Subcritical-voltage magnetron RF power source

A system for powering an accelerating cavity, comprising:

• a first power source configured to receive an input injection-locking signal and produce an injection-locked first output signal using the input injection-locking signal;
• a second power source coupled to the first power source and configured to receive the injection-locked first output signal and produce a second output signal, the second power source including a high-power magnetron receiving a cathode voltage, the cathode voltage controlling a power of the second output signal;
• and
• a voltage supply system coupled to the second power source and configured to control the power of the second output signal by providing a subcritical feeding voltage as the cathode voltage, the subcritical voltage below a critical voltage needed for self-excitation of the high-power magnetron.