A nuclear electromagnetic pulse (commonly abbreviated as nuclear EMP, or NEMP) is an explosion of electromagnetic radiation created by nuclear explosions. The rapidly changing electric and magnetic fields can pair with electrical and electronic systems to produce damaging currents and voltages. The specific characteristics of each particular nuclear EMP event vary according to a number of factors, the most important being the height of the detonation.
The term "electromagnetic pulse" generally does not include the optical range (infrared, visible, ultraviolet) and ionizing (such as X-rays and gamma radiation). In military terminology, nuclear warheads detonated tens to hundreds of kilometers above the earth's surface are known as high-altitude electromagnetic pulse (HEMP) devices. The effects of HEMP devices depend on factors including detonation height, energy yield, gamma ray output, interaction with the Earth's magnetic field and the electromagnetic shield of the target.
Video Nuclear electromagnetic pulse
History
The fact that the electromagnetic pulses generated by nuclear explosions are known in the early days of nuclear weapons testing. The magnitude of the EMP and its effect significance, however, are not immediately realized.
During the first United States nuclear test on July 16, 1945, electronic equipment was shielded because Enrico Fermi was expecting an electromagnetic pulse. The official technical history for the first nuclear test stated, "All signal lines are completely protected, in many cases double protected, in spite of these many records lost due to fake pickup at the time of the explosion that paralyzed the recording equipment." During the British nuclear test in 1952-1953 the failure of instrumentation was associated with "radioflash", which is their term for EMP.
The first openly publicized observations about unique aspects of nuclear heights of EMP occurred during the helium lofted balloon of the Yucca nuclear test of the Hardtack I series on April 28, 1958. In that test, the measurement of the electric field from a 1.7 kiloton weapon went from the scale of the test instrument and is estimated to be about 5 times the oscilloscope limit. The Yucca EMP is initially positive while the low altitude bursts are negative pulses. Also, the polarization of the Yucca EMP signal is horizontal, while the low-altitude nuclear EMP is vertically polarized. Despite these differences, the unique EMP results are dismissed as a possible wave propagation anomaly.
The nuclear test at altitude in 1962, as discussed below, confirms the unique results of Yucca's high-altitude test and raises awareness of highland nuclear EMP beyond the original group of defense scientists. A larger scientific community became aware of the importance of the EMP problem after a series of three articles on nuclear EMP published in 1981 by William J. Broad in Science.
Starfish Prime
In July 1962, the US tested Starfish Prime, detonating a 1.44 megaton 400 kilometer (250 million) bomb above the Pacific Ocean. This shows that the effects of nuclear explosions at altitudes are much greater than those previously calculated. Starfish Prime creates a public-known effect by causing electrical damage in Hawaii, about 1,445 kilometers (898 miles) from the point of explosion, crashing about 300 streetlights, turning on multiple burglar alarms and damaging microwave connections.
Starfish Prime was the first success in a series of nuclear tests in the United States in 1962 known as Operation Fishbowl. The next test collects more data on high altitude EMP phenomena.
The high-level nuclear tests of Bluegill Triple Prime and Kingfish in October and November 1962 in Operation Fishbowl provided fairly clear data to enable physicists to accurately identify the physical mechanisms behind electromagnetic pulses.
The EMP damage from the Starfish Prime test was quickly remedied because, in part, with the fact that EMP in Hawaii is relatively weak compared to what can be produced with a more intense pulse, and partly because of the relative roughness (compared to today) of Hawaii's electrical and electronic infrastructure at year 1962.
The relatively small extent of EMP Starfish Prime in Hawaii (about 5.6 kilovolt/meter) and the relatively small amount of damage (eg, only 1 to 3 percent of street lights went out) led some scientists to believe, in the early days of EMP research, that the problem may not be significant. Subsequent calculations show that if the Starfish Prime warhead has been detonated over the northern United States continent, the magnitude of the EMP will be much larger (22 to 30 kV/m) due to the greater force of the Earth's magnetic field over the United States. Country, as well as different orientations at high latitude. This calculation, combined with an increasingly rapid dependence on EMP-sensitive microelectronics, increased awareness that EMP can be a significant problem.
