Electromagnetic pulse how does it work

Also, some observers argue that unless the United States openly describes how it is taking action to reduce EMP vulnerabilities within critical infrastructures, perceived inaction will increase the likelihood that a rogue nation will seek to employ the asymmetric effects of HEMP against our computer systems. The EMP commission was reestablished by P. The new Commission to Assess the Threat to the United States from Electromagnetic Pulse Attack note that the new title no longer includes the phrase "High Altitude", and adds the new word "Attack" continues with the same membership, and the Secretary of Defense is authorized to appoint a new member in the event of a vacancy.

On July 22, , members of the EMP commission testified before the House Armed Services Committee and presented a report consisting of the following five volumes:. The report stated that High Altitude EMP is capable of causing catastrophic consequences for the nation, and that the current vulnerability of our critical infrastructures, which depend so heavily on computers and electronics, can both invite and reward attack if not corrected. EMP test facilities have been mothballed or dismantled, and research concerning EMP phenomena, hardening design, testing, and maintenance has been substantially decreased.

However, the emerging threat environment, characterized by a wide spectrum of actors that include near-peers, established nuclear powers, rogue nations, sub-national groups, and terrorist organizations that either now have access to nuclear weapons and ballistic missiles or may have such access over the next 15 years have [sic] combined to place the risk of EMP attack and adverse consequences on the U. Our increasing dependence on advanced electronics systems results in the potential for an increased EMP vulnerability of our technologically advanced forces, and if unaddressed makes EMP employment by an adversary an attractive asymmetric option.

The EMP commission's report proposed a five-year plan for protecting critical infrastructures from EMP and from other large-scale terrorist attacks. The five-year plan is briefly summarized in Volume 3 of the report. However, some portions of the five-year plan that are related to military equipment may remain classified. The Commission is currently preparing a review of the DOD response to recommendations made in Findings showed that only limited EMP vulnerability testing had previously been done for modern electronic systems that help support these infrastructures.

In addition, the Commission expressed concern that widespread use of automated supervisory and control data acquisition SCADA systems for the critical infrastructure had allowed companies and agencies to systematically reduce the size of their work forces having the necessary technical knowledge needed to support manual operations of these infrastructure control systems, as might be needed during a prolonged emergency.

The Commission concluded, after reviewing national capabilities to manage the effects of nuclear weapons and EMP on modern systems, that "the Country is rapidly losing the technical competence in this area that it needs in the Government, National Laboratories, and Industrial Community. Experts on the Commission have asserted that little has been done by the private sector to protect against the threat from electromagnetic pulse, and that commercial electronic systems in the United States could be severely damaged by EMP attack.

In March , a survey of state Adjutants General who oversee National Guard units throughout the country found that most state-based emergency responders are not actively preparing against an attack on the United States by electromagnetic pulse.

Survey questions were sent to Adjutants General of all 50 states, with more than half responding. None of the Adjutants General surveyed indicated that they were actively involved in a formal planning process for response to an EMP attack. Some analysts discount the likelihood of a large-scale EMP attack against the United States in the near term, and the extent of possible damage, stating that the critical infrastructure reportedly would survive, and that military communications would continue to operate and a high percentage of civilian phone calls would continue to connect.

The argument is that limited testing has shown that modern commercial equipment may be surprisingly resistant to the effects of electromagnetic pulse, and that some military systems using commercial equipment are also retrofitted to be made more EMP resistant before they are fielded. However, other analysts maintain that some past testing done by the U.

These analysts also point out that EMP technology has been explored by several other nations, and as circuitry becomes more miniaturized, modern electronics become increasingly vulnerable to disruption. They argue that, depending on the targeted area and power of an EMP attack, it could possibly take years for the United States to recover fully from the resulting widespread damage to electronics and the power grid. Commission members have stated at hearings that, as time passes without a visible effort to show the world that we are protecting our computer systems and critical infrastructures, the perceived inaction may actually invite a possible EMP attack.

However, a single, low-yield nuclear explosion high above the United States, or over a battlefield, can produce a large-scale, high-altitude EMP effect resulting in widespread loss of electronics, but possibly without direct fatalities. Therefore, an EMP attack directed against the United States involving no violent destruction, nor instant death for large numbers of U.

Such a perceived lower risk of assured destruction by the United States, and widespread knowledge about the vulnerability of U. Electromagnetic energy, characterized as weapon potentially threatening to national security, can be created as a pulse traditionally by two methods: overhead nuclear burst and microwave emission.

