Error Tolerance Characterization for the HUST MeV Ultrafast Electron Diffraction System

Abstract

Ultrafast electron diffraction (UED) is a powerful tool for probing atomic dynamics with a femtosecond resolution. Such a spatiotemporal resolution requires error tolerance for the UED system which includes the RF system, the laser system, the beamline elements, etc. To characterize the error tolerance of the required spatiotemporal resolution for the 1.4-cell MeV UED we are developing, we use ASTRA to simulate the UED model with errors including initial transverse beam centroid offset, RF amplitude jitter and injection phase jitter, etc. By performing simulations with different errors omitted, we can characterize the contribution of each error and thus set the tolerance for each error to obtain the required performance of UED experiment. In the end, we present the error tolerance for 10% emittance growth and 100 fs time of flight variation to maintain the required spatiotemporal resolution.