ON THE DESIGN OF ELECTRON GUNS FOR CYCLOTRON-RESONANCE MASERS UTILIZING TROCHOIDAL ELECTRON-BEAMS (TROCHOTRONS)

The properties of crossed-field electron guns which are capable of pro viding the required trochoidal beams for efficient cyclotron resonance interaction in the trochotron configuration are analyzed, A discussio n of the beam parameters that are used to characterize the device perf ormance is included in a general description of the operation of these guns, Two concrete designs are presented and are used to demonstrate the performance capabilities of these devices with respect to the beam self-fields, the externally applied electric and magnetic fields, and the electrode geometry. It is shown that these devices, which; typica lly generate beams with large ratios of perpendicular to parallel (dri ft) velocity, are capable of producing extremely small drift velocity spreads over a wide range of parameters.