Fluorescence Produced Through Photoexcitation of Atmospheric N2 and O2

This is a summary report of the fluorescence project conducted at USC. Fluorescence spectra and fluorescence excitation spectra produced through photoexcitation of atmospheric N2 and O2 have been obtained using synchrotron radiation in the extreme ultraviolet region. In case of need a high resolution spectroscopy beamline has been utilized to provide extreme ultraviolet photons with a bandwidth (fwhm) of 0.004 nm in the spectral region between 45 and 100 nm so that high resolution fluorescence excitation spectra can be studied in great details. We have employed a 0.5-m spectrometer coupled with a position-sensitive-array detector to take images of fluorescence spectra from 50 to160 nm region. Both atomic and molecular emissions of N, O, and N2 have been investigated at room temperature and at temperatures as low as 93 K. The goal is to provide data that can be applicable to the characterization of the N2 emissions in the atmospheres of Earth, Titan and Pluto, and possibly the OI and OII dayglow emissions in the lower thermosphere of Earth. Detailed results will be presented. This research is based on work supported by NSF grant AST-0906158.