Patent ID: 8436524
Filing Date: 2013-05-07
Classification: H01J

Abstract:
1. An electron source, comprising: a monocrystalline metal needle rod comprising a reservoir of metal oxide coating a surface of the monocrystalline metal, having an electron emitting portion at a first end of the rod; a cup-shaped heat-transmitting portion connected to a second end of the rod different from the first end; and an electrothermal conversion portion, which heats the heat-transmitting portion, wherein the electrothermal conversion portion is comprised inside a cavity provided in the heat-transmitting portion, in a state of non-contact with the heat-transmitting portion, the heat-transmitting portion and the rod have an integrally molded structure comprising a monocrystal of tungsten, molybdenum, iridium, niobium, tantalum, or rhenium, and a reservoir for diffusing an oxide of metallic elements is provided in the monocrystal of the rod.