Transformation and Adaptation of the Kiloampere Electron Beam Generated in the Linear Induction Accelerator for Pumping a Terahertz FEL

The project of a THz free electron laser (FEL) based on a high-current relativistic electron beam is under development at the BINP together with the IAP RAS. In order to drive this FEL it is planned to use the electron beam (energy up to $E_{e}=5-$ 10 MeV, current up to $I_{b}=1\ \mathbf{kA}$ , pulse duration up to $\tau_{b}=100$ ns, normalized emittance $\sim 550\ \pi\cdot mm \cdot mrad$ ) generated at the new linear induction accelerator (LIA). In the framework of previous theoretical work, it was shown that such an electron beam is a suitable driver for an FEL-system based on Bragg reflectors [1]. The proposed FEL scheme allow us to generate coherent pulses of submillimeter radiation in the frequency range of 0.3 – 1.2 THz with a sub-gigawatt power level and high energy content (up to ~ 100 J). In the report, we will discuss the main tasks of the project, the methods for their solution and the overall technical project of the FEL.