The study of some key technologies for a compact Terahertz Source Based on Free Electron Lasers

In this paper some key technologies of a compact Terahertz Source Based on Free Electron Lasers are studied. In order to obtain a compact Terahertz Source, an independent tunable electron gun played a dominant role. The independent tunable electron gun was calculated firstly. The electron gun can create high-brightness and short-pulse beams (less than 2 ps). The energy spread is less than 0.5%, the normalized rms beam emittance and longitudinal rms emittance are both low. So the α magnet is not needed. Secondly, electron beams accelerated in a linear accelerator are calculated. By designing the linac carefully the energy of these electron beams, 10MeV can be obtained in nearly 0.6m and the energy spread is also less than 0.5%. Thus these electron beams emerging from the linac enter an undulator and the Terahertz radiation is emitted from these beams by a bending magnet. The dimensions of the whole system are less than 3 m³. A compact Terahertz source can be obtained.