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Slapper Detonator
A slapper detonator, also called exploding foil initiator (EFI), is a relatively recent kind of a detonator developed by Lawrence Livermore National Laboratory, US Patent No. 4,788,913. It is an improvement of the earlier exploding-bridgewire detonator; instead of directly coupling the shock wave from the exploding wire, the expanding plasma from an explosion of a metal foil drives another thin plastic or metal foil called a "flyer" or a "slapper" across a gap, and its high-velocity impact on the explosive (for example, PETN or hexanitrostilbene) then delivers the energy and shock needed to initiate a detonation. Normally all the slapper's kinetic energy is supplied only by the heating (and hence expansion) of the plasma (the former foil) by the current passing through it, though constructions with a "back strap" to further drive the plasma forward by magnetic field exist too. This assembly is quite efficient; up to 30% of the electrical energy can be converted to the slapper's ki ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Explosive Booster
{{unreferenced, date=August 2011 An explosive booster is a sensitive explosive charge that acts as a bridge between a (relatively weak) conventional detonator and a low-sensitivity (but typically high-energy) explosive such as TNT. By itself, the initiating detonator would not deliver sufficient energy to set off the low-sensitivity charge. However, it detonates the primary charge (the booster), which then delivers an explosive shockwave that is sufficient to detonate the secondary, main, high-energy charge. Unlike C4 plastic explosive, not all explosives can be detonated simply by inserting a detonator and firing it. An initiator such as a shock tube, cannon fuse, or even a conventional detonator does not deliver sufficient shock to detonate charges comprising TNT, Composition B, ANFO and many other high explosives. Therefore, some form of "booster" is required to amplify the energy released by the detonator so that the main charge will detonate. At first, picric acid was use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triggering Sequence
A triggering sequence, also called an explosive train or a firing train, is a sequence of events that culminates in the detonation of explosives. For safety reasons, most widely used high explosives are difficult to detonate. A primary explosive of higher sensitivity is used to trigger a uniform and predictable detonation of the main body of the explosive. Although the primary explosive itself is generally a more sensitive and expensive compound, it is only used in small quantities and in relatively safely packaged forms. By design there are low explosives and high explosives made such that the low explosives are highly sensitive (i.e. their Figure of Insensitivity is low) and high explosives are comparatively insensitive. This not only affords inherent safety to the usage of explosives during handling and transport, but also necessitates an explosive triggering sequence or explosive train. The explosive triggering sequence or the explosive train essentially consists of an 'initiat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Weapon Design
Nuclear weapon designs are physical, chemical, and engineering arrangements that cause the physics package of a nuclear weapon to detonate. There are three existing basic design types: * pure fission weapons, the simplest and least technically demanding, were the first nuclear weapons built and have so far been the only type ever used in warfare (by the United States on Empire of Japan, Japan during World War II, WWII). * boosted fission weapons increase yield beyond that of the implosion design by using small quantities of fusion fuel to enhance the fission chain reaction. Boosting can more than double the weapon's fission energy yield. * thermonuclear weapon, staged thermonuclear weapons are essentially arrangements of two or more "stages", most usually two. The first stage is normally a boosted fission weapon as above (except for the earliest thermonuclear weapons, which used a pure fission weapon instead). Its detonation causes it to shine intensely with x-radiation, which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exploding-bridgewire Detonator
The exploding-bridgewire detonator (EBW, also known as exploding wire detonator) is a type of detonator used to initiate the detonation reaction in explosive materials, similar to a blasting cap because it is fired using an electric current. EBWs use a different physical mechanism than blasting caps, using more electricity delivered much more rapidly, and explode in a much more precise timing after the electric current is applied, by the process of exploding wire method. This has led to their common use in nuclear weapons. The slapper detonator is a more recent development along similar lines. History The EBW was invented by Luis Alvarez and Lawrence Johnston for the Fat Man–type bombs of the Manhattan Project, during their work in Los Alamos National Laboratory. The Fat Man Model 1773 EBW detonators used an unusual, high reliability detonator system with two EBW "horns" attached to a single booster charge, which then fired each of the 32 explosive lens units. Desc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Laser Types
