초록 ▼

A long life high current density hollow cathode electron beam source for use in various E-beam apparatus which uses an ionizable gas within the hollow cathode. Bombardment of an electron emissive surface within the hollow cathode by energetic gas ions causes electrons to be emitted by secondary emis

A long life high current density hollow cathode electron beam source for use in various E-beam apparatus which uses an ionizable gas within the hollow cathode. Bombardment of an electron emissive surface within the hollow cathode by energetic gas ions causes electrons to be emitted by secondary emission rather than thermionic emission effects. Once initialized by an external ionization voltage the device is essentially self sustaining and operates near room temperature, rather than at thermionic emission temperatures, and with reduced voltages.

대표청구항 ▼

In an electron beam apparatus, the improvement which comprises a hollow cathode structure comprising an outer enclosure, having at one end thereof a wall, said wall having an aperture therethrough for electron beam emission, a second wall at the opposite end of said enclosure, the enclosure and wall

In an electron beam apparatus, the improvement which comprises a hollow cathode structure comprising an outer enclosure, having at one end thereof a wall, said wall having an aperture therethrough for electron beam emission, a second wall at the opposite end of said enclosure, the enclosure and walls defining an interior chamber, means for admitting an ionizable gas into said chamber, the interior surface of said chamber, exclusive of said end walls, having a low work function electron emissive coating thereon which readily emits electrons under bombardment by ions from said gas, and means for ionizing the gas within said chamber whereby high energy electrons are emitted from said surface by secondary emission effects and low energy electrons released by collision between said high energy electrons and gas ions are emitted through the aperture.