|
Vircator
A vircator (VIRtual CAthode oscillaTOR) is a microwave generator that is capable of generating brief pulses of tunable, narrow band microwaves at very high power levels. Its application is mainly in the area of electronic warfare, by way of interfering with electronic equipment such as radars or radio equipment. A typical vircator is built inside an evacuated resonant cavity or waveguide. An electrode, a cold cathode, at one end injects an intense electron beam, such as from a Marx generator or a flux compression generator, optionally with a suitable pulse forming network, e.g. a Blumlein. The pulse has magnitude in the range of hundred or more kilovolts and duration of about 50-150 nanoseconds. The electrons are attracted to a thin anode, such as an aluminized PET film or a stainless steel mesh, that is connected to the grounded waveguide body. The unit is surrounded by a magnet. Due to the intensity of the electron beam, many electrons pass through the anode into the region b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VIRCATOR
A vircator (VIRtual CAthode oscillaTOR) is a microwave generator that is capable of generating brief pulses of tunable, narrow band microwaves at very high power levels. Its application is mainly in the area of electronic warfare, by way of interfering with electronic equipment such as radars or radio equipment. A typical vircator is built inside an evacuated resonant cavity or waveguide. An electrode, a cold cathode, at one end injects an intense electron beam, such as from a Marx generator or a flux compression generator, optionally with a suitable pulse forming network, e.g. a Blumlein. The pulse has magnitude in the range of hundred or more kilovolts and duration of about 50-150 nanoseconds. The electrons are attracted to a thin anode, such as an aluminized PET film or a stainless steel mesh, that is connected to the grounded waveguide body. The unit is surrounded by a magnet. Due to the intensity of the electron beam, many electrons pass through the anode into the region b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electromagnetic Pulse
An electromagnetic pulse (EMP), also a transient electromagnetic disturbance (TED), is a brief burst of electromagnetic energy. Depending upon the source, the origin of an EMP can be natural or artificial, and can occur as an electromagnetic field, as an electric field, as a magnetic field, or as a conducted electric current. The electromagnetic interference caused by an EMP disrupts communications and damages electronic equipment; at higher levels of energy, an EMP such as a lightning strike can physically damage objects such as buildings and aircraft. The management of EMP effects is a branch of electromagnetic compatibility (EMC) engineering. EMP weapons are designed to deliver the damaging effects of a high-energy EMP that will disrupt unprotected infrastructure in the country, thus the employment of an EMP weapon against a country is the scenario of war most likely to collapse the functionality of the electrical network of the country. General characteristics An electrom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microwave
Microwave is a form of electromagnetic radiation with wavelengths ranging from about one meter to one millimeter corresponding to frequencies between 300 MHz and 300 GHz respectively. Different sources define different frequency ranges as microwaves; the above broad definition includes both UHF and EHF (millimeter wave) bands. A more common definition in radio-frequency engineering is the range between 1 and 100 GHz (wavelengths between 0.3 m and 3 mm). In all cases, microwaves include the entire SHF band (3 to 30 GHz, or 10 to 1 cm) at minimum. Frequencies in the microwave range are often referred to by their IEEE radar band designations: S, C, X, Ku, K, or Ka band, or by similar NATO or EU designations. The prefix ' in ''microwave'' is not meant to suggest a wavelength in the micrometer range. Rather, it indicates that microwaves are "small" (having shorter wavelengths), compared to the radio waves used prior to microwave te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Energy Weapons , fictional shield-type energy weapons
{{Disambiguation ...