This is a list of laser types, their operational wavelengths, and their applications. Thousands of kinds of laser are known, but most of them are used only for specialized research. Overview Gas lasers Chemical lasers Used as directed-energy weapons. Dye lasers Metal-vapor lasers Solid-state lasers Semiconductor lasers Other types of lasers See also *Laser construction *List of laser articles This is a list of laser topics. A * 3D printing, additive manufacturing * Abnormal reflection * Above-threshold ionization * Absorption spectroscopy * Accelerator physics * Acoustic microscopy * Acousto-optic deflector * Acousto-optic modul ... Notes Further references *Silfvast, William T. ''Laser fundamentals'', Cambridge University Press, 2004. *Weber, Marvin J. ''Handbook of laser wavelengths'', CRC Press, 1999. {{DEFAULTSORT:Laser Types ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quarry
A quarry is a type of open-pit mine in which dimension stone, rock, construction aggregate, riprap, sand, gravel, or slate is excavated from the ground. The operation of quarries is regulated in some jurisdictions to reduce their environmental impact. The word ''quarry'' can also include the underground quarrying for stone, such as Bath stone. Types of rock Types of rock extracted from quarries include: *Chalk *China clay *Cinder *Clay *Coal * Construction aggregate (sand and gravel) * Coquina * Diabase *Gabbro *Granite * Gritstone *Gypsum *Limestone *Marble *Ores *Phosphate rock *Quartz *Sandstone * Slate *Travertine Stone quarry Stone quarry is an outdated term for mining construction rocks (limestone, marble, granite, sandstone, etc.). There are open types (called quarries, or open-pit mines) and closed types ( mines and caves). For thousands of years, only hand tools had been used in quarries. In the 18th century, the use of drilling and blasting operatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mining
Mining is the extraction of valuable minerals or other geological materials from the Earth, usually from an ore body, lode, vein, seam, reef, or placer deposit. The exploitation of these deposits for raw material is based on the economic viability of investing in the equipment, labor, and energy required to extract, refine and transport the materials found at the mine to manufacturers who can use the material. Ores recovered by mining include metals, coal, oil shale, gemstones, limestone, chalk, dimension stone, rock salt, potash, gravel, and clay. Mining is required to obtain most materials that cannot be grown through agricultural processes, or feasibly created artificially in a laboratory or factory. Mining in a wider sense includes extraction of any non-renewable resource such as petroleum, natural gas, or even water. Modern mining processes involve prospecting for ore bodies, analysis of the profit potential of a proposed mine, extraction of the desired materials, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Fiber
An optical fiber, or optical fibre in Commonwealth English, is a flexible, transparent fiber made by drawing glass (silica) or plastic to a diameter slightly thicker than that of a human hair. Optical fibers are used most often as a means to transmit light between the two ends of the fiber and find wide usage in fiber-optic communications, where they permit transmission over longer distances and at higher bandwidths (data transfer rates) than electrical cables. Fibers are used instead of metal wires because signals travel along them with less loss; in addition, fibers are immune to electromagnetic interference, a problem from which metal wires suffer. Fibers are also used for illumination and imaging, and are often wrapped in bundles so they may be used to carry light into, or images out of confined spaces, as in the case of a fiberscope. Specially designed fibers are also used for a variety of other applications, some of them being fiber optic sensors and fiber lasers. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The first laser was built in 1960 by Theodore H. Maiman at Hughes Research Laboratories, based on theoretical work by Charles Hard Townes and Arthur Leonard Schawlow. A laser differs from other sources of light in that it emits light which is ''coherent''. Spatial coherence allows a laser to be focused to a tight spot, enabling applications such as laser cutting and lithography. Spatial coherence also allows a laser beam to stay narrow over great distances (collimation), enabling applications such as laser pointers and lidar (light detection and ranging). Lasers can also have high temporal coherence, which allows them to emit light with a very narrow spectrum. Alternatively, temporal coherence can be used to produce ultrashort pulses of ligh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gold
Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile metal in a pure form. Chemically, gold is a transition metal and a group 11 element. It is one of the least reactive chemical elements and is solid under standard conditions. Gold often occurs in free elemental ( native state), as nuggets or grains, in rocks, veins, and alluvial deposits. It occurs in a solid solution series with the native element silver (as electrum), naturally alloyed with other metals like copper and palladium, and mineral inclusions such as within pyrite. Less commonly, it occurs in minerals as gold compounds, often with tellurium (gold tellurides). Gold is resistant to most acids, though it does dissolve in aqua regia (a mixture of nitric acid and hydrochloric acid), forming a soluble tetrachloroaurate anion. Gold is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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