The N2 and NI Emissions in the VUV Region: A Low Temperature Study

Dispersed fluorescence spectra (DFS) and fluorescence excitation spectra (FES) produced through photoexcitation of N2 using synchrotron radiation in the extreme ultraviolet and vacuum ultraviolet regions have been obtained. An ultrahigh resolution (0.004 nm) spectrometer has been utilized to obtain a rotationally resolved FES experiment in spectral region between 80 and 100 nm. In the DFS experiments we have employed a 0.5-m and a 0.2-m spectrometer coupled with a position-sensitive-array detector to study the fluorescence spectra. Furthermore, we have also measured the fluorescence cross sections of several NI lines produced through photoexcitation of N2 at room and low temperature conditions. We are currently carrying out the above N2 experiments at temperatures as low as 77 K so that the data can be applicable to the characterization of the N2 emissions in the atmospheres of Titan and Pluto. Detailed results will be presented. This research is based on work supported by NSF grant AST-0906158.