Investigating the transverse jitter in ultrashort electron beam generation with optical compression

Abstract Optical compression scheme is a highly potential candidate for the generation of ultrashort electron beam. This scheme utilizes a tightly focused radially polarized laser to compress the electron beam from the photocathode radio frequency (RF) gun. However, the unavoidable relative transverse jitter between the electron beam and the modulation laser leads to a performance degradation of the compressed pulse duration. To address this issue, we propose a method for correcting this transverse jitter through a specific design of optical system and an optimized decoupled solenoid. This method concentrates on the transverse jitter caused by the pointing instability of the laser. Its objective is to align both the transverse jitter direction and magnitude of the modulation laser with that of the electron beam. The simulation results demonstrate that the deleterious impact of transverse jitter can be effectively mitigated by this method, thereby ensuring the sustained generation of high-quality ultrashort electron beams.