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Post by Son Nash on Feb 8, 2005 20:28:22 GMT -5
$3000 $4000 $600 $900
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Post by Pedro on Feb 11, 2005 19:57:08 GMT -5
EMP Bomb
Defintion:
1. The electromagnetic radiation from a nuclear explosion caused by Compton-recoil electrons and photoelectrons from photons scattered in the materials of the nuclear device or in a surrounding medium. The resulting electric and magnetic fields may couple with electrical/electronic systems to produce damaging current and voltage surges. May also be caused by nonnuclear means. 2. A broadband, high-intensity, short-duration burst of electromagnetic energy. Note: In the case of a nuclear detonation, the electromagnetic pulse consists of a continuous frequency spectrum. Most of the energy is distributed throughout the lower frequencies between 3 Hz and 30 kHz.
Physics of the EMP
An electromagnetic pulse starts with a short, intense burst of gamma rays produced from nuclear detonation. The gamma rays interact with the atoms in air molecules through a process called the Compton effect, wherein electrons are scattered at high energies, thus ionizing the atmosphere and generating a powerful electrical field. The strength of the EMP depends highly on the altitude at which it is released. At altitudes above 30,000m, it is the strongest. It is also significant at surface or low altitude bursts, but is not as effective between the two extremes.
Effects Of EMP
Although the electric field created from an EMP lasts for only a short time, its effects can be devastating. It is predicted that a single high altitude burst 200 miles above Kansas could propagate an EMP enveloping the entire United States. Electrical systems connected to things that can conduct current like wires, antennas, and metal objects will suffer significant damage. EMP effects on electronics include interference of radio frequency links, irreparable damage to microcircuits, and even the disabling of satellites. Fortunately, electronic equipment that is turned off is less likely to be damaged.
The fundamentals of the workings of an E-bomb are grounded in a basic understanding of electromagnetic physics theory. The technology relies on an electromagnetic pulse that may be conceptualized as an electric shockwave created when a stream of highly energetic photons collides with atoms of low atomic numbers to cause them to eject a 'pulse' of electrons. Such a phenomenon called the Compton effect was first observed in open-air tests of nuclear bombs when the immense detonation energy interacted with the oxygen and nitrogen atoms in the atmosphere to shoot mass quantities of electrons radially outwards from the explosion. Though these pulses diminish in strength over distance, electric lights hundreds of miles away were overloaded. Today American scientists are working diligently on the creation of E-bombs that can target artillery hells and missiles and disrupt their trajectory in mid-flight. They could be of crucial assistance in today's strategic theater that is based much more around urban warfare where one bomb could take out an enemy's electrical infrastructure before the arrival of ground troops. America's first major tests of their high-tech EMP weapons based on using high-temperature superconductors to create intense magnetic fields will take place in less than a year, however terrorists can today easily construct a potent E-bomb using 1940s technology for only $400.
This rudimentary form of E-bomb is called a flux compression generator. It consists of an explosives packed tube inside a copper coil that is energized by a bank of capacitors. This creates a magnetic field. When the explosives are detonated from rear to front, the tube flares outwards touching the copper coil and so creating a moving short circuit. This compresses the magnetic field forward and creates an EMP that surges from the ordnance with peak currents of tens of millions of amps. Such a high frequency pulse can pass through faraday cages used to ground electromagnetic energy from lightening. However, even if the cages were effective they would still be easily bypassed since any wires running from the devices within them would act as antennae and conduct the high transient voltage. There is also a so called 'late-time EMP effect.' This refers to the observations of EMPs creating localized magnetic fields within electrical systems they pass through that soon collapse sending huge surges through power and telecommunication infrastructure. This sparks a chain reaction in which all devices attached to these lines will be rendered useless by the massive surge. Such FCGs can be made with basic electrical materials, plastic explosives and readily available machine tools and can be smaller than a suitcase.
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