions have been exp erimentally determined from the selectively excited fluorescence of N-2(+) emitted as the result of charge transfer. Reasonable agreement with previou sly reported results was obtained over the smaller range of nitrogen pressu res (below 0.8 mbar) used in those studies. Data obtained at reactant press ures higher than about 1.2 mbar were consistent with a kinetic model in whi ch vibrationally excited Ne-2(+) ions play an important role. The slow coll isional relaxation of these ions (rate coefficient 3.7 x 10(-13) cm(3) s(-1 )) would limit the rate of Ne+ to Ne-2(+) conversion at neon pressures high er than about 0.2 bar.