Work

Beating Tunnel Vision: Near-Surface Velocity-Map Imaging

Year: 2026

Type: article

Abstract: We demonstrate a new methodology for applying velocity-map imaging (VMI) to the study of gas-surface dynamics that allows direct imaging of the scattering plane. By bringing the surface near to the ionization laser inside the VMI electrodes, we demonstrate a route to overcoming "tunnel vision", a term used to describe the limited angular acceptance of measurements taken at too great distance from where the gas-surface interaction takes place. Using a molecular beam of NO molecules colliding with a surface of highly oriented pyrolytic graphite as an exemplar system, we show the correlation between the laser-surface distance and the accessible scattering angular range. We demonstrate the capabilities of near-surface VMI (NS-VMI) through the analysis of speed and angular distributions derived from the images.

Source: The Journal of Physical Chemistry A

DOI: 10.1021/acs.jpca.5c08379

Authors: Nitish Pal, Preeti M. Mishra, Paul D. Lane, Matthew L. Costen, Kenneth G. McKendrick, Stuart J. Greaves

Institution: Heriot-Watt University

Language: English

Topic: Laser-Matter Interactions and Applications

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Funder: Engineering and Physical Sciences Research Council

Award: New Directions in Molecular Scattering: Multiple Pathways and Products