A Novel Merged-Beams Apparatus for Studying Anion-Neutral Reactions

POSTER

Abstract

We are developing 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 will be achievable. Our proof-of-principle measurement is the associative detachment (AD) reaction ${\rm H}^- + {\rm H} \to {\rm H}_2 + {\rm e}^-$. Published values for this process differ by over a factor of 5. Measurements using our novel apparatus will help to resolve this fundamental issue in physics and chemistry. We will observe the AD reaction by detecting fast H$_2^+$ ions formed through ionizing collisions of the AD-generated H$_2$ with the background gas in the vacuum chamber. Here we present the current status of the project and discuss our future plans.

*This work is supported in part by the NSF Chemistry Research Instrumentation and Facilities: Instrument Development (CRIF:ID) Program.

Authors

  • Daniel W. Savin

    • Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027

  • H. Bruhns

  • H. Kreckel

  • M. Lestinsky

  • W. Mitthumsiri

  • M. Schnell

  • B. Seredyuk

    • Columbia Astrophysics Laboratory

  • M.E. Bannister

  • C.C. Havener

    • Oak Ridge National Lab

  • A. Dorn

    • Max Planck Institute for Nuclear Physics

  • O. Heber

  • M.L. Rappaport

    • Weizmann Institute of Science

  • A.M. Covington

    • University of Nevada at Reno