External grid-controlled hot cathode array electron gun

An external grid-controlled hot cathode array electron gun, comprising:

• an insulated cathode base;
• a filament, the filament being in form of a strip and mounted on a surface of the cathode base;
• a plurality of hot cathode emission elements mounted on a surface of the filament facing away from the cathode base;
• and
• a grid-controlled structure comprising an insulated grid-controlled structure body and a plurality of through holes provided in the grid-controlled structure body, one side of the grid-controlled structure body abutting against the cathode base so that the filament is held between the grid-controlled structure body and the cathode base, and so that the plurality of hot cathode emission elements on the surface of the filament are inserted into the plurality of through holes, respectively.