Project of Powerful Long-pulse THz-band FEL with Talbot-type Cavity: Design and Optimization

Currently, active work is being carried out to create a free-electron laser (FEL) on the basis of a long-pulse (hundreds nanoseconds) 5–10MeV /1–2kA electron beam with close-to-GW level of the output power at THz frequencies. An important problem here is the design of a cavity which must inevitably be highly oversized in both the transverse and axial directions, but, at the same time, provide single-frequency generation of a given operating mode. In this work, we develop the theory of a FEL based on the use of excitation of a supermode of the Talbot-type cavity.