Operating Characteristics of a Relativistic Magnetron with a Washer Cathode

We have determined the operating characteristics of a six-vane MIT-A6 magnetron. The high-power resonant microwave emission at 2.83 GHz is in good agreement with the ?-mode oscillation predicted by the Buneman-Hartree threshold. We studied the magnetron performance as a function of applied voltage, magnetic field, and extraction geometry. Maximum power is obtained with three open vanes. Using a simple energy balance model we obtain good agreement between the computed and measured peak power.