Rotational-Resolved Fluorescence Spectrometry of N2 - The Effects of Predissociation and Temperature

An ultrahigh resolution (0.004 nm) spectrometer has been utilized to study the extreme ultraviolet fluorescence of the c4'(0)-X, b'(1)-X, and b(1)-X transitions of N2 in the vicinity of 95.8 and 98.5 nm, respectively. The new experimental apparatus allows us to obtain partially rotational-resolved fluorescence excitation spectra using a synchrotron radiation source. We have carried out experiments at 295 K and 93 K, and in some cases at 120 K and 150 K. In addition, we have observed a new Rydberg state in the well known region of the Codling series between 50 and 55 nm. This is the first time that a Rydberg series of N2 has been observed in such high energy regime. The detailed results will be presented. The present results may be useful in the explanation of the important N2 features in the dayglow of the Earth. The low temperature data may be directly applicable to the characterization of the N2 emissions in the atmospheres of Titan and Pluto. This research is based on work supported by the NSF Planetary Astronomy Program under Grant AST-0906158.