Oscillator Strength of the Resonance Transitions of Ground-State N and O

Multiplet oscillator strengths, ${\mathrm{\Sigma g}}_L{f}_{\mathrm{LU}}$ , for the resonance triplets of N and O were determined using the line absorption method and measuring atom concentrations by chemical “titration.” For the NI triplet at 1200 Å, ${\mathrm{\Sigma g}}_L{f}_{\mathrm{LU}}\text{\hspace{0.17em}=\hspace{0.17em}0.87\hspace{0.17em}±\hspace{0.17em}0.20}$ , and excellent internal agreement was obtained among the separately measured $f_{\mathrm{LU}}$ of the three lines. A value of (3 ± 1) × 10⁻¹¹ cm³ sec⁻¹ is required for the rate constant of the N+NO→N₂+O reaction in the analysis of the data. For the OI triplet near 1300 Å, the apparent ${\mathrm{\Sigma g}}_L{f}_{\mathrm{LU}}$ increased sharply and reproducibly from 0.19 to 0.42 when the diluent gas in the discharge light source was changed from Ar to He, which indicates that excitation transfer is a major source of excitation in such Ar–O₂ resonance lamps. The larger oscillator strength obtained with He–O₂ light sources is in excellent agreement with results of lifetime measurements by other workers.