Lifetimes of Excited Levels in Some Important Ion-molecules Part I: NH⁺, OH⁺and SH⁺

The spectra of NH + , OH + and SH + in the range 3 000-5 000 Å have been studied at 0.2-0.4 Å FWHM resolution using the High-Frequency Deflection technique. Radiative lifetimes of low-lying excited electronic states in these molecules were simultaneously measured and found to be of the magnitude of 400-1 100 ns.