Method of Kinetic Energy Reconstruction from Time-of-Flight Mass Spectra

TL;DR

This paper introduces a simulation-based method for reconstructing ion kinetic energy distributions from time-of-flight spectra, accommodating complex spectrometer geometries and improving accuracy through calibration.

Contribution

The paper presents a novel calibration and simulation approach for kinetic energy reconstruction from time-of-flight spectra, applicable to complicated geometries and anisotropic efficiencies.

Findings

Successfully reconstructed time-resolved kinetic-energy-release spectra.

Improved agreement between simulated and experimental spectra.

Applicable to complex spectrometer setups.

Abstract

We present a method for the reconstruction of ion kinetic energy distributions from ion time-of-flight mass spectra through ion trajectory simulations. In particular, this method is applicable to complicated spectrometer geometries with largely anisotropic ion collection efficiencies. A calibration procedure using a single ion mass peak allows the accurate determination of parameters related to the spectrometer calibration, experimental alignment and instrument response function, which improves the agreement between simulations and experiment. The calibrated simulation is used to generate a set of basis functions for the time-of-flight spectra, which are then used to transform from time-of-flight to kinetic-energy spectra. We demonstrate this reconstruction method on a recent pump-probe experiment by Asmussen et al. (J. D. Asmussen et al., Phys. Chem. Chem. Phys., 23, 15138, (2021)) on helium nanodroplets and retrieve time-resolved kinetic-energy-release spectra for the ions from ion time-of-flight spectra.