Study of the Temperature Dependence of Electron-Ion Recombination in Nitrogen

The temperature dependence of the afterglow decay of electrons and ions from microwave discharges in nitrogen-neon gas mixtures has been studied using combined microwave and mass-spectrometric techniques. Under conditions where $\mathrm{N}_2^{}{}_{}{}^{+}$ is the only significant afterglow ion species, i.e., at nitrogen pressures less than ${10}^{-2\mathrm{}}$ Torr, and for neon pressures in the range 15 to 40 Torr, the afterglow is controlled by the recombination of $\mathrm{N}_2^{}{}_{}{}^{+}$ ions and electrons. Over the temperature range studied, 205 to 480°K, the recombination coefficients exhibit no significant temperature dependence and can be represented by the constant value $\alpha \left(\mathrm{N}_2^{}{}_{}{}^{+}\right)=(2.7\mathrm{}\pm 0.3)\times {10}^{-7\mathrm{}}$ ${\mathrm{cm}}^3$/sec. At any given temperature the results show no systematic dependence on the nitrogen or neon gas pressure over the ranges indicated. Temporal mass analysis indicates similar decay rates for the $\mathrm{N}_2^{}{}_{}{}^{+}$ ions and for the electrons over the major portion of the afterglow.