The influence of the Coulomb interaction in electron bunch on the structural parameters determined by time-resolved electron diffraction

TL;DR

This paper develops an analytical method to estimate how Coulomb repulsion in ultrashort electron bunches distorts diffraction patterns, affecting the accuracy of interatomic distance measurements in time-resolved electron diffraction.

Contribution

It introduces an analytical technique to quantify Coulomb-induced distortions in electron diffraction patterns for pulses shorter than 10 ps.

Findings

Coulomb repulsion causes measurable diffraction pattern deformation.

The method estimates distortion effects on interatomic distance accuracy.

Results help optimize electron pulse parameters for precise measurements.

Abstract

Transition to temporal resolution on the order of 1 ps or less raises a number of questions associated with estimation of the accuracy of the dynamic parameters based on the analysis of time-dependent scattering intensity. The use of ultrashort pulses leads to the necessity for increasing the total exposure time and lengthening the time of data acquisition. This can be to some extent mitigated by increasing the charge per pulse. Increasing in the number of electrons, however, is limited by the Coulomb repulsion between them, which leads on one hand, to distortion of the diffraction pattern, and the other hand to increase the duration of the pulse. The analytical technique for estimating the deformation of the diffraction pattern caused by the Coulomb repulsion of the electrons in the electron bunch with duration of less than 10 ps, and the influence of this effect on the accuracy of determination of the interatomic distances is developed.