Electron gun and system and method using electron gun

An electron beam system comprising:

• an electron gun comprising:
• a heating power supply with an electrical contact for cathode heating;
• a high voltage power supply;
• a bias voltage power supply;
• a moving cathode station comprising:
• a plurality of cathodes positioned on the moving station at a predetermined distance and heated by the heating power supply, each of the plurality of cathodes configured to emit thermal electrons from an emission tip;
• and
• a plurality of bias cups, the plurality of cathodes and the plurality of bias cups operatively coupled to the bias voltage power supply to control a thermal electron emission region by applying a bias voltage to the bias cup, each of the plurality of bias cups electrically coupled to a respective cathode forming a pair of cathode and bias cup in the cathode station, each of the plurality of bias cups having an opening with a predetermined size to control a number of the thermal electrums passing through the opening of the respective bias cup and to focus the thermal electrons;
• a moving anode station comprising:
• a plurality of anodes having a base portion with a base opening and an upper portion extending upwardly from a base portion having a focus opening to focus the thermal electrons accelerated from the cathode through the anode's openings;
• an automated beam changer configured to move the cathode station and the anode station comprising:
• a cathode station system comprising a driver in communication with the moving cathode station to move the cathode station to connect a desired cathode and bias cup pair with the electrical contacts of the heating power supply;
• and
• an anode station system comprising a driver in communication with the moving anode station to move the anode station such that a position of a selected anode in the anode station is aligned with a position of a respective matching pair of cathode and bias cup of the cathode station to generate an electron beam with predetermined dimensions and parameters;
• and
• a controller configured to control a bias voltage between the cathode and the matching bias cup in the cathode station, voltage and current limit provided to the electron beam gun by the high voltage power supply and to control the drivers of the rotating cathode and anode rotating stations to synchronize and align a predetermined cathode and bias cup pair to a predetermined anode to control the parameters of the generated electron beam.