Soviet Test 184
In 1962, the Soviet Union also conducted three nuclear tests that produced EMP in space over Kazakhstan, the last in "Soviet K nuclear test". Although these weapons are much smaller (300 kilotons) than Starfish Prime tests, they are more than one population, large land and in locations where the Earth's magnetic field is larger; the damage caused by the resulting EMP is reported to be much larger than in Starfish Prime. E3 waves such as the geomagnetic storm of Test 184 induce a surge of currents in long underground electrical conduits that cause fires at power plants in the city of Karaganda.
After the collapse of the Soviet Union, this level of damage was communicated informally to US scientists. For several years US and Russian scientists collaborated on the HEMP phenomenon. Funding is guaranteed to allow Russian scientists to report on some Soviet EMP results in international scientific journals. As a result, formal documentation of some of the EMP damage in Kazakhstan exists but is still uncommon in open scientific literature.
For one of the Project K tests, Soviet scientists instructed a telephone line of 570 kilometers (350 mi) in an area they expected to be affected by the pulse rate. The monitored telephone line is divided into 40 to 80 kilometers (25 to 50 mi) long sub-lines, separated by repeaters. Each sub-line is protected by a fuse and by a more full voltage gas shield. The EMP of the October 22 nuclear test (K-3) (also known as Test 184) blew out all the fuses and fired all the voltage protectors on all sub-lines.
The published report, including the IEEE 1998 article, has stated that there is a significant problem with the ceramic insulators in the above power line during the test. A 2010 technical report written for Oak Ridge National Laboratory states that "The electrical conduit insulator is damaged, resulting in a short circuit on the line and several lines that separate from the poles and fall to the ground."
Maps Nuclear electromagnetic pulse
Characteristics
Nuclear EMP is a complex multi-pulse, usually described in three components, as defined by the International Electrotechnical Commission (IEC).
Three components of nuclear EMP, as defined by IEC, are called "E1", "E2" and "E3".
E1
E1 pulse is a very fast component of nuclear EMP. E1 is a short but intense electromagnetic field that induces a high voltage in an electrical conductor. E1 causes most of the damage by causing the voltage to be exceeded. E1 can destroy computers and communications equipment and it changes too quickly (nanoseconds) for ordinary surge protectors to provide effective protection from it. Fast-acting surge protectors (such as those using TVS diodes) will block E1 pulses.
E1 is generated when gamma radiation from nuclear detonation ionizes (electron strip of) atoms in the upper atmosphere. This is known as the Compton effect and the resulting current is called "Compton current". Electrons run in a direction that generally leads downwards at a relativistic speed (over 90 percent the speed of light). In the absence of a magnetic field, this will produce large radial pulses of electric current spreading out from the limited explosion site at the source region (the region where the gamma photon is attenuated). The Earth's magnetic field gives force to the flow of electrons at right angles to the field and the original vector of the particle, which deflects the electrons and leads to the synchrotron radiation. As the outgoing gamma pulse moves to spread at the speed of light, synchrotron radiation from Compton electrons adds coherently, leading to electromagnetic signals radiated. This interaction produces a large and short pulse.
Some physicists work on the problem of identifying the pulse mechanism of HEMP E1. This mechanism was eventually identified by Conrad Longmire of Los Alamos National Laboratory in 1963.
Longmire provides numerical values ​​for typical cases of E1 pulses generated by second generation nuclear weapons such as Operation Fishbowl. The typical gamma rays released by the weapon have an energy of about 2 MeV (mega-electron volts). Gamma rays transfer about half their energy to free electrons, giving about 1 MeV of energy.
In a vacuum and no magnetic field, the electrons will travel with a current density of tens of amperes per square meter. Due to the downward slope of the Earth's magnetic field at high latitudes, the peak field strength region is the U-shaped region to the equatorial side of the detonation. As shown in the diagram, for a nuclear explosion in the northern hemisphere, this U-shaped region is to the south of the detonation point. Near the equator, where the Earth's magnetic field is closer to horizontal, the field strength of E1 is closer symmetrical around the site of the explosion.
