| Abstract: | To meet the requirements of high performance THz-FEL(Free Electron Laser),a compact scheme of FEL injector was proposed.A thermionic cathode was chosen to emit electrons instead of a photo-cathode with its complex structure and high cost.The effective bunch charge was improved to~200 pC by adopting an enhanced EC-ITC(External Cathode Independently Tunable Cells)RF gun to extract micro-bunches;back bombardment,effects were almost eliminated as well.Constant gradient accelerator structures were designed to improve energy to~14 MeV,while the focusing system was applied for emittance suppressing and bunch state maintenance.The physical design and beam dynamics of the key components for the FEL injector were analyzed.Furthermore,startto-end simulations with multi-pulses were performed using homemade MATLAB and Parmela.The results show that continual high brightness electron bunches with a low energy spread and emittance could be obtained stably. |
