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Field Emitter Array
A field emitter array (FEA) is a particular form of field electron emission, large-area field electron source. FEAs are prepared on a silicon substrate by lithographic techniques similar to those used in the fabrication of integrated circuits. Their structure consists of many individual, similar, small-field electron emitters, usually organized in a regular two-dimensional pattern. FEAs need to be distinguished from "film" or "mat" type large-area sources, where a thin film-like layer of material is deposited onto a substrate, using a uniform deposition process, in the hope or expectation that (as a result of statistical irregularities in the process) this film will contain a sufficiently large number of individual emission sites. Spindt arrays The original field emitter array was the ''Spindt array'', in which the individual field emitters are small sharp molybdenum cones. Each is deposited inside a cylindrical void in an oxide film, with a counterelectrode deposited on the t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silicon Carbide Field Emitter (8536018059)
Silicon is a chemical element; it has Symbol (chemistry), symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic lustre, and is a Tetravalence, tetravalent metalloid (sometimes considered a non-metal) and semiconductor. It is a member of carbon group, group 14 in the periodic table: carbon is above it; and germanium, tin, lead, and flerovium are below it. It is relatively unreactive. Silicon is a significant element that is essential for several physiological and metabolic processes in plants. Silicon is widely regarded as the predominant semiconductor material due to its versatile applications in various electrical devices such as transistors, solar cells, integrated circuits, and others. These may be due to its significant band gap, expansive optical transmission range, extensive absorption spectrum, surface roughening, and effective anti-reflection coating. Because of its high chemical affinity for oxygen, it was not until 1823 that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Field Electron Emission
Field electron emission, also known as field-induced electron emission, field emission (FE) and electron field emission, is the emission of electrons from a material placed in an electrostatic field. The most common context is field emission from a solid surface into a vacuum. However, field emission can take place from solid or liquid surfaces, into a vacuum, a fluid (e.g. air), or any non-conducting or weakly conducting dielectric. The field-induced promotion of electrons from the valence (chemistry), valence to conduction band of semiconductors (the Zener effect) can also be regarded as a form of field emission. Field emission in pure metals occurs in high electric fields: the gradients are typically higher than 1 gigavolt per metre and strongly dependent upon the work function. While electron sources based on field emission have a number of applications, field emission is most commonly an undesirable primary source of electrical breakdown, vacuum breakdown and electrical disch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles A
Charles is a masculine given name predominantly found in English and French speaking countries. It is from the French form ''Charles'' of the Proto-Germanic name (in runic alphabet) or ''*karilaz'' (in Latin alphabet), whose meaning was "free man". The Old English descendant of this word was '' Ċearl'' or ''Ċeorl'', as the name of King Cearl of Mercia, that disappeared after the Norman conquest of England. The name was notably borne by Charlemagne (Charles the Great), and was at the time Latinized as ''Karolus'' (as in ''Vita Karoli Magni''), later also as '' Carolus''. Etymology The name's etymology is a Common Germanic noun ''*karilaz'' meaning "free man", which survives in English as churl (James (wikt:Appendix:Proto-Indo-European/ǵerh₂-">ĝer-, where the ĝ is a palatal consonant, meaning "to rub; to be old; grain." An old man has been worn away and is now grey with age. In some Slavic languages, the name ''Drago (given name), Drago'' (and variants: ''Drago ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SRI International
SRI International (SRI) is a nonprofit organization, nonprofit scientific research, scientific research institute and organization headquartered in Menlo Park, California, United States. It was established in 1946 by trustees of Stanford University to serve as a center of innovation to support economic development in the region. The organization was founded as the Stanford Research Institute. SRI formally separated from Stanford University in 1970 and became known as SRI International in 1977. SRI performs client-sponsored research and development for government agencies, commercial businesses, and private foundations. It also licenses its technologies, forms strategic partnerships, sells products, and creates Research spin-off, spin-off companies. SRI's headquarters are located near the Stanford University campus. SRI's annual revenue in 2014 was approximately $540 million, which tripled from 1998 under the leadership of Curtis Carlson. In 1998, the organization was on the ver ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon Nanotube
A carbon nanotube (CNT) is a tube made of carbon with a diameter in the nanometre range ( nanoscale). They are one of the allotropes of carbon. Two broad classes of carbon nanotubes are recognized: * ''Single-walled carbon nanotubes'' (''SWCNTs'') have diameters around 0.5–2.0 nanometres, about 100,000 times smaller than the width of a human hair. They can be idealised as cutouts from a two-dimensional graphene sheet rolled up to form a hollow cylinder. * ''Multi-walled carbon nanotubes'' (''MWCNTs'') consist of nested single-wall carbon nanotubes in a nested, tube-in-tube structure. Double- and triple-walled carbon nanotubes are special cases of MWCNT. Carbon nanotubes can exhibit remarkable properties, such as exceptional tensile strength and thermal conductivity because of their nanostructure and strength of the bonds between carbon atoms. Some SWCNT structures exhibit high electrical conductivity while others are semiconductors. In addition, carbon nanotubes can b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Field Emission Display
