3d computer modelling of phase control in a magnetron through the output system

Summary form only given. 3D computer modelling of phase locking in a magnetron was reported last year. The locking signal was directly injected through the cathode when the magnetic field was uniform. For technical reasons, the injection through the cathode could not be tested, but the phase-locking was successfully achieved by injecting the signal through the output system. In the paper, we describe the computer modelling of phase control in an X-band pulsed rising-sun magnetron using MAGIC3D, by injecting the locking signal through the output system. In the modelling of phase control, the external parameters are kept constant so that the injected signal of varying frequency and amplitude can only affect the space charge, i.e. the equivalent reactance of the system; this in turn influences the frequency and phase of the output signal. It has been shown in the model that the output phase of the magnetron can be well controlled; it has been observed that in the process the injection signal eliminates the initial space charge noise and consequently speeds up the start-up of oscillations for both uniform magnetic field and the practical magnetic field measured in the real magnetron. It has also been found that the stronger the power of the control source, the more rapid is the frequency locking process. Also the MAGIC3D modelling confirmed the well known properties of the Alder curve. Since then we were able to build a tube and obtain some experimental results