| 摘要 |
PROBLEM TO BE SOLVED: To restore collapse in a facet provided at a front end part of an emitter, in a state where an electron gun is attached to an electron beam application device.SOLUTION: An extraction electrode power supply connected to an extraction electrode provided so as to be opposed to a thermoelectric field emission type emitter applies to the emitter both a normal operation forward voltage of a positive polarity and a reverse voltage of a negative polarity by switching. By switching the polarity of the voltage applied from the extraction electrode power supply to the extraction electrode to the reverse voltage, collapse in a facet provided at a front end part of the emitter is restored in a state where an electron gun is attached to an electron beam application device. |
