Dissociative Ionization of N2 and N2O by Rare-Gas Ion Impact

Abstract

Cross sections for the reactions $$\begin{array}{cc}{\mathrm{Ne}}^{+}+{\mathrm{N}}_2\to {\mathrm{N}}^{+}+\mathrm{N}+\mathrm{Ne},& {\mathrm{Kr}}^{+}+{\mathrm{N}}_2\mathrm{O}\to {\mathrm{O}}^{+}+{\mathrm{N}}_2+\mathrm{Kr},\\ {\mathrm{Ar}}^{+}+{\mathrm{N}}_2\to {\mathrm{N}}^{+}+\mathrm{N}+\mathrm{Ar},& {\mathrm{Kr}}^{+}+{\mathrm{N}}_2\mathrm{O}\to \mathrm{N}+{\mathrm{NO}}^{+}+\mathrm{Kr},\end{array}$$ are measured as functions of primary ion kinetic energy. All of these reactions exhibit thresholds, and a semiempirical formula is fitted to the data near to the threshold energies. Despite the isoelectronic character of the products of ${\mathrm{Kr}}^{+}+{\mathrm{N}}_2\mathrm{O}\to {\mathrm{O}}^{+}+{\mathrm{N}}_2+\mathrm{Kr}$ and ${\mathrm{Kr}}^{+}+{\mathrm{N}}_2\mathrm{O}\to \mathrm{N}+{\mathrm{NO}}^{+}+\mathrm{Kr}$ , their behavior differs in that the former reaction proceeds by the energetically most favorable channel while the latter does not; the reaction ${\mathrm{Kr}}^{+}+{\mathrm{N}}_2\mathrm{O}\to \mathrm{N}+{\mathrm{NO}}^{+}+\mathrm{Kr}$ is energetically allowed for all primary ion kinetic energies but appears not to proceed below kinetic energies of about 2.4 eV in the center‐of‐mass coordinate system. The cross sections of reactions involving only atomic products do not exhibit any striking, qualitative differences from those cross sections involving molecular products.