Injector Physics Design at SHINE

SHINE high brightness injector is one of the key components of the x-ray FEL facility. It consists of a NC photocathode gun, a buncher, three solenoids, two accelerator cryomodule to boost the beam over 100 MeV. In addition, a laser heater, the pulse extraction system and several beam measurement section are included in the injector. In this paper, we describe the injector physics design including the beam performance, beam diagnosis and beam feedback.