At the strength of a typical geomagnetic field of middle latitudes, these early electrons surround a magnetic field line with a radius of about 85 meters (about 280 feet). These initial electrons are stopped by a collision with an air molecule at an average distance of about 170 meters (less than 580 feet). This means that most of the electrons are stopped by a collision with an air molecule before completing a full spiral around the field line.
The interaction of negatively charged electrons with this magnetic field emits a pulse of electromagnetic energy. The pulses usually rise to their peak value in some 5 nanoseconds. The magnitude usually decays in half in 200 nanoseconds. (With the IEC definition, this E1 pulse ends 1000 nanoseconds after it begins.) This process occurs simultaneously in about 10 electron 25. The simultaneous action of the electrons causes the resulting pulses of each electron to emit coherently, adding to produce a single large amplitude, but narrow, radiated pulses.
Secondary collisions cause the next electron to lose energy before it reaches the ground level. The electrons generated by these collisions have less energy so they do not contribute significantly to the E1 pulse.
This 2 MeV gamma ray usually produces E1 pulses near the ground at a fairly high latitude of about 50,000 volts per meter. The ionization process in the mid-stratosphere causes this region to be an electrical conductor, a process that inhibits the production of further electromagnetic signals and causes field strength to saturate about 50,000 volts per meter. The strength of the E1 pulse depends on the amount and intensity of the gamma rays and at the speed of the gamma ray burst. Strength also depends somewhat on altitude.
There are reports of "super-EMP" nuclear weapons capable of exceeding the 50,000 volts per meter limit with unspecified mechanisms. The facts and details of possible construction of these weapons are classified and, therefore, not confirmed in the open scientific literature
E2
The E2 component is generated by scattered gamma rays and inelastic gammas produced by neutrons. This E2 component is a "time between" pulses which, by IEC definition, lasts from about 1 microsecond to 1 second after the explosion. E2 has much in common with lightning, though E2 induced by lightning may be much larger than nuclear E2. Due to the similarity and widespread use of lightning protection technology, E2 is generally regarded as the easiest to protect.
According to the United States EMP Commission, the main problem with E2 is that it immediately follows E1, which may have damaged devices that would normally protect against E2.
The 2004 EMP Commission Executive Report stated, "In general, it will not be a problem for critical infrastructure systems because they have existing protective measures for defense against occasional lightning attacks.The most significant risk is synergistic, since the E2 component follows a fraction of a second after the first component contempt, which has the ability to damage or destroy many protective and control features The energy associated with the second component can thus be allowed to enter into and damage the system. "
E3
The E3 component differs from E1 and E2. E3 is a much slower pulse, up to tens to hundreds of seconds. This is due to the transient nuclear distortion of the Earth's magnetic field. The E3 component has similarities to geomagnetic storms caused by solar flares. Like a geomagnetic storm, E3 can generate a geomagnetic induced current on a long electrical conductor, damaging components such as an electrical power transformer.
Because of the similarity between the solar and nuclear-driven geomagnetic storms of E3, it has become common to refer to solar-induced solar storms as "solar EMPs". "Solar EMP," does not include E1 or E2 components.
Generation
Factors that control the effectiveness of weapons include altitude, yield, construction details, target distance, geographical features of intervention, and local forces of the Earth's magnetic field.
Altitude of weapons
According to an internet primer published by the Federation of American Scientists
- High-altitude nuclear detonation produces direct flux of gamma rays from nuclear reactions inside the device. These photons in turn produce high-energy free electrons by compton scattering at altitudes between (about) 20 and 40 km. These electrons are then trapped in the Earth's magnetic field, causing an oscillating electric current. This current is asymmetrical in general and gives rise to a rapidly radiating electromagnetic field called the electromagnetic pulse (EMP). Because the electrons are trapped essentially simultaneously, a very large electromagnetic source radiates coherently.
- Pulses can easily reach continental-sized areas, and this radiation can affect systems on land, sea and air.... A large detonated device at 400-500 km (250 to 312 miles) above Kansas will affect the entire continent of the United States. Signals from such events extend to the visual horizon as seen from the point of explosion .
So, for the equipment to be affected, the weapon must be above the visual horizon.
The altitude shown above is larger than the International Space Station and many low Earth orbit satellites. Large guns can have a dramatic impact on satellite and communications operations as happened during Operation Fishbowl. The damaging effects on orbiting satellites are usually due to factors other than EMP. In Starfish Prime nuclear tests, most of the damage occurs to satellite solar panels when it passes the radiation belt created by the explosion.
