Measured performance of magnetron injection guns for gyrotrons
Magnetron injection guns (MIGs) are a principle component in gyrotrons and gyroklystrons. The performance of the RF device critically depends on the performance of the MIG that provides the electron beam. Unfortunately, recent measurements indicate that MIGS often generate asymmetrical electron beams that can adversely impact the operation of the RF source. This presentation will describe the measurement facility and provide results from recent tests.
Experimental study of gyrotron efficiency enhancement by improvement of electron beam quality
The methods for suppressing parasitic low- frequency oscillations (LFOs) have been applied to improve electron beam quality in a 4-mm 100-kW gyrotron. In the conditions of suppressed LFOs and of high cathode emission uniformity, the stable operation of this gyrotron at pitch factor values high than 1.5 has been achieved. As a result, the efficiency of the gyrotron at the main TE12,3 mode has been increased from 32 % (corresponds to the designed regime with pitch factor of 1.28) up to 42 %.
Experimental studies of gyrotron electron beam systems
In order to provide electron beams of powerful gyrotrons, magnetron-injection guns operating in the regime of the temperature limited current are used. The electron beam quality and gyrotron performances are defined both by the cathode emission processes and the processes occurring in the electron beam during its formation and transportation. The results of measurements of the energy spectrum and velocity spread of the gyrotron electron beam in different regimes are given. Experimental data on the parameter of efficient emission inhomogeneity for different regimes are presented, as well as the dependencies of electron beam parameters on efficient inhomogeneity of the cathode.