摘要:
A method of manufacturing carburized Lu2O3 doped Mo cathodes for thermionic emission for magnetrons is described. The Lu2O3 doped Mo powder is prepared by sol-gel method. The powder is reduced thoroughly in hydrogen atmosphere. Afterwards, the powder is die-pressed into pellets, followed by sintering in hydrogen and carburization in activated carbon powder to obtain the carburized Lu2O3 doped Mo cathode.
摘要:
An array of carbon nanotube micro-tip structure includes an insulating substrate and a plurality of patterned carbon nanotube film structures. The insulating substrate includes a surface. The surface includes an edge. A plurality of patterned carbon nanotube film structures spaced from each other. Each of the plurality of patterned carbon nanotube film structures is partially arranged on the surface of the insulating substrate. Each of the plurality of patterned carbon nanotube film structures comprises two strip-shaped arms joined together forming a tip portion protruding and suspending from the edge of the surface of the insulating substrate. Each of the two strip-shaped arms comprises a plurality of carbon nanotubes parallel to the surface of the insulating substrate.
摘要:
Embodiments of the disclosure relate to electron emitters for use in conjunction with X-ray emitting devices. In certain embodiments the emitter includes features that prevent, limit, or control deflection of the electron emitter at operating temperatures. In this manner, the electron emitter may be kept substantially flat or at a desired curvature during operation.
摘要:
An improved cathode comprises a cone-shaped emitter with a carbon-based coating applied to the emitter cone surface, in which there is a narrow annular gap between the emitter body and the carbon coating. The gap prevents direct contact between the carbon coating and the crystalline emitting material, thereby preventing damaging interactions and extending the useful lifetime of the cathode.
摘要:
Impregnated rare earth metal-containing barium-aluminum-scandate cathodes with a rare earth oxide doped tungsten matrix and methods for the fabrication thereof are described. In one aspect, an impregnated rare earth metal-containing barium-aluminum-scandate cathode comprises: a rare earth oxide doped tungsten matrix, and an impregnated active substance. The active substance comprises scandium oxide (Sc2O3), a second rare earth oxide, and barium calcium aluminate, wherein the molar ratio of Ba:Ca:Al is about 4:1:1.
摘要:
A method for making a thermionic electron source includes the following steps: (a) supplying a substrate; (b) forming a first electrode and a second electrode thereon; and (c) spanning a carbon nanotube film structure on a surface of the first electrode and the second electrode with a space defined between the thermionic emitter and the substrate.
摘要:
A thermionic emission device includes an insulating substrate, and one or more grids located thereon. Each grid includes a first, second, third and fourth electrode down-leads located on the periphery thereof, and a thermionic electron emission unit therein. The first and second electrode down-leads are parallel to each other. The third and fourth electrode down-leads are parallel to each other. The first and second electrode down-leads are insulated from the third and fourth electrode down-leads. The thermionic electron emission unit includes a first electrode, a second electrode, and a thermionic electron emitter. The first electrode and the second electrode are separately located and electrically connected to the first electrode down-lead and the third electrode down-lead respectively. The thermionic electron emitter includes at least one carbon nanotube wire.
摘要:
An exemplary electron emission device includes an electron emitter, an anode opposite to and spaced apart from the electron emitter, a first power supply circuit, and a second power supply circuit. The first power supply circuit is configured for electrically connecting the electron emitter and the anode with a power supply to generate an electric field between the electron emitter and the anode. The second power supply circuit is configured for electrically connecting the electron emitter with a power supply to supply a heating current for heating the electron emitter whereby electrons emit therefrom. Methods for generating an emission current with a relatively higher stability also are provided.
摘要:
A method for making a thermionic electron source includes the following steps: (a) supplying a substrate; (b) forming a first electrode and a second electrode thereon; and (c) spanning a carbon nanotube film structure on a surface of the first electrode and the second electrode with a space defined between the thermionic emitter and the substrate.
摘要:
A thermionic electron source includes a substrate, two electrodes, and a thermionic emitter. The thermionic emitter is electrically connected to the two electrodes. The substrate has a recess formed on a surface thereof, and the thermionic emitter is located on the surface of the substrate corresponding to the recess.