Electromagnetic Pulse Weapon - Background
Electromagnetic pulse of a nuclear explosion, a powerful short-term electromagnetic radiation in the radio frequency range caused by a nuclear explosion; one of the main damaging factors of nuclear weapons. Soviet Academician Andrei Sakharov is considered one of the pioneers in the field of electromagnetic weapons, who back in the 1950s proposed the concept of a non-nuclear bomb with an EMP. Serious research and development work in this area began in the USSR and Western countries in the 1960s.
In the early 1950s in the USSR, during the study of nuclear fusion reactions, a need arose for a device that creates very short and powerful pulses of electric current. At that time, there was already a Marx generator , which was then the only device capable of producing pulses of such high power. The prohibitive cost of the large number of capacitors used in a Marx generator prompted research into more economical designs. The first shock wave emitters were based on the ideas of Andrei Sakharov. The Explosively Pumped Flux Compression Generator [FCG] is the most mature non-nuclear technology applicable to conventional bomb designs. The FCG was first demonstrated by Clarence Fowler at Los Alamos National Laboratories (LANL) in the late 1950s. Since that time a wide range of FCG configurations has been built and tested, both in the US and the USSR. The central idea behind the construction of FCGs is that of using a fast explosive to rapidly compress a magnetic field, transferring much energy from the explosive into the magnetic field. A number of geometrical configurations for FCGs have been published. The design of one of the most effective types - with spherically symmetrical field compression - resembles the design of an implosion- type nuclear bomb. what is compressed is not a metal one (as in conventional explosive magnetic generators operating on the principle of A.D. Sakharov ), but a “virtual” liner consisting of a substance compressed and ionized by a shock wave.
Electromagnetic weapons are the latest means of warfare, designed to influence information systems. The massive use of these weapons can disrupt the functioning of the information processing infrastructure, paralyze the enemy’s military control systems and vital production facilities, which will significantly reduce its combat readiness and the effectiveness of combat operations.
Electromagnetic weapons (EMW) are a promising tool for information warfare, which was developed in the 80s and provides high efficiency in disrupting information systems. The term “information warfare” itself has come into use since the war in the Persian Gulf, during which EMP was first used in a missile version.
Experts' assessment of electromagnetic weapons as one of the most effective means of modern warfare is due to the high importance of information flows in the main areas of human activity - economic management, production, and national defense. Disruption of the functioning of the information system, which ensures constant exchange of management decisions and includes many devices for collecting and processing information, will cause serious consequences. When conducting combat operations, command, control, reconnaissance and communications systems become the targets of EMP, and the defeat of these assets will lead to the disintegration of the information system, a decrease in efficiency or a complete disruption of the operation of air defense and missile defense systems.
An electromagnetic pulse (EMP) is the result of a number of physical processes that accompany a nuclear explosion. First of all, this is the interaction of gamma and x-ray radiation with the environment surrounding a nuclear explosion, as well as the interaction of charged particles with geoelectric and geomagnetic fields, etc. This interaction leads to the formation of fast electrons, which rush in the direction of movement of gamma quanta at a speed close to speed of light. In turn, fast electrons, ionizing the medium, create slow electrons and positive ions, and the medium itself becomes electrically conductive. Due to the separation and movement of positive and negative charges, as well as due to the influence of the geomagnetic field, electric and magnetic fields of EMR arise.
During ground and low air nuclear explosions, EMP in the nearest zone is a pulse signal with a steep front and a duration of up to several tens of milliseconds. The duration of the pulse front, which determines the time of rise of the field to the maximum value, is close to the time of occurrence of nuclear processes, i.e. about 10-8s. The amplitude of the EMP can reach several hundred kilovolts per meter, and it decreases with increasing explosion height. With ground and low air explosions, the effect of EMR is observed at a distance of several kilometers from the center of the explosion, with high-altitude explosions - up to several hundred kilometers. The most important parameters of EMR include changes in the strength of electric and magnetic fields over time and their orientation in space (pulse shape), as well as the value of the maximum field strength (pulse amplitude).
The pulse has a damaging effect on objects, equipment and weapons containing electronic equipment, as well as communications and power supply systems. It disables radio-electronic systems and electrical cables at economic and infrastructure facilities, equipment and weapons, erases information in electronic data banks and disables computers. To protect objects, equipment and weapons, and personnel from EMR, the following are used: metal shielding, equipment grounding, electrical network surge suppressors, drain coils, semiconductor zener diodes, etc.
