Electromagnetic pulse

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Electromagnetic_pulse

An electromagnetic pulse (EMP), also sometimes called a transient electromagnetic disturbance, is a short burst of electromagnetic energy. Such a pulse's origin may be a natural occurrence or human-made and can occur as a radiated, electric, or magnetic field or a conducted electric current, depending on the source.

EMP interference is generally disruptive or damaging to electronic equipment, and at higher energy levels a powerful EMP event such as a lightning strike can damage physical objects such as buildings and aircraft structures. The management of EMP effects is an important branch of electromagnetic compatibility (EMC) engineering.

Weapons have been developed to deliver the damaging effects of high-energy EMP.

According to research from Homeland security, EMP weapons have the potential to disrupt unprotected critical infrastructure within the US and could impact millions over large parts of the country.  There's concern about the EMP threat but there's no accurate prediction on how many people will face massive damages from this attack.

According to research from Martin and Mathew Weiss, of the scenarios that might lead to electrical network collapse, EMP has received the widest public attention. The threat possiblity of an EMP attack has grown more as a possiblity than it did in the past when it wasn't seen as an incoming threat to the United States.

General characteristics

An electromagnetic pulse is a short surge of electromagnetic energy. Its short duration means that it will be spread over a range of frequencies. Pulses are typically characterized by:

• The type of energy (radiated, electric, magnetic or conducted).
• The range or spectrum of frequencies present.
• Pulse waveform: shape, duration and amplitude.

The last two of these, the frequency spectrum and the pulse waveform, are interrelated via the Fourier transform and may be seen as two ways of describing the same pulse.

Types of energy

EMP energy may be transferred in any of four forms:

• Electric field
• Magnetic field
• Electromagnetic radiation
• Electrical conduction

According to Maxwell's equations, a pulse of electric energy will always be accompanied by a pulse of magnetic energy. In a typical pulse, either the electric or the magnetic form will dominate.

In general, radiation only acts over long distances, with the magnetic and electric fields acting over short distances. There are a few exceptions, such as a solar magnetic flare.

Frequency ranges

A pulse of electromagnetic energy typically comprises many frequencies from very low to some upper limit depending on the source. The range defined as EMP, sometimes referred to as "DC to daylight", excludes the highest frequencies comprising the optical (infrared, visible, ultraviolet) and ionizing (X and gamma rays) ranges.

Some types of EMP events can leave an optical trail, such as lightning and sparks, but these are side effects of the current flow through the air and are not part of the EMP itself.

Pulse waveforms

The waveform of a pulse describes how its instantaneous amplitude (field strength or current) changes over time. Real pulses tend to be quite complicated, so simplified models are often used. Such a model is typically described either in a diagram or as a mathematical equation.

Rectangular pulse

Double exponential pulse

Damped sinewave pulse

Most electromagnetic pulses have a very sharp leading edge, building up quickly to their maximum level. The classic model is a double-exponential curve which climbs steeply, quickly reaches a peak and then decays more slowly. However, pulses from a controlled switching circuit often approximate the form of a rectangular or "square" pulse.

EMP events usually induce a corresponding signal in the surrounding environment or material. Coupling usually occurs most strongly over a relatively narrow frequency band, leading to a characteristic damped sine wave. Visually it is shown as a high frequency sine wave growing and decaying within the longer-lived envelope of the double-exponential curve. A damped sinewave typically has much lower energy and a narrower frequency spread than the original pulse, due to the transfer characteristic of the coupling mode. In practice, EMP test equipment often injects these damped sinewaves directly rather than attempting to recreate the high-energy threat pulses.

In a pulse train, such as from a digital clock circuit, the waveform is repeated at regular intervals. A single complete pulse cycle is sufficient to characterise such a regular, repetitive train.

Types

An EMP arises where the source emits a short-duration pulse of energy. The energy is usually broadband by nature, although it often excites a relatively narrow-band damped sine wave response in the surrounding environment. Some types are generated as repetitive and regular pulse trains.

Different types of EMP arise from natural, man-made, and weapons effects.

Types of natural EMP event includes:

• Lightning electromagnetic pulse (LEMP). The discharge is typically an initial huge current flow, at least mega-amps, followed by a train of pulses of decreasing energy.
• Electrostatic discharge (ESD), as a result of two charged objects coming into close proximity or even contact.
• Meteoric EMP. The discharge of electromagnetic energy resulting from either the impact of a meteoroid with a spacecraft or the explosive breakup of a meteoroid passing through the Earth's atmosphere.
• Coronal mass ejection (CME), sometimes referred to as a solar EMP. A burst of plasma and accompanying magnetic field, ejected from the solar corona and released into the solar wind.

