# Space-Charge effect in electron time-of-flight analyzer for high-energy photoemission spectroscopy

## TL;DR

This paper investigates the space-charge effect in electron time-of-flight analyzers used in high-energy photoemission spectroscopy, comparing simulation methods and validating the accuracy of SIMION in predicting energy distortions.

## Contribution

It introduces and compares two simulation methods for space-charge effects and verifies SIMION's reliability for modeling these effects in photoemission experiments.

## Key findings

- SIMION accurately predicts energy distortions caused by space-charge effects.
- Comparison of two simulation methods shows consistent results.
- Validated simulation approach can improve interpretation of photoemission spectra.

## Abstract

The space-charge effect, due to the instantaneous emission of many electrons after the absorption of a single photons pulse, causes distortion in the photoelectron energy spectrum. Two calculation methods have been applied to simulate the expansion during a free flight of clouds of mono- and bi-energetic electrons generated by a high energy pulse of light and their results have been compared. The accuracy of a widely used tool, such as SIMION(R), in predicting the energy distortion caused by the space-charge has been tested and the reliability of its results is verified. Finally we used SIMION(R) to take into account the space-charge effects in the simulation of simple photoemission experiments with a time-of-flight analyzer.