The operating principle of electromagnetic radiation is based on short-term high-power electromagnetic radiation, which can damage radio-electronic devices that form the basis of any information system. The elemental base of radio-electronic devices is very sensitive to energy overloads; a flow of electromagnetic energy of sufficiently high density can burn out semiconductor junctions, completely or partially disrupting their normal functioning. As is known, the breakdown voltages of junctions are low and range from units to tens of volts, depending on the type of device. Thus, even for silicon high-current bipolar transistors, which have increased resistance to overheating, the breakdown voltage ranges from 15 to 65 V, and for gallium arsenide devices this threshold is 10 V. Memory devices, which make up a significant part of any computer, have threshold voltages of the order of 7 V Typical logic ICs based on MOS structures range from 7 to 15 V, and microprocessors usually stop operating at voltages of 3.3–5 V.
In addition to irreversible failures, pulsed electromagnetic influence can cause recoverable failures, or paralysis of a radio-electronic device when, due to overloads, it loses sensitivity for a certain period of time. False activations of sensitive elements are also possible, which can lead, for example, to the detonation of missile warheads, bombs, artillery shells and mines.
According to the spectral characteristics, EMR can be divided into two types: low-frequency, which creates electromagnetic pulsed radiation at frequencies below 1 MHz, and high-frequency, which provides radiation in the microwave range. Both types of EMO also have differences in the methods of implementation and, to some extent, in the ways of influencing radio-electronic devices. Thus, the penetration of low-frequency electromagnetic radiation into device elements is mainly due to interference from the wired infrastructure, including telephone lines, external power cables, and information supply and retrieval cables.
The penetration paths of electromagnetic radiation in the microwave range are more extensive - they also include direct penetration into radio-electronic equipment through the antenna system, since the microwave spectrum also covers the operating frequency of the suppressed equipment. The penetration of energy through structural holes and joints depends on their size and the wavelength of the electromagnetic pulse - the strongest coupling occurs at resonant frequencies, when the geometric dimensions are commensurate with the wavelength. At waves longer than the resonant one, the coupling decreases sharply, so the impact of low-frequency EMI, which depends on interference through holes and joints in the equipment housing, is small. At frequencies above the resonant one, the decay of the coupling occurs more slowly, but due to the many types of vibrations in the volume of the equipment, sharp resonances arise.
If the flow of microwave radiation is sufficiently intense, then the air in the holes and joints is ionized and becomes a good conductor, shielding the equipment from the penetration of electromagnetic energy. Thus, an increase in the energy incident on an object can lead to a paradoxical decrease in the energy acting on the equipment and, as a consequence, to a decrease in the efficiency of EMP.
Electromagnetic weapons also have biological effects on animals and humans, mainly related to their heating. In this case, not only directly heated organs suffer, but also those that are not directly in contact with electromagnetic radiation. In the body, chromosomal and genetic changes, activation and deactivation of viruses, changes in immunological and even behavioral reactions are possible. A rise in body temperature of 1°C is considered dangerous, and continued exposure in this case can lead to death.
The most effective protection against EMF is, of course, preventing its delivery by physically destroying the carriers, as in protection against nuclear weapons. However, this is not always achievable, so one should also resort to electromagnetic protection measures for the radio-electronic equipment itself. Such measures, obviously, should first of all include complete shielding of the equipment itself, as well as the premises in which it is located.
It is known that if the room is likened to a Faraday cage, preventing the penetration of an external electromagnetic field, then the equipment’s protection from EMF will be fully ensured. However, in reality, such shielding is impossible, since the equipment requires external power supply and communication channels for receiving and transmitting information. The communication channels themselves must also be protected from the penetration of electromagnetic influences through them to the equipment. Installing filters in this case does not help, since they work only in a certain frequency band and are adjusted accordingly, and filters designed to protect against low-frequency EMI will not protect against high-frequency EMI and vice versa.
Good protection against electromagnetic interference via communication channels can be provided by fiber-optic lines used instead, but this cannot be done for power circuits. The problem of protection against electromagnetic radiation is further aggravated by the fact that the development of modern information systems is moving along the path of their disintegration. Instead of large centers for receiving and processing information, each institution prefers to have its own computer networks using telephone lines. This increases the vulnerability of electronic equipment in relation to EMP, as a result of which the use of EMP in military conflicts becomes even more feasible and feasible.
Considering the effectiveness and prospects of using EMP in military operations, as well as the advantages of those who own this type of weapon, most developments of EMP are kept in the strictest confidence under a heading more retrictiver than “Top Secret”, and most problems are discussed only in closed meetings.
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