| 主权项 |
1. An electron beam emitter comprising:
an electron emission source capable of emitting electrons; a vacuum chamber containing the electron emission source; and a transmission window that keeps airtightness of the vacuum chamber and is capable of transmitting the electrons from the electron emission source, the transmission window including a transmission portion that transmits the electrons and a non-transmission portion that does not transmit the electrons, the electron emission source including an emission portion that emits the electrons and a non-emission portion that does not emit the electrons, the emission portion having a lower work function than the non-emission portion, the non-emission portion being created so as to prevent the electrons from reaching the non-transmission portion. |
