| 摘要 |
PROBLEM TO BE SOLVED: To provide an electron gun which makes it possible to select energy well in response to the acceleration of a beam and control the energy and power of the gun separately. SOLUTION: An electron gun for a high-output electron accelerator has a housing for intercepting the radiation generated by the accelerator. Inside the housing, the electron gun has an anode plate with a central aperture, a diffuser cathode that emits electrons, a Wehnelt focusing electrode assembly that focuses the electrons emitted by the cathode through the aperture of the anode plate and an electrical resistance heater connected with the cathode to heat it. Outside the housing, the electron gun also ahs a device for responding to a control signal to energize the heater, a control device that generates control signal pulses at a prescribed repetition rate over a duration to allow the cathode to emit the electrons for a prescribed duration. The control device responds to a signal indicating the resistance of the heater so as to send out only enough energy to maintain the resistance of the heater at a prescribed value to a device that energizes the heater.
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