High-Altitude Electromagnetic Pulse HEMP is a near-instantaneous electromagnetic energy field that is produced in the atmosphere by the power and radiation of a nuclear explosion, and that is damaging to electronic equipment over a very wide area, depending on power of the nuclear device and altitude of the burst. High-Power Microwave HPM electromagnetic energy can be produced as a near-instantaneous pulse created through special electrical equipment that transforms battery power, or powerful chemical reaction or explosion, into intense microwaves that are also very damaging to electronics, but within a much smaller area.

In addition, while HEMP weapons are large in scale and require a nuclear capability along with technology to launch high altitude missiles, HPM weapons are smaller in scale, and can involve a much lower level of technology that may be more easily within the capability of some extremist groups. HEMP is produced when a nuclear weapon is detonated high above the Earth's surface, creating gamma-radiation that interacts with the atmosphere to create an instantaneous intense electromagnetic energy field that is harmless to people as it radiates outward, but which can overload computer circuitry with effects similar to, but causing damage much more swiftly than, a lightning strike.

The HEMP effect can span thousands of miles, depending on the altitude and the design and power of the nuclear burst a single device detonated at an appropriate altitude over Kansas reportedly could affect all of the continental United States 17 , and can be picked up by metallic conductors such as wires, or overhead power lines, acting as antennas that conduct the energy shockwave into the electronic systems of cars, airplanes, or communications equipment.

A high altitude nuclear explosion that creates HEMP produces three major energy components that arrive in sequence, and which have measurably different effects that can be cumulatively damaging to electronic equipment.

The first energy component is the initial energy shockwave, which lasts up to 1 microsecond, and is similar to extremely intense static electricity that can overload circuitry for every electronic device that is within line of sight of the burst.

A secondary energy component then arrives, which has characteristics that are similar to a lightning strike. By itself, this second energy component might not be an issue for some critical infrastructure equipment, if anti-lightning protective measures are already in place. However, the rise time of the first component is so rapid and intense that it can destroy many protective measures, allowing the second component to further disrupt the electronic equipment. The third energy component is a longer-lasting magnetohydrodynamic MHD signal, about 1 microsecond up to many seconds in duration.

This late time pulse, or geomagnetic signal, causes an effect that is damaging primarily to long-lines electronic equipment. There are two components to this third late time energy pulse, which experts call "blast" and "heave. The "heave" comes from the heating and ionization of a patch of atmosphere directly below the bomb that rises and, being conductive, also distorts the earth's magnetic field. Both of these are considered MHD signals and are termed "slow" because they depend on the dynamics of cloud or fireball expansion.

As the fireball expands, a localized magnetic effect builds up on the ground throughout the length of long transmission lines and then quickly collapses, producing the MHD "late-time" power surge, which can overload equipment connected to the power grid and telecommunications infrastructure. This late-time effect can add to the initial HEMP effect, and systems connected to long-lines power and communications systems may be further disrupted by the combined effects. Smaller isolated systems do not collect so much of this third energy component, and are usually disrupted only by the first energy component of HEMP.

It is also important to note that this third, late-time pulse depends on the total energy of the nuclear detonation and therefore is usually associated only with larger yield nuclear weapons. However, the first energy pulse is a saturation-limited effect and is produced by all nuclear weapons, both small and large yield.

Microwaves are characterized by electromagnetic energy with wavelengths as small as centimeters or millimeters, and can be used at moderate power levels for radio frequency communications or for radar. HPM energy can be focused using a specially-shaped antenna, or emitter, to produce effects similar to HEMP within a confined area, or over a limited distance.

Unlike HEMP, however, HPM radiation uses shorter wave forms at higher-frequencies which make it highly effective against electronic equipment and more difficult to harden against.

A mechanically simple, suitcase-sized device, using a chemical explosive and special focusing antenna, might theoretically produce a one-time, instantaneous HPM shockwave that could disrupt many computers within a 1-mile range. Studies related to the effects of electromagnetic energy used as weapons have been published infrequently, or remain classified. Effectiveness is increased if the electronic devices are connected to any other metal that could also act as an antenna.

Because infrastructure computer systems are interconnected, a widespread HEMP effect could lead to possible long-term disruption of the power grid, fuel distribution, transportation systems, food and water supplies, and communications and equipment for hospitals and first responders, as well as military communications systems which utilize the civilian infrastructure.

