| 摘要 |
PURPOSE: An electron gun with a cold cathode is provided to be capable of easily mounting a heating cathode to the electron gun and assuring an insulating distance by mounting the cold cathode to the electron gun as well as forming a means for maintaining the insulating distance between the cold cathode and a first grid electrode. CONSTITUTION: Spacers(122) having a suitable height and a constant shape are installed between a first grid electrode(103) and the cold cathode and are inserted into forced fitting grooves(103a) formed on both sides of respective electron beam through holes(111) of the first grid electrode(103). Preferably, the spacers have an aspect ratio equal to or more than 1 and a specific permittivity equal to or less than 10.
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