Abstract:
A thermionic electron emission device includes an insulating substrate, and one or more grids located thereon. The one or more grids include(s) 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. Wherein the thermionic electron emitter includes a carbon nanotube film structure.
Abstract:
Disclosed is an x-ray tube including a hybrid electron emission source, which uses, as an electron emission source, a cathode including both a field electron emission source and a thermal electron emission source. An x-ray tube includes an electron emission source emitting an electron beam, and a target part including a target material that emits an x-ray as the emitted electron beam collides with the target part, wherein the electron emission source includes a thermal electron emission source and a field electron emission source, and emits the electron beam by selectively using at least one of the thermal electron emission source and the field electron emission source.
Abstract:
Provided is a Schottky emitter having the conical end with a radius of curvature of 2.0 μm on the emission side of an electron beam. Since a radius of curvature is 1 μm or more, a focal length of an electron gun can be longer than in a conventional practice wherein a radius of curvature is in the range of from 0.5 μm to not more than 0.6 μm. The focal length was found to be roughly proportional to the radius of the curvature. Since the angular current intensity (the beam current per unit solid angle) is proportional to square of the electron gun focal length, the former can be improved by an order of magnitude within a practicable increase in the emitter radius. A higher angular current intensity means a larger beam current available from the electron gun and the invention enables the Schottky emitters to be used in applications which require relatively high beam current of microampere regime such as microfocus X-ray tube, electron probe micro-analyzer, and electron beam lithography system.
Abstract:
A method for making a thermionic electron emission device. The method includes the following steps. First, an insulating substrate is provided. Second, a number of lattices are formed on the insulating substrate. Third, a first electrode and a second electrode are fabricated in each lattice on the insulating substrate. Fourth, a carbon nanotube film structure is provided and at least part of the carbon nanotube film is suspended structure above the insulating substrate. Sixth, excess carbon nanotube film structure is cut away to obtain a number of thermionic electron emitters. The thermionic electron emitters are spaced from each other and located between the first electrode and the second electrode in each lattice.
Abstract:
A method for making a thermionic electron emission device. The method includes the following steps. First, an insulating substrate is provided. Second, a number of lattices are formed on the insulating substrate. Third, a first electrode and a second electrode are fabricated in each lattice on the insulating substrate. Fourth, a carbon nanotube film structure is provided and at least part of the carbon nanotube film is suspended structure above the insulating substrate. Sixth, excess carbon nanotube film structure is cut away to obtain a number of thermionic electron emitters. The thermionic electron emitters are spaced from each other and located between the first electrode and the second electrode in each lattice.
Abstract:
A thermionic electron emission device includes an insulating substrate and one or more lattices located on the insulating substrate. Each lattice includes a first, second, third and fourth electrode down-leads located on the insulating substrate to define an area. A thermionic electron emission unit is located in the area. The thermionic electron emission unit includes a first electrode, a second electrode, and a thermionic electron emitter. The thermionic electron emitter includes a carbon nanotube film structure. The carbon nanotube film structure includes a carbon nanotube film. The carbon nanotube film includes a number of carbon nanotubes joined end to end along axial directions of the carbon nanotubes by contacting with each other directly.
Abstract:
A thermionic electron source includes a substrate, at least two electrodes, and a thermionic emitter. The electrodes are electrically connected to the thermionic emitter. The thermionic emitter has a film structure. Wherein there a space is defined between the thermionic emitter and the substrate.
Abstract:
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.
Abstract:
An electron source is made from mixed-metal carbide materials of high refractory nature. Producing field-enhanced thermionic emission, i.e., thermal-field or extended Schottky emission, from these materials entails the use of a certain low work function crystallographic direction, such as, for example, (100), (210), and (310). These materials do not naturally facet because of their refractory nature. The disclosed electron source made from transition metal carbide material is especially useful when installed in a scanning electron microscope (SEM) performing advanced imaging applications that require a high brightness, high beam current source.
Abstract:
A carbon nanotube micro-tip structure includes an insulating substrate and a patterned carbon nanotube film structure. The insulating substrate includes a surface. The surface includes an edge. The patterned carbon nanotube film structure is partially arranged on the surface of the insulating substrate. The patterned carbon nanotube film structure includes two strip-shaped arms joined at one end to form a tip portion protruded from the edge of the surface of the insulating substrate and suspended. Each of the two strip-shaped arms includes a plurality of carbon nanotubes parallel to the surface of the insulating substrate.