Associative ionization in collisions between two excited reactants

Abstract

Absolute and relative cross sections were obtained for the associative ionization (AI) reaction ${\mathrm{He}}^{*}+{\mathrm{Ne}}^{*}\to \mathrm{He}{\mathrm{Ne}}^{+}+e$ by a merging-beams technique over a range of interaction energy $W$ from 0.01 to 10 eV. The He* represents a composite of $\mathrm{He}\left(2\mathrm{}{}_{}{}^1{}_{}{}^{}S\right)$ and $\mathrm{He}\left(2\mathrm{}{}_{}{}^3{}_{}{}^{}S\right)$, and the Ne* a composite of $\mathrm{Ne}\left(3s{}_{}{}^3{}_{}{}^{}P_2^{}{}_{}{}^{}\right)$ and $\mathrm{Ne}\left(3s{}_{}{}^3{}_{}{}^{}P_0^{}{}_{}{}^{}\right)$. This study represents the first direct evidence of AI for which both reactants are excited. Studies were also made of the possible AI reaction ${\mathrm{Ne}}^{*}+{\mathrm{Ar}}^{*}\to \mathrm{Ne}{\mathrm{Ar}}^{+}+e$ from thermal energy to 10 eV.