Dissociative recombination of theCO2+dication

Abstract

Dissociative recombination of a doubly charged molecular ion ${\mathrm{CO}}^{2+}$ has been studied, using a heavy-ion storage ring. There are two final channels of this reaction $({\mathrm{C}\mathrm{}+\mathrm{}\mathrm{O}}^{+}$ and ${\mathrm{O}\mathrm{}+\mathrm{}\mathrm{C}}^{+})$ that were found to be of about equal strength up to an energy of about 2 eV. The total recombination cross section (yielding C or O) is found to be $\ensuremath{\sigma}=[2.2/E(\mathrm{eV})]\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}16}{\mathrm{cm}}^{2}$ for $El~1$ eV, where E is the electron energy. This indicates that the recombination is of the direct type with a curve crossing between the initial state and some repulsive curve of the singly charged ion. Within an accuracy of a factor of 2 we obtain a total recombination rate coefficient $\ensuremath{\alpha}=0.9\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}7}{\mathrm{cm}}^{3}{\mathrm{s}}^{\ensuremath{-}1}$ at $T=300$ K that is comparable to that of ${\mathrm{CO}}^{+}.$