The (2.0) vibrational band of the A2Πu-X2Σ+g system of the N+2 ion has been observed by near-infrared diode laser absorption spectroscopy. A signal-to-noise ratio greater than 50 at a time constant of 100 msec was obtained using the hollow cathode discharge modulation technique. In total, 108 lines were identified as belonging to the (2,0) band of the N+2A-X system. The observed wavenumbers were least-squares fitted, yielding precise spectroscopic constants, the band origin T20 and the spin-orbit coupling constant A2 being 12 732.83583(31) and -74.63529(54) cm-1, respectively, where the uncertainties given in the parentheses correspond to one standard deviation. The Dunham coefficients revised by combination of the present result and previous results of high-resolution studies are also presented.
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics
- Physical and Theoretical Chemistry