High-resolution imaging of C + He collisions using Zeeman deceleration and VUV detection

TL;DR

This paper demonstrates high-resolution, state-resolved imaging of C + He collisions using Zeeman deceleration and VUV detection, enabling detailed comparison with quantum scattering predictions.

Contribution

First implementation of recoil-free VUV detection in decelerated collision experiments, allowing for unprecedented resolution in angular scattering measurements.

Findings

Resolved diffraction oscillations in angular distributions

Excellent agreement with quantum scattering calculations

Enhanced capability for studying scattering processes

Abstract

High-resolution measurements of angular scattering distributions provide a sensitive test for theoretical descriptions of collision processes. Crossed beam experiments employing a decelerator and velocity map imaging have proven successful to probe collision cross sections with extraordinary resolution. However, a prerequisite to exploit these possibilities is the availability of a near-threshold state-selective ionization scheme to detect the collision products, which for many species is either absent or inefficient. We present the first implementation of recoil-free vacuum ultraviolet (VUV) based detection in scattering experiments involving a decelerator and velocity map imaging. This allowed for high-resolution measurements of state-resolved angular scattering distributions for inelastic collisions between Zeeman-decelerated carbon C($^3P_1$) atoms and helium atoms. We fully resolved diffraction oscillations in the angular distributions, which showed excellent agreement with the distributions predicted by quantum scattering calculations. Our approach offers exciting prospects to investigate a large range of scattering processes with unprecedented precision.