For detonation in the atmosphere, the situation is more complex. In the range of gamma-ray deposition, simple law is no longer applicable because of ionized air and other EMP effects, such as radial electric fields due to the separation of Compton electrons from air molecules, together with other complex phenomena. For surface bursts, the absorption of gamma rays by air limits the range of gamma-ray deposition to about 10 miles, whereas for low-density airborne explosions at high altitudes, the settling range will be much greater.
The arms result
The results of nuclear weapons commonly used during Cold War planning for EMP attacks are in the range of 1 to 10 megatons. This is approximately 50 to 500 times the size of the Hiroshima and Nagasaki bombs. Physicists have testified at a US Congressional hearing that weapons with 10 kilotons or less can produce large EMPs.
EMP at a fixed distance from the explosion increases at most as the square root of the result (see illustration on the right). This means that even though the 10 kiloton weapon has only 0.7% energy release from the 1.44-megaton Starfish Prime test, the EMP will be at least 8% as strong. Since the E1 component of nuclear EMP relies on rapid gamma ray output, which is only 0.1% of the yield in Starfish Prime but can be 0.5% of the yield in a low yield pure nuclear fission weapon, 10 kilotons of bomb can easily be 5 x 8 % = 40% as strong as Starfish Prime 1.44 megatons when producing EMP.
The total rapid gamma-ray energy in a fission explosion is 3.5% of the yield, but in 10-kiloton detonations that trigger explosions around the bomb core absorb about 85% of the fast gamma rays, so the output is only about 0.5% of the yield. In Starfish Prime thermonuclear, the fission product is less than 100% and the thick outer layer absorbs about 95% of the rapid gamma rays from the thrusters around the fusion stage. Thermonuclear weapons are also less efficient at generating EMP because the first stage can ionize the air which is conductive and therefore rapidly out of the Compton current generated by the fusion stage. Therefore, small pure fission weapons with thin cases are much more efficient in causing EMP than most megaton bombs.
This analysis, however, only applies to fast E1 and E2 components of nuclear EMP. The E3 component that resembles a geomagnetic storm from a nuclear EMP is more proportionate to the total energy output of the weapon.
Target distance
In nuclear EMP all the components of the electromagnetic pulse are generated outside the weapon.
For nuclear explosions at high altitudes, most of the EMP is produced away from detonation (where gamma radiation from the explosion hit the upper atmosphere). The electric field of the EMP is very uniform over the large area affected.
According to the standard reference text on the effects of nuclear weapons published by the US Department of Defense, "The peak electric field (and its amplitude) on the Earth's surface from high altitude eruptions will depend on explosion results, altitude altitude, observer location, and orientation with respect to geomagnetic fields. the general rule, however, the field strength can be estimated to be tens of kilovolts per meter in most areas that receive EMP radiation. "
This text also states that, "... in most areas affected by EMP, the strength of the electric field in the ground will exceed 0.5 E max . of a few hundred kilotons, this is not always true because the field strength in the Earth tangent line can be much smaller than 0.5 E max . "
( E max refers to the maximum electric field strength in the affected area.)
In other words, the strength of the electric field across an area affected by the EMP will be quite uniform for weapons with large gamma-ray output. For smaller weapons, electric fields can fall faster with increasing distance.
Effects
Energetic EMPs can temporarily disrupt or permanently damage electronic equipment by generating high voltage and high current currents; semiconductor component is very risky. Damage effects can range from invisible to the eye, until the device is completely scattered. The cable, although short, can serve as an antenna to transmit pulse energy to the equipment.
Vacuum tubes vs solid state electronics
Older appliances, vacuum tubes (valves) are generally much more susceptible to nuclear EMP than solid state equipment, which is much more susceptible to damage by large, short voltage and current spikes. Soviet-era Cold War military aircraft often have avionics based on vacuum tubes due to limited solid-state capabilities and vacuum tube equipment believed to be more likely to survive.
