Cold Chemistry with Water

In cold, dilute gases such as the interstellar medium (ISM), the chemical reactions are dominated by ionic species since their net charge allows them to polarize and "capture" nearby neutrals for reactions.  Tiangang and Gary have recetly released the first results from their "ISM in a bottle" experiment, where they controlled the reactions of laser-cooled Be+ ions with neutral water molecules.  Surprisingly, despite the fact that this reaction is exothermic and allowed even at zero temperature, the reaction rate is suppressed compared to capture theory, an effect that our theory collaboratrs show is due to a bottleneck in the reaction pathway called a submerged barrier.  Exotic effects of this type will be the target of study in this apparatus for the next phase of work.