The simulations of spatially extended free-electron masers (FEM) of planar geometry based on the use of a three-dimensional distributed feedback mechanism, which is implemented in the so-called “three-dimensional” Bragg structures, is carried out. The possibility of creating an FEM of this type in the W-band based on high-current explosive emission accelerator “U-2” (BINP RAS) forming a sheet electron beam of 1 MeV / 140 kA / 10 μs with a cross section of 1 cm × 140 cm is studied. The possibility of implementing a stable narrow-band generation regime in the FEM under development at optimal parameters with an electron efficiency of ∼ 18–20% and a record output power of up to ∼ 20 GW level is demonstrated.
Peskov et al. (Wed,) studied this question.