Regulated charged particle beam emitter systems and methods

A beam injector comprising:

• a heater disposed proximate a cathode emitter, the cathode emitter configured to emit electrons when heated by the heater;
• a first electrode configured to bias at least a portion of the electrons to remain on the cathode emitter and focus the emitted electrons into an electron beam;
• a first resistor coupled between the cathode emitter and the first electrode and configured to allow self-regulation of a voltage potential on the first electrode based at least in part on a current of the electron beam;
• one or more second electrodes configured to focus and/or accelerate the electron beam;
• and
• one or more second resistors coupled between the one or more second electrodes and the cathode emitter and configured to regulate a voltage potential on the one or more second electrodes
• wherein the beam injector further comprises a target configured to receive the electron beam, and wherein the target is configured to generate radiation when contacted with the electron beam.