PURPOSE: To obtain an electron gun capable of forming electron beam profiles with optional shapes by providing many electron sources capable of adjusting the amount of electron emission individually and by emitting electrons from optional electron sources among many of them arranged.
CONSTITUTION: An electron gun body section except a power source and a switch group section is placed in a high vacuum of about 10-9-10-10 Torr, and keying switches corresponding to the electron sources desired for emission of electrons are turned on. For instance, if it is desired to activate one electron source shown at the upper left in the figure, a voltage can be applied between an anode electrode 11 and a cathode electrode 31 so as to emit electrons by turning a keying switch 61 on. In this case, by performing fine adjustments of nine variable resistors 51W59 independently the amount of electron emission from individual electron sources can be adjusted independently.
SAKAI CHIAKI
YASHIRO TAKEHISA