An HPM weapon has a shorter possible range than HEMP, but it can induce currents large enough to melt circuitry, or it can cause equipment to gradually fail over a period of minutes, days, or even weeks. In , a U. Comanche helicopter, flying in New York while performing a radar test involving HPM weapons, generated a low-level energy pulse that reportedly disrupted for two weeks the global positioning systems GPS being used to land commercial aircraft at a nearby airport in Albany, New York.

A HEMP attack directed against the Unites States continent might involve a one-megaton nuclear warhead, or a smaller one, using a burst several hundred miles above the mid-western states to affect computers on both coasts. If a medium or higher range missile with a nuclear payload were launched from the deck of a freighter at sea, the resulting HEMP could reportedly disable computers over a wide area of the coastal United States.

The disruptive effects of both HEMP and HPM reportedly diminish with distance, and electronic equipment that is turned off is only less likely to be damaged. Also, HEMP produced by the nuclear explosion is instantaneous—too brief to start current flowing within a human body—so there is no effect on people. However, microwave energy weapons HPM are smaller-scale, are delivered at a closer range to the intended target, and can sometimes be emitted for a long duration.

These characteristics of HPM can sometimes cause a painful burning sensation or other injury to a person directly in the path of the focused power beam, or can even be fatal if a person is too close to the microwave emitter.

However, older electrical components, such as vacuum tubes and induction coils for spark ignition, are generally built more massively, and are more tolerant of EMP. As modern electronics shrink in size, circuitry is becoming increasingly tiny and more vulnerable to electromagnetic interference. Therefore, countries with infrastructure that relies on older technology may be less vulnerable to the disabling effects of HEMP or HPM than countries that rely on a higher level of technology.

The simultaneous loss of communications and power that would likely result from an EMP attack would also complicate the restoration of systems. Without communications, it would be difficult to ascertain the nature and location of damage, or to order personnel out to make repairs.

The estimated recovery times for various elements of the electrical system are provided in a list that appears on pages of the Commission report. The report states that the continuing business need to improve and expand the electric power system provides an opportunity to improve both the security and reliability of the entire system in an economically acceptable manner.

The Commission recommended that the federal government, according to standards it determines, should validate proposed enhancements to protect systems against damage from EMP attack, and fund those security related elements.

The study focuses on the economic effects of EMP experienced by a region after a high-altitude EMP pulse generated by a nuclear device detonated between miles above ground impacting an area at least miles in radius. In these instances of high-altitude EMP, no one would feel the heat or blast but merely experience the effects of the disruption or damage to the electronic and power infrastructure. The Baltimore-Washington-Richmond area likely comprises only one-tenth of the economic loss that would occur for the total geographic area affected by a regional EMP event.

The report was presents a range of low, medium, and high estimates of economic damage, all within bounds accepted by a broad range of EMP experts. The methodology relied on assumptions about disruption and damage to the regional electrical power system, communications systems, system control and data acquisition SCADA devices, and other critical infrastructure that might occur as a result of an EMP, and on the time required to repair that damage and fully restore economic activity.

Mobile Newsletter banner close. Mobile Newsletter chat close. Mobile Newsletter chat dots. Mobile Newsletter chat avatar. Mobile Newsletter chat subscribe. Prev NEXT. A switch connects the capacitors to the stator, sending an electrical current through the wires. This generates an intense magnetic field. A fuze mechanism ignites the explosive material.

The explosion travels as a wave through the middle of the armature cylinder. As the explosion makes its way through the cylinder, the cylinder comes in contact with the stator winding. This creates a short circuit, cutting the stator off from its power supply.

The survey will identify any equipment that could be vulnerable to an EMP ahead of more detailed vulnerability testing, according to the request. After that, officials would figure out ways to keep that equipment safe in the event of an EMP attack.

Related: The 22 weirdest military weapons. An EMP is a massive burst of electromagnetic energy that can occur naturally or be generated deliberately using nuclear weapons. While many experts don't think EMPs pose a big threat, some people argue that these types of weapons could be used to cause widespread disruption to electricity-dependent societies. According to the request, the testing at Lackland comes in response to a executive order issued by then-President Donald Trump for the federal government to strengthen its infrastructure against EMPs.

Pry, who has consulted on the project, said the survey and resulting upgrades are part of a broader initiative by the U. Air Force to beef up its defenses against this type of threat. An EMP releases huge waves of electromagnetic energy, which can act like a giant moving magnet. Such a changing magnetic field can cause electrons in a nearby wire to move, thereby inducing a current.

With such a huge burst of energy, an EMP can cause damaging power surges in any electronics within range. Related: Doomsdays: Top 9 real ways the world could end.