Paramagnetic-Resonance Spectrum of Metastable (D2) Atomic Nitrogen

Abstract

The paramagnetic-resonance spectrum of free metastable (${}_{}{}^2{}_{}{}^{}D$) nitrogen atoms has been observed in the flowing products of an electric discharge in nitrogen-helium gas mixtures. An analysis of the Zeeman effect and hyperfine structure yields the following values for the atomic $g$ factors and radial integrals: $g_J\left({}_{}{}^2{}_{}{}^{}D_{\frac{5}{2}}^{}{}_{}{}^{}\right)=1.20036\mathrm{}\pm 0.00001$; $g_J\left({}_{}{}^2{}_{}{}^{}D_{\frac{3}{2}}^{}{}_{}{}^{}\right)=0.79949\mathrm{}\pm 0.00002$; $〈{r_l}^{-3\mathrm{}}〉=(20.21\mathrm{}\pm 0.02)\times {10}^{24}$ ${\mathrm{cm}}^{-3\mathrm{}}$; $〈{r_s}^{-3\mathrm{}}〉=(22.22\mathrm{}\pm 0.02)\times {10}^{24}$ ${\mathrm{cm}}^{-3\mathrm{}}$. The ${}_{}{}^2{}_{}{}^{}D$ fine-structure separation is found to be -8.69±0.02 ${\mathrm{cm}}^{-1\mathrm{}}$. Evidence is found of a small electric-quadrupole hyperfine-structure interaction.