Start-to-end Simulation For The IR-FEL Facility

An infrared free electron laser facility(FELiCHEM)is being constructed at University of Science and Technology of China(USTC)with the aim of developing an experimental system for energy chemistry.This large-scale experimental device will be the first set of IR-FEL user device.It will meet the urgent needs of energy and chemical research and make China reach the international advanced level in the low-gain FEL oscillator device research.The movement of electron beam in the whole transport line is very complicated.The electron beam is generated in the electron gun,accelerated by the accelerating tube and transported to the transmission line,into the undulator to produce FEL radiation.In order to obtain the more higher FEL power,the electron beam at the entrance of the undulator has to meet the design requirements in terms of energy,energy spread,beam current and emittance.In this paper,the LATTICE of the light source is designed on the basis of the FEL requirement and the beam parameters provided by the electron gun simulation,and the related design is verified by numerical simulation.In this paper,we used MADX to obtain a feasible Lattice structure through parameter optimization based on the previously designed structure and related research background.Start-to-end simulations include the injector,linac,beam transport line,and undulator,To accurately perform these S2E simulations,multiple codes are required to correctly capture the physics in each region of the machine.Parmela was used to simulate the injector and LATTICE parameter optimization was handled by MADX,the transport line and error analysis were handled by ELEGANT,At the FEL undulator,Optical Propagation Code was used to simulate the propagation of light through the optical cavity and cooperates with Genesis to simulate gain process in the undulator.