Start to End Simulation for A Compact THz-FEL

An oscillator type terahertz free electron laser (THz-FEL) is under construction at Huazhong University of Science and Technology (HUST). The designed electron beam energy ranges from 8 MeV to 14 MeV, and the radiation frequency ranges from 3 THz to 10 THz. FEL requires high quality electron beams of emittance, energy spread, bunch charge etc. To know the overall facility performance, a start to end simulation (from electron gun to the end of the oscillator) of the THz-FEL is performed. The simulation of the electron gun to the exit of the linac is performed using PARMELA, where the effect of space charge effects is considered. In addition, the effect of beam loading effect is considered for the linac. The transport line is matched and simulated using ELEGANT. GENESIS 1.3 and OPC is used for the lasing process. Results of the simulation are presented and discussed in this paper.