Magnetron-Injection Gun with Increased Current for Frequency Tunable Medium Power Sub-THz Gyrotron.

A magnetron-injection gun able to provide very high ratio t_j≈ 0.5 of the beam current to the Langmuir current has been designed, while maintaining good enough quality and stability of a formed helical electron beam. The specific feature of the gun is the shape of the cathode with two singular points of the electric field distribution which ensure close to uniform electric field profile within the emitter ring for wide range of operating currents. The gun provides the smoothed dependence of the beam parameters for currents up to 1.5–2 A and is suitable for wide (~ 10 GHz) frequency range gyrotron operation with the central frequency of 0.2 THz and output power ~ 1 kW within the whole tuning band. Such approach for the magnetron-injection gun design can be used for development of other promising high power sub-THz gyrotrons. [ABSTRACT FROM AUTHOR]