• V.Yu. Zaslavsky, N.S. Ginzburg, A. Malkin, N.Yu. Peskov, A. Sergeev
  IAP/RAS, Nizhny Novgorod
• K.K. Kamada, Y. Soga
  Kanazawa University, Kanazawa

Periodical Bragg structures may be considered as an effective way of controlling the electromagnetic energy fluxes and provision of spatially coherent radiation in the free electron lasers with oversized interaction space. A new scheme of terahertz band FEL with hybrid Bragg resonator consisting of advanced input Bragg mirror and traditional output Bragg mirror is proposed. Advanced Bragg mirror exploits coupling between two counter-propagating waves and the quasi cutoff wave and provides mode selection over the transverse index. Main amplification of the synchronous wave by the electron beam takes place in the regular section of the resonator. Small reflections from the output traditional Bragg mirror are sufficient for the oscillator self-excitation. Results of simulation of nonlinear dynamics of the FEL with a hybrid Bragg resonator is presented and demonstrate its operability in the terahertz frequency band with high (megawatt level) radiation power. In difference with the existing terahertz band FELs [1-2], the above scheme would be driven by a long pulse (microsecond) electron beam from Induction linear accelerators or Electrostatic accelerators.

[1] V.P. Bolotin, et al., Nucl. Instr. & Meth. Phys. Res. A, 2005, v.543, p.81.
[2] Y.U. Jeong, et al., Nucl. Instr. & Meth. Phys. Res. A, 2004, v.528, p.88.