Types of (civil) man-made EMP event include:

• Switching action of electrical circuitry, whether isolated or repetitive (as a pulse train).
• Electric motors can create a train of pulses as the internal electrical contacts make and break connections as the armature rotates.
• Gasoline engine ignition systems can create a train of pulses as the spark plugs are energized or fired.
• Continual switching actions of digital electronic circuitry.
• Power line surges. These can be up to several kilovolts, enough to damage electronic equipment that is insufficiently protected.

Types of military EMP include:

• Nuclear electromagnetic pulse (NEMP), as a result of a nuclear explosion. A variant of this is the high altitude nuclear EMP (HEMP), which produces a secondary pulse due to particle interactions with the Earth's atmosphere and magnetic field.
• Non-nuclear electromagnetic pulse (NNEMP) weapons.

Lightning

Lightning is unusual in that it typically has a preliminary "leader" discharge of low energy building up to the main pulse, which in turn may be followed at intervals by several smaller bursts.

Electrostatic discharge (ESD)

ESD events are characterised by high voltages of many kV but small currents and sometimes cause visible sparks. ESD is treated as a small, localised phenomenon, although technically a lightning flash is a very large ESD event. ESD can also be man-made, as in the shock received from a Van de Graaff generator.

An ESD event can damage electronic circuitry by injecting a high-voltage pulse, besides giving people an unpleasant shock. Such an ESD event can also create sparks, which may in turn ignite fires or fuel-vapour explosions. For this reason, before refuelling an aircraft or exposing any fuel vapour to the air, the fuel nozzle is first connected to the aircraft to safely discharge any static.

Switching pulses

The switching action of an electrical circuit creates a sharp change in the flow of electricity. This sharp change is a form of EMP.

Simple electrical sources include inductive loads such as relays, solenoids, and the brush contacts in electric motors. These typically send a pulse down any electrical connections present, as well as radiating a pulse of energy. The amplitude is usually small and the signal may be treated as "noise" or "interference". The switching off or "opening" of a circuit causes an abrupt change in the current flowing. This can in turn cause a large pulse in the electric field across the open contacts, causing arcing and damage. It is often necessary to incorporate design features to limit such effects.

Electronic devices such as vacuum tubes or valves, transistors and diodes can also switch on and off very quickly, causing similar issues. One-off pulses may be caused by solid-state switches and other devices used only occasionally. However, the many millions of transistors in a modern computer may switch repeatedly at frequencies above 1 GHz, causing interference which appears to be continuous.

Nuclear electromagnetic pulse (NEMP)

A nuclear electromagnetic pulse is the abrupt pulse of electromagnetic radiation resulting from a nuclear explosion. The resulting rapidly changing electric fields and magnetic fields may couple with electrical/electronic systems to produce damaging current and voltage surges.

The intense gamma radiation emitted can also ionize the surrounding air, creating a secondary EMP as the atoms of air first lose their electrons and then regain them.

NEMP weapons are designed to maximize such EMP effects as the primary damage mechanism, and some are capable of destroying susceptible electronic equipment over a wide area.

A high-altitude electromagnetic pulse (HEMP) weapon is a NEMP warhead designed to be detonated far above the Earth's surface. The explosion releases a blast of gamma rays into the mid-stratosphere, which ionizes as a secondary effect and the resultant energetic free electrons interact with the Earth's magnetic field to produce a much stronger EMP than is normally produced in the denser air at lower altitudes.

Non-nuclear electromagnetic pulse (NNEMP)

Non-nuclear electromagnetic pulse (NNEMP) is a weapon-generated electromagnetic pulse without use of nuclear technology. Devices that can achieve this objective include a large low-inductance capacitor bank discharged into a single-loop antenna, a microwave generator, and an explosively pumped flux compression generator. To achieve the frequency characteristics of the pulse needed for optimal coupling into the target, wave-shaping circuits or microwave generators are added between the pulse source and the antenna. Vircators are vacuum tubes that are particularly suitable for microwave conversion of high-energy pulses.

NNEMP generators can be carried as a payload of bombs, cruise missiles (such as the CHAMP missile) and drones, with diminished mechanical, thermal and ionizing radiation effects, but without the consequences of deploying nuclear weapons.

The range of NNEMP weapons is much less than nuclear EMP. Nearly all NNEMP devices used as weapons require chemical explosives as their initial energy source, producing only 10⁻⁶ (one millionth) the energy of nuclear explosives of similar weight. The electromagnetic pulse from NNEMP weapons must come from within the weapon, while nuclear weapons generate EMP as a secondary effect. These facts limit the range of NNEMP weapons, but allow finer target discrimination. The effect of small e-bombs has proven to be sufficient for certain terrorist or military operations. Examples of such operations include the destruction of electronic control systems critical to the operation of many ground vehicles and aircraft.

The concept of the explosively pumped flux compression generator for generating a non-nuclear electromagnetic pulse was conceived as early as 1951 by Andrei Sakharov in the Soviet Union, but nations kept work on non-nuclear EMP classified until similar ideas emerged in other nations.

