Time-resolved Fourier transform infrared emission spectroscopy of He2 produced by a pulsed discharge

Time-resolved Fourier transform spectroscopy was applied to the study of He-2 infrared emission produced by a pulsed discharge in pure He. In the 1800-8000 cm(-1) region, new electronic bands have been observed in addition to the previously reported transitions. From the observed time profiles of emission spectra, Rydberg states with higher energy than the b(3)Pi state produced efficiently in afterglow plasma have been identified. Rotational assignments and a least-squares analysis for the h(3)Sigma(u)(+)-g(3)Sigma(g)(+) and g(3)Sigma(g)(+)-d(3)Sigma(u)(+) bands in the 3200 cm(-1) region were carried out to determine the molecular constants. A new band from an unidentified g U state to the d(3)Sigma(u)(+) state has been observed in the 6300 cm(-1) region with irregular P- and R-branch intensities. (C) 2003 Elsevier B.V. All rights reserved.