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

摘要

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(C3∏u) and N2+(B2∑u+) states were highly populated at a pressure of 100 Pa to 130 Pa. The active state N2(C3∏u)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(C3∏u) and N2+(B2∑u+) states were proposed to account for the experimental results.