Measurement of the Branching Ratio for the Dissociative Recombination of H3+ + e

The dissociative recombination of ${\mathrm{H}}_{3}^{+}$ with electrons can have two exit channels, namely $e$+ ${\mathrm{H}}_{3}^{+}$\ensuremath{\rightarrow}H + H + H (channel I), and $e$+ ${\mathrm{H}}_{3}^{+}$\ensuremath{\rightarrow}${\mathrm{H}}_{2}$ + H (channel II). A new technique has been developed which has been used to determine the relative contributions of channels I and II to the overall recombination process. Over the energy range from 0.01 to 0.05 eV it has been found that channel I dominates.