Influence of Pressure and Discharge Voltage on Spectral Intensities in a Pulsed Nitrogen Discharge Supersonic Free-Jet

Abstract

The effects of the pressure and discharge voltage on the spectral intensities of the second positive and first negative systems were studied in a pulsed nitrogen discharge supersonic free-jet. The results show that a stabilized discharge condition was reached when the vacuum chamber pressure increased to 100 Pa. Both N2(C 3 Πu) and N + 2 (B 2 Σ + u ) states were highly populated at a pressure of 100 Pa to 130 Pa. The active state N2(C 3 Πu)could be selectively populated at a low pressure of 10 Pa and a discharge voltage of 4500 V. Different populating mechanisms under the experimental conditions for N2(C 3 Πu) and N + 2 (B 2 Σ + u ) states were proposed to account for the experimental results.