Filming Enhanced Ionization in an Ultrafast Triatomic Slingshot

TL;DR

This paper demonstrates filming of ultrafast molecular motion, specifically a 'slingshot' effect in water, revealing how rapid atomic movements during ionization can distort imaging results and how understanding this can improve molecular imaging techniques.

Contribution

The study uncovers the geometry and mechanism of ionization enhancement during ultrafast molecular motion, improving the accuracy of Coulomb Explosion Imaging in polyatomic molecules.

Findings

Filmed rapid 'slingshot' motion in water molecules.

Identified how ultrafast motion distorts CEI results.

Uncovered the mechanism behind ionization enhancement.

Abstract

Filming atomic motion within molecules is an active pursuit of molecular physics and quantum chemistry. A promising method is laser-induced Coulomb Explosion Imaging (CEI) where a laser pulse rapidly ionizes many electrons from a molecule, causing the remaining ions to undergo Coulomb repulsion. The ion momenta are used to reconstruct the molecular geometry which is tracked over time (i.e. filmed) by ionizing at an adjustable delay with respect to the start of interatomic motion. Results are distorted, however, by ultrafast motion during the ionizing pulse. We studied this effect in water and filmed the rapid "slingshot" motion that enhances ionization and distorts CEI results. Our investigation uncovered both the geometry and mechanism of the enhancement which may inform CEI experiments in many other polyatomic molecules.