The study of an independent tunable electron gun for a compact Terahertz Source Based on Free Electron Lasers

In this paper an independent tunable electron gun for a compact terahertz source based on free electron lasers is studied. In order to obtain a compact terahertz source, an electron gun played a dominant role. In this paper an independent tunable electron gun was designed and calculated. The gun was composed of two independent cavities. The feeding and the phase are independent, respectively. The acceleration of electron beams was calculated 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 alpha magnet is not needed. Thus, a compact Terahertz source can be obtained. In order to illustrate that case, the acceleration of these electron beams in a linac was calculated. When the feeding power is 7.0 MW, 10 MeV, the energy of electron beams, can be obtained at nearly 0.744-0.745 m. the energy spread and the length of micropulse were satisfied with the THz radiation. The impedance of the linac was constant.