Electrodynamic System of a Powerful THz Band Free Electron Laser Based on the LIU Linear Induction Accelerator: Modeling and Cold Tests

The authors describe the current stage of the development of a powerful long-pulse free electron laser (FEL) of the terahertz band at the Budker Institute of Nuclear Physics in cooperation with Institute of Applied Physics on the basis of the LIU induction accelerator with an energy of 5–10 MeV, a current of up to 2 kA, and a pulse duration of up to 200 ns. It is proposed that two alternative types of electrodynamic systems may be used to ensure a regime of stable narrow band generation: advanced Bragg resonators and quasi-optical resonators of the Talbot type. FEL parameters calculated on the basis of these resonators are presented, along with results from modeling under conditions of substantial oversize. The operability of the new types of resonators is verified in cold electrodynamic tests.