Electromagnetic forming

The large forces generated by electromagnetic pulses can be used to shape or form objects as part of their manufacturing process.

Effects

Minor EMP events, and especially pulse trains, cause low levels of electrical noise or interference which can affect the operation of susceptible devices. For example, a common problem in the mid-twentieth century was interference emitted by the ignition systems of gasoline engines, which caused radio sets to crackle and TV sets to show stripes on the screen. Laws were introduced to make vehicle manufacturers fit interference suppressors.

At a high voltage level an EMP can induce a spark, for example from an electrostatic discharge when fuelling a gasoline-engined vehicle. Such sparks have been known to cause fuel-air explosions and precautions must be taken to prevent them.

A large and energetic EMP can induce high currents and voltages in the victim unit, temporarily disrupting its function or even permanently damaging it.

A powerful EMP can also directly affect magnetic materials and corrupt the data stored on media such as magnetic tape and computer hard drives. Hard drives are usually shielded by heavy metal casings. Some IT asset disposition service providers and computer recyclers use a controlled EMP to wipe such magnetic media.

A very large EMP event such as a lightning strike is also capable of damaging objects such as trees, buildings and aircraft directly, either through heating effects or the disruptive effects of the very large magnetic field generated by the current. An indirect effect can be electrical fires caused by heating. Most engineered structures and systems require some form of protection against lightning to be designed in.

The damaging effects of high-energy EMP have led to the introduction of EMP weapons, from tactical missiles with a small radius of effect to nuclear bombs designed for maximum EMP effect over a wide area.

Control

EMP simulator HAGII-C testing a Boeing E-4 aircraft.

 

EMPRESS I (antennas along shoreline) with USS Estocin (FFG-15) moored in the foreground for testing.

Like any electromagnetic interference, the threat from EMP is subject to control measures. This is true whether the threat is natural or man-made.

Therefore, most control measures focus on the susceptibility of equipment to EMP effects, and hardening or protecting it from harm. Man-made sources, other than weapons, are also subject to control measures in order to limit the amount of pulse energy emitted.

The discipline of ensuring correct equipment operation in the presence of EMP and other RF threats is known as electromagnetic compatibility (EMC).

Test simulation

To test the effects of EMP on engineered systems and equipment, an EMP simulator may be used.

Induced pulse simulation

Induced pulses are of much lower energy than threat pulses and so are more practicable to create, but they are less predictable. A common test technique is to use a current clamp in reverse, to inject a range of damped sine wave signals into a cable connected to the equipment under test. The damped sine wave generator is able to reproduce the range of induced signals likely to occur.

Threat pulse simulation

Sometimes the threat pulse itself is simulated in a repeatable way. The pulse may be reproduced at low energy in order to characterise the victim's response prior to damped sinewave injection, or at high energy to recreate the actual threat conditions.

A small-scale ESD simulator may be hand-held.

Bench- or room-sized simulators come in a range of designs, depending on the type and level of threat to be generated.

At the top end of the scale, large outdoor test facilities incorporating high-energy EMP simulators have been built by several countries. The largest facilities are able to test whole vehicles including ships and aircraft for their susceptibility to EMP. Nearly all of these large EMP simulators used a specialized version of a Marx generator.

Examples include the huge wooden-structured ATLAS-I simulator (also known as TRESTLE) at Sandia National Labs, New Mexico, which was at one time the world's largest EMP simulator. Papers on this and other large EMP simulators used by the United States during the latter part of the Cold War, along with more general information about electromagnetic pulses, are now in the care of the SUMMA Foundation, which is hosted at the University of New Mexico. The US Navy also has a large facility called the Electro Magnetic Pulse Radiation Environmental Simulator for Ships I (EMPRESS I).

Safety

High-level EMP signals can pose a threat to human safety. In such circumstances, direct contact with a live electrical conductor should be avoided. Where this occurs, such as when touching a Van de Graaf generator or other highly-charged object, care must be taken to release the object and then discharge the body through a high resistance, in order to avoid the risk of a harmful shock pulse when stepping away.

Very high electric field strengths can cause breakdown of the air and a potentially lethal arc current similar to lightning to flow, but electric field strengths of up to 200 kV/m are regarded as safe.

According to research from Edd Gent, a 2019 report by the Electric Power Research Institute, which is funded by utility companies, found that such an attack would probably cause regional blackouts but not a nationwide grid failure and that recovery times would be similar to those of other large-scale outages.

It is not known how long these electrical blackouts causes by an EMP attack will last and the extent of damage across the country.

According to research from Lindsay Marchello, The detonation would generate an EMP field covering the entire country, Canada, and much of Mexico and cause the destruction of our electronic civilization.

It is possible that neighboring countries of the U.S. could also be affected by the attack, depending on the targeted area and people.

According to research from Naureen Malik, Nevertