Drive Laser Temporal Shaping Techniques for Shanghai Soft X-Ray Free Electron Laser

The design of Shanghai soft X-ray free electron laser (SXFEL) is based on laser driven photocathode, which can provide normalized emittance <2.5 mm⋅mrad with 500 pC charge. The temporal shape of drive laser has significant influence on the electron beam brightness. This paper presents the transport line of drive laser system and the temporal shaping techniques for SXFEL. This drive laser produces 8 picosecond 266nm ultraviolet pulses with repetition rate 10Hz. A transverse deflecting cavity was used for indirectly characterizing the laser pulse temporal structure. Here we present the drive laser system with its temporal shaping method, and measurement results.