Wide Tunable Sub-THz Gyrotron with Shortened Cavity and Increased Current

The possibility of a kW-level tunable (up to 5%) source of sub-THz radiation based on a gyrotron with a shortened cavity and an increased operating current is proposed. Wide tunability is achieved due to excitation of large number of cavity axial modes which possess the weaker sensitivity to the electrons velocity spread in the shortened interaction space. The project of 0.2 THz gyrotron with an output power of 1 kW within the frequency tuning band of ~10 GHz is proposed. The design of a magnetron-injection gun able to provide the helical electron beam with required current up to 2 A (50% from the Lengmur current) and good enough beam quality is also discussed.