Simulation study for electro-optic sampling measurement of low-energy electron beam

Abstract

For the successful optimization of the injector part of X-ray free-electron laser (XFEL) facilities, the temporal properties of the beam at the exit of the gun must be measured in a nondestructive way when the energy of the electron beam is 4-6 MeV. Electro-optic sampling (EOS) is a promising method of measuring the electron bunch length nondestructively. A simulation study is carried out with the pulse propagation method, which utilizes the Fourier transform to investigate the evolution of the electromagnetic pulse inside the electro-optic (EO) crystal. In our work, the properties of the 4.5 MeV electron beam are studied with the rings of charge for several values for the distances between the electron beam and the probe laser. The simulation result shows that the bunch length of the electron beam at the exit of the gun is measurable nondestructively by EOS.