A field-emission display (FED) is a flat panel display technology that uses large-area field electron emission sources to provide electrons that strike colored phosphor to produce a color image. In a general sense, an FED consists of a matrix of cathode-ray tubes, each tube producing a single sub-pixel, grouped in threes to form red-green-blue (RGB) pixels. FEDs combine the advantages of CRTs, namely their high contrast levels and very fast response times, with the packaging advantages of LCD and other flat-panel technologies. They also offer the possibility of requiring less power, about half that of an LCD system. FEDs can also be made transparent. Sony was the major proponent of the FED design and put considerable research and development effort into the system during the 2000s, planning mass production in 2009. Sony's FED efforts started winding down in 2009, as LCD became the dominant flat-panel technology. In January 2010, AU Optronics announced that it acquired essential FED ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Traveling-wave Tube
A traveling-wave tube (TWT, pronounced "twit") or traveling-wave tube amplifier (TWTA, pronounced "tweeta") is a specialized vacuum tube that is used in electronics to amplify radio frequency (RF) signals in the microwave range. It was invented by Andrei Haeff around 1933 as a graduate student at Caltech, and its present form was invented by Rudolf Kompfner in 1942–43. The TWT belongs to a category of "linear beam" tubes, such as the klystron, in which the radio wave is amplified by absorbing power from a beam of electrons as it passes down the tube. Although there are various types of TWT, two major categories are: *''Helix TWT'' - in which the radio waves interact with the electron beam while traveling down a wire helix which surrounds the beam. These have wide bandwidth, but output power is limited to a few hundred watts. *''Coupled cavity TWT'' - in which the radio wave interacts with the beam in a series of cavity resonators through which the beam passes. These funct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cold Cathode
A cold cathode is a cathode that is not electrically heated by a Electrical filament, filament.A negatively charged electrode emits electrons or is the positively charged terminal. For more, see field emission. A cathode may be considered "cold" if it emits more electrons than can be supplied by thermionic emission alone. It is used in Gas discharge lamp, gas-discharge lamps, such as neon lamps, discharge tubes, and some types of vacuum tube. The other type of cathode is a hot cathode, which is heated by electric current passing through a Electrical filament, filament. A cold cathode does not necessarily operate at a low temperature: it is often heated to its operating temperature by other methods, such as the current passing from the cathode into the gas. Cold-cathode devices A cold-cathode vacuum tube does not rely on external heating of an electrode to provide thermionic emission of electrons. Early cold-cathode devices included the Geissler tube and Julius Plücker, Plucker ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-ray Tubes
An X-ray tube is a vacuum tube that converts electrical input power into X-rays. The availability of this controllable source of X-rays created the field of radiography, the imaging of partly opaque objects with penetrating radiation. In contrast to other sources of ionizing radiation, X-rays are only produced as long as the X-ray tube is energized. X-ray tubes are also used in CT scanners, airport luggage scanners, X-ray crystallography, material and structure analysis, and for industrial inspection. Increasing demand for high-performance computed tomography (CT) scanning and angiography systems has driven development of very high-performance medical X-ray tubes. History X-ray tubes evolved from experimental Crookes tubes with which X-rays were first discovered on November 8, 1895, by the German physicist Wilhelm Conrad Röntgen. The first-generation ''cold cathode'' or ''Crookes'' X-ray tubes were used until the 1920s. These tubes work by ionisation of residual gas within the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermionic Cathode
In vacuum tubes and gas-filled tubes, a hot cathode or thermionic cathode is a cathode electrode which is heated to make it emit electrons due to thermionic emission. This is in contrast to a cold cathode, which does not have a heating element. The heating element is usually an electrical filament heated by a separate electric current passing through it. Hot cathodes typically achieve much higher power density than cold cathodes, emitting significantly more electrons from the same surface area. Cold cathodes rely on field electron emission or secondary electron emission from positive ion bombardment, and do not require heating. There are two types of hot cathode. In a ''directly heated cathode'', the filament is the cathode and emits the electrons. In an ''indirectly heated cathode'', the filament or ''heater'' heats a separate metal cathode electrode which emits the electrons. From the 1920s to the 1960s, a wide variety of electronic devices used hot-cathode vacuum tubes. Today, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Field Emission Display
A field-emission display (FED) is a flat panel display technology that uses large-area field electron emission sources to provide electrons that strike colored phosphor to produce a color image. In a general sense, an FED consists of a matrix of cathode-ray tubes, each tube producing a single sub-pixel, grouped in threes to form red-green-blue (RGB) pixels. FEDs combine the advantages of CRTs, namely their high contrast levels and very fast response times, with the packaging advantages of LCD and other flat-panel technologies. They also offer the possibility of requiring less power, about half that of an LCD system. FEDs can also be made transparent. Sony was the major proponent of the FED design and put considerable research and development effort into the system during the 2000s, planning mass production in 2009. Sony's FED efforts started winding down in 2009, as LCD became the dominant flat-panel technology. In January 2010, AU Optronics announced that it acquired essential FED ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Field Electron Emission
Field electron emission, also known as field-induced electron emission, field emission (FE) and electron field emission, is the emission of electrons from a material placed in an electrostatic field. The most common context is field emission from a solid surface into a vacuum. However, field emission can take place from solid or liquid surfaces, into a vacuum, a fluid (e.g. air), or any non-conducting or weakly conducting dielectric. The field-induced promotion of electrons from the valence (chemistry), valence to conduction band of semiconductors (the Zener effect) can also be regarded as a form of field emission. Field emission in pure metals occurs in high electric fields: the gradients are typically higher than 1 gigavolt per metre and strongly dependent upon the work function. While electron sources based on field emission have a number of applications, field emission is most commonly an undesirable primary source of electrical breakdown, vacuum breakdown and electrical disch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
