Dissociative recombination of the CO2+ dication

Dissociative recombination of a doubly charged molecular ion CO2+ has been studied, using a heavy-ion storage ring. There are two final channels of this reaction (C + O+ and O + 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 sigma = [2.2/E(eV)] X 10(-16) cm(2) for E less than or equal to 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 alpha = 0.9 X 10(-7) cm(3) s(-1) at T= 300 K that is comparable to that of CO+. [S1050-2947(99)51011-1].