A Novel Merged-Beam Apparatus for Studying Anion-Neutral Reactions
Abstract
We have developed a novel apparatus at the Columbia Astrophysics Laboratory to study anion-neutral reactions. Beginning with an anion beam, we use photodetachment to generate a self-merged, anion- neutral beams arrangement. Laboratory beam energies are in the keV range. Because the beams run co-linear, center-of-mass energies from the meV to keV range are achievable. Our proof-of-principle measurement is the associative detachment (AD) reaction H^- + H ->H2+ e^-. Published values for this process differ by almost an order of magnitude. With theory and experiment unable to reach a consistent description for this fundamental molecular formation reaction, it raises questions of how can we expect to do better for anion-neutral reactions involving more complicated systems? Measurements using our novel apparatus will help to resolve this fundamental issue in physics and chemistry. We observe the AD reaction by detecting fast H2^+ ions formed through ionizing collisions of the AD-generated H2 with He inside a gas cell. Here we present the current status of the project and discuss our future plans.
- Publication:
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APS Division of Atomic, Molecular and Optical Physics Meeting Abstracts
- Pub Date:
- May 2009
- Bibcode:
- 2009APS..DMP.E1022M