High efficiency FEL-oscillator with Bragg resonator operated in the reversed guide field regime

Abstract

Abstract The narrow-band high-efficiency FEL-oscillator with Bragg resonator operated in the reversed guide field regime was realized on the basis of linear induction accelerator formed 1 MeV, 200 A, 200 ns electron beam. At a frequency of31 GHz radiation with a power of 23 MW and an efficiency of 19% was registrated. The measured frequency bandwidth was less than the zone of effective reflection of the Bragg mirrors. The narrow width of the spectrum was encouraged by the selective properties of the Bragg resonator in combination with the high quality of the helical electron beam formed in the reversed guide field regime.