Other components in the vacuum tube circuit can be damaged by EMP. The vacuum tube equipment was damaged in 1962 testing. The solid 2-way FMC PRC-77 VHF station survives through extensive EMP testing. The previous PRC-25, almost identical except for the final amplification stage of the vacuum tube, was tested in the EMP simulator, but not certified to remain fully functional.
Electronic in vs. operation. inactive
Tools that are running at a time when EMP is more vulnerable. Even low-energy pulses have access to a power source, and all parts of the system are illuminated by pulses. For example, high-loop currents can be created throughout the power supply, burning multiple devices along the path. Such effects are unpredictable, and require testing to assess potential vulnerabilities.
On the airplane
Many nuclear explosions occur using air bombs. The B-29 aircraft delivering nuclear weapons in Hiroshima and Nagasaki do not lose power from electrical damage, because electrons (released from the air by gamma rays) are stopped quickly in normal air for bursts below about 10 kilometers (6.2 miles), so they are not significantly deflected by the Earth's magnetic field.
If the aircraft carrying Hiroshima and Nagasaki bombs are in a zone of strong nuclear radiation when bombs explode over the cities, they will suffer the effects of EMP's radial separation. But this only happens in a severe blast radius for detonation below about 10 km altitude.
During Fishbowl Operation, EMP disturbance was suffered by a KC-135 photography plane that flew 300 km (190 mi) from 410 kt (1,700 TJ) explosion at explosive altitude 48 and 95 km (30 and 59 mi). Electronic vital less sophisticated than today and the plane can land safely.
On car
An EMP probably will not affect most cars, although modern cars use a lot of electronics, because electronic circuits and cable cars may be too short to be affected. In addition, the car's metallic frame provides protection. However, even a small number of cars striking due to electronic damage will cause temporary traffic congestion.
In small electronics
EMP has a smaller effect the shorter the length of the electrical conductor; although other factors also affect electronic vulnerability, so no cutting limit determines whether some equipment will survive. However, small electronic devices, such as watches and cell phones, are likely to withstand EMP.
In humans and animals
Although the voltage can accumulate in the electrical conductor after the EMP, but generally will not flow out into the human or animal body, and thus the contact is safe.
Post-Cold War attack scenario
The United States EMP Commission was formed by the United States Congress in 2001. The Commission is officially known as the Commission for Assessing Threats to the United States from Electromagnetic Wave Attacks (EMP).
The Commission gathered renowned scientists and technologists to compile several reports. In 2008, the Commission released the "Critical National Infrastructure Report". This report explains the possible consequences of a nuclear EMP on civil infrastructure. Although this report covers the United States, most of the information applies to other industrialized countries. The 2008 report is a follow-up to the more general report issued by the commission in 2004.
In a written testimony submitted to the US Senate in 2005, an EMP Commission staff member reported:
The EMP Commission sponsors a worldwide survey of foreign scientific and military literature to evaluate knowledge, and possibly intent, foreign countries in connection with electromagnetic pulse (EMP) attacks. The survey found that the physics of EMP phenomena and the military potential of EMP attacks are widely understood in the international community, as reflected in official and unofficial papers and statements. An open-source survey over the past decade found that knowledge of EMP and EMP attacks is evident at least in Britain, France, Germany, Israel, Egypt, Taiwan, Sweden, Cuba, India, Pakistan, Iraq under Saddam Hussein, Iran, North Korea, China and Russia.
Many foreign analysts - particularly in Iran, North Korea, China and Russia - see the United States as a potential aggressor who will be willing to use all of his weapons, including nuclear weapons, in the first attack. They assume the United States has a contingency plan to create a nuclear EMP attack, and is willing to implement the plan in various situations.
Russian and Chinese military scientists in open source writings describe the basic principles of nuclear weapons specially designed to produce enhanced EMP effects, which they call "Super-EMP" weapons. Super-EMP weapons, according to these foreign open-source writings, could destroy even US civilian civilian military and civilian systems.
The US EMP Commission determined that the old protection was almost completely absent in the civil infrastructure of the United States and that most US military services were less protected against EMP than during the Cold War. In a public statement, the Commission recommends making electronic equipment and electrical components resistant to EMP - and maintaining a spare parts inventory that will enable immediate repair. The United States EMP Commission does not see any other country.
