Start-to-end self-consistent simulation of the UEM beamline

Abstract

Addressing the preliminary design review report of the ultrafast electron microscope (UEM), start-to-end self-consistent simulations were carried out to explore fundamental aspects affecting the resolution (space-charge effects, energy spread, shot-to-shot energy jitter, contrast formation, etc.). The electron beam energy spread in the single-shot mode and the effective energy spread in the accumulation mode, equivalent to the convolution of the single-shot energy spread and shot-to-shot energy jitter, have been identified as the ultimate limits of the instrument resolution. A full self-consistent simulation from the photocathode to the detector is being performed using the GPT code to find out what resolution can be achieved. Preliminary results of the start-to-end simulations are reported in this note and the plan of further simulations is presented.