Multi-parameters optimization and matching analysis simulation studies of the linac for high-energy electron radiography

The electron linear accelerator, dedicated for high-energy electron radiography (HEER) experimental studies, was developed by the Institute of Modern Physics (IMP), Chinese Academy of Sciences (CAS). At present, some HEER experiments have been carried out in the operation stage and further requirements are put forward for lower beam emittance, lower energy spread and better uniformity at the exit of LINAC to enhance radiography quality. This paper uses the General Particle Tracer (GPT) code to perform global optimization studies based on the current beam line setup. The beam injection angle of alpha magnet and the model of the beam scraper are re-optimized. The influence of each factor on the beam parameters is comprehensively considered, and especially the influence of the space charge effect was analyzed by simulation studies. In order to suppress the deterioration of the beam quality in the alpha magnet, this paper take the lead in researching the relationship of the transverse phase space characteristics and the emittance growth and summarizes the rules for beam matching at the alpha magnet. The detailed simulation and analysis studies are presented in this paper.