In 2011 the Council of Defense Science published a report on ongoing efforts to maintain a critical military and civilian system against EMP and other nuclear weapons effects.
The US military service was developed, and in some cases published, hypothetical EMP attack scenarios.
In 2016, Los Alamos Laboratory started phase 0 of a multi-year (up to phase 3) study to investigate an EMP that prepared a strategy to follow for the rest of the study.
In 2017 the US Department of Energy publishes "DOE Electromagnetic Energy Security Action Plan", Edwin Boston publishes a dissertation on the topic and the EMP Commission publishes "Assessing the threats of electromagnetic pulse (EMP)". The EMP Commission closed in the summer of 2017. They found that previous reports had underestimated the impact of EMP attacks on national infrastructure and highlighted problems with communications from the Department of Defense due to the confidential nature of the material and recommended that DHS instead go to the DOE for guidance and direction should cooperate immediately with a more knowledgeable section of DOE. Some reports are in the process of being released to the general public.
Protect infrastructure
The problem of protecting the civil infrastructure from electromagnetic pulses has been studied intensively throughout the EU, and in particular by the UK.
By 2017, several electric utility companies in the United States have been involved in a three-year research program on the impact of HEMP to the US electricity grid led by the nonprofit industry organization Electric Power Research Institute (EPRI).
In popular fiction and culture
Especially since the 1980s, Nuclear EMP weapons have gained a significant presence in fiction and popular culture.
Popular media often portray the effects of EMP incorrectly, causing misunderstandings among the public and even professionals, and official efforts have been made in the United States to set the record straight. The US Space Command assigns science teacher Bill Nye to produce a video called "Hollywood vs. EMP" so that inaccurate Hollywood fiction will not confuse those who have to deal with actual EMP events. This video is not available to the general public.
See also
References
Source
- This article incorporates public domain material from the "Federal Standard 1037C" Public Service Administration document (to support MIL-STD-188).
- Vladimir Gurevich "Cyber ​​Threats and Electromagnetism in Modern Relay Protection" - CRC Press (Taylor & Francis Group), Boca Raton - New York - London, 2014, 222 p.
- Vladimir Gurevich "Protection of Substation Critical Equipment Against Intentional Electromagnetic Threat" - Wiley, London, 2016, 300 p.
Further reading
- COMMISSION FOR ASSESSING THREATS TO THE UNITED STATES OF ELECTROMAGNETIC PULSE (EMP) ATTACK (July 2017). "Assessing the Threats of an EMP Attack - Executive Report" (PDF) . www.dtic.mil .
- ISBNÃ, 978-1-59-248389-1 21st Century Complete Guide to Electromagnetic Pulse (EMP) Attacks Threats, Commission Report to Assess Threats to the United States from Electromagnetic... High Altitude Nuclear Weapon EMP Attack (CD -ROM)
- ISBNÃ, 978-0-16-056127-6 Threats arising from electromagnetic pulses (EMP) for military systems and civil infrastructure US: Hearing before Military Research and Development Subcommittee - first session, hearing held July 16, 1997 ( Unknown Binding)
- ISBNÃ, 978-0-471-01403-4 Radiation Pulses Electric and Protective Techniques
- ISBNÃ, 978-0-16-080927-9 Commission Report to Assess Threat to the United States from Electromagnetic Pulse (EMP) Attack
External links
- Glasstone, Samuel; Dolan, Philip J. (1977). "Nuclear Weapon Effect". United States Department of Defense. Archived from original on 2009-08-21 Ã,
- GlobalSecurity.org - Electromagnetic Pulses: From chaos to manageable solutions
- Electromagnetic Pulse (EMP) and Tempest Protection Means - US Army Corps of Engineers
- The EMP data from the Starfish nuclear test as measured by Richard Wakefield of LANL, and review of evidence related to the effects as far as 1,300 km away in Hawaii, as well as the Russian EMP test review of 1962
- Read the Congressional Research Service Report (CRS) on HEMP
- MIL-STD-188-125-1
- How E-Bomb Works
- The Commission to Assess Threats to the United States from Electromagnetic Pulse Attacks (EMP)
- NEMP and Nuclear Plant
Source of the article : Wikipedia
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