Energy weapon may refer to: *Directed-energy weapon, real-life energy weapons used in the military **Raygun, fictional gun-type energy weapons *Energy sword, fictional sword-type energy weapons *Force field (technology) In speculative fiction, a force field, sometimes known as an energy shield, force shield, energy bubble or deflector shield, is a barrier made of things like energy, negative energy, dark energy, electromagnetic fields, gravitational fields, el ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Field Electron Emission
Field electron emission, also known as field emission (FE) and electron field emission, is emission of electrons induced by 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. The terminology is historical because related phenomena of surface photoeffect, thermionic emission (or Richardson–Dushman effect) and "cold electronic emission", i.e. the emission of electrons in strong static (or quasi-static) electric fields, were discovered and studied independently from the 1880s to 1930s. When field emission is used without qualifiers it typically means "cold emission". Field emission in pure metal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-ray
An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz ( to ) and energies in the range 145 eV to 124 keV. X-ray wavelengths are shorter than those of UV rays and typically longer than those of gamma rays. In many languages, X-radiation is referred to as Röntgen radiation, after the German scientist Wilhelm Conrad Röntgen, who discovered it on November 8, 1895. He named it ''X-radiation'' to signify an unknown type of radiation.Novelline, Robert (1997). ''Squire's Fundamentals of Radiology''. Harvard University Press. 5th edition. . Spellings of ''X-ray(s)'' in English include the variants ''x-ray(s)'', ''xray(s)'', and ''X ray(s)''. The most familiar use of X-rays is checking for fractures (broken bones), but X-rays are also used in other ways. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Space Charge
Space charge is an interpretation of a collection of electric charges in which excess electric charge is treated as a continuum of charge distributed over a region of space (either a volume or an area) rather than distinct point-like charges. This model typically applies when charge carriers have been emitted from some region of a solid—the cloud of emitted carriers can form a space charge region if they are sufficiently spread out, or the charged atoms or molecules left behind in the solid can form a space charge region. Space charge only occurs in dielectric media (including vacuum) because in a conductive medium the charge tends to be rapidly neutralized or screened. The sign of the space charge can be either negative or positive. This situation is perhaps most familiar in the area near a metal object when it is heated to incandescence in a vacuum. This effect was first observed by Thomas Edison in light bulb filaments, where it is sometimes called the Edison effect. Space c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cathode
A cathode is the electrode from which a conventional current leaves a polarized electrical device. This definition can be recalled by using the mnemonic ''CCD'' for ''Cathode Current Departs''. A conventional current describes the direction in which positive charges move. Electrons have a negative electrical charge, so the movement of electrons is opposite to that of the conventional current flow. Consequently, the mnemonic ''cathode current departs'' also means that electrons flow ''into'' the device's cathode from the external circuit. For example, the end of a household battery marked with a + (plus) is the cathode. The electrode through which conventional current flows the other way, into the device, is termed an anode. Charge flow Conventional current flows from cathode to anode outside of the cell or device (with electrons moving in the opposite direction), regardless of the cell or device type and operating mode. Cathode polarity with respect to the anode can be positive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnet
A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, steel, nickel, cobalt, etc. and attracts or repels other magnets. A permanent magnet is an object made from a material that is magnetized and creates its own persistent magnetic field. An everyday example is a refrigerator magnet used to hold notes on a refrigerator door. Materials that can be magnetized, which are also the ones that are strongly attracted to a magnet, are called ferromagnetic (or ferrimagnetic). These include the elements iron, nickel and cobalt and their alloys, some alloys of rare-earth metals, and some naturally occurring minerals such as lodestone. Although ferromagnetic (and ferrimagnetic) materials are the only ones attracted to a magnet strongly enough to be commonly considered magnetic, all other substances respond weakly to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stainless Steel
Stainless steel is an alloy of iron that is resistant to rusting and corrosion. It contains at least 11% chromium and may contain elements such as carbon, other nonmetals and metals to obtain other desired properties. Stainless steel's corrosion resistance, resistance to corrosion results from the chromium, which forms a Passivation (chemistry), passive film that can protect the material and self-healing material, self-heal in the presence of oxygen. The alloy's properties, such as luster and resistance to corrosion, are useful in many applications. Stainless steel can be rolled into Sheet metal, sheets, plates, bars, wire, and tubing. These can be used in cookware, cutlery, surgical instruments, major appliances, vehicles, construction material in large buildings, industrial equipment (e.g., in paper mills, chemical plants, water treatment), and storage tanks and tankers for chemicals and food products. The biological cleanability of stainless steel is superior to both alumi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anode
An anode is an electrode of a polarized electrical device through which conventional current enters the device. This contrasts with a cathode, an electrode of the device through which conventional current leaves the device. A common mnemonic is ACID, for "anode current into device". The direction of conventional current (the flow of positive charges) in a circuit is opposite to the direction of electron flow, so (negatively charged) electrons flow out the anode of a galvanic cell, into an outside or external circuit connected to the cell. For example, the end of a household battery marked with a "-" (minus) is the anode. In both a galvanic cell and an electrolytic cell, the anode is the electrode at which the oxidation reaction occurs. In a galvanic cell the anode is the wire or plate having excess negative charge as a result of the oxidation reaction. In an electrolytic cell, the anode is the wire or plate upon which excess positive charge is imposed. As a result of this, anion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
