Dissociative recombination of H 3 + : 10 years in retrospect

The dissociative recombination of H(3)(+) has been an intriguing problem for more than half a century. The early experiments on H(3)(+) during the first 20 years were carried out without mass analysis in decaying plasma afterglows, and thus the measured rates pertained to an uncontrolled mixture of H(3)(+) and impurity ions. When mass analysis was used, the rate coefficient was determined to be an uneventful value of about 10(-7) cm(3) s(-1), a very common rate coefficient for many molecular ions. But this was not the end of the story, not even the beginning of the end; it marked only the end of the beginning. The story I will tell in this article started about 10 years ago, when the dissociative recombination of H(3)(+) was approaching its deepest crisis. Today, owing to an extensive experimental and theoretical effort, the state of affairs has reached a historically unique level of harmony, although there still remains many things to sort out.