Nitrogen Vibrational Population Measurement in Non-Self-Sustaining DC Discharge Plasma Source

A Non-Self-Sustaining DC (NSS DC) discharge plasma source aiming for efficient nitrogen vibrational excitation by apparent reduced electric field (E/N) control has been developed. This plasma source utilizes a nanosecond pulse plasma generator and a DC power supply. The superimposed DC voltage controls the apparent E/N suitable for efficient nitrogen vibrational excitation. The temporal evolution of nitrogen vibrational distribution during/after the discharge burst is estimated by Laser Raman Spectroscopy. The vibrational excitation is enhanced with the increase of the apparent E/N, and vibrational level more than v=8 is observed. The rotational temperature is estimated with an emission from the nitrogen second positive system. Further details such as the influence of apparent E/N to generation and loss mechanism of vibrationally excited nitrogen will be discussed at the meeting.