On the theory of a plasma-beam superheterodyne free-electron laser with H-ubitron pumping

The scheme of a plasma-beam superheterodyne free-electron laser (PBSFEL) with H-ubitron pumping is analyzed and several possible variants of its practical implementation are considered. Some variants represent sources of highly monochromatic signals, while the other generate signals with a rather broad spectrum. The increment of wave growth in PBSFELs is estimated and it is established that, under otherwise equal conditions, these FELs are characterized by much greater gain increments than the equivalent two-stream devices. The proposed PBSFELs have good prospects as sources of high-power electromagnetic radiation in the millimeter wavelength range.