Excitation of the Oi(S3) and Ni(P4) Resonance States by Electron Impact on O and N

The absolute cross sections for the excitation of the Oi(${}_{}{}^3{}_{}{}^{}S$) and Ni(${}_{}{}^4{}_{}{}^{}P$) resonance states by electron impact on atomic oxygen and nitrogen have been measured over the aeronomically important energy range from threshold to 150 eV. The peak excitation cross sections for these states were found to be 1.2 × ${10}^{-16\mathrm{}}$ and 6.2 × ${10}^{-16\mathrm{}}$ ${\mathrm{cm}}^2$, respectively. At low energies, the total Oi(${}_{}{}^3{}_{}{}^{}S$) and Ni(${}_{}{}^4{}_{}{}^{}P$) cross sections exhibited well-developed peaks near 15 and 25 eV, respectively, indicating that cascade processes probably play an important role in exciting the Oi(${}_{}{}^3{}_{}{}^{}S$) and Ni(${}_{}{}^4{}_{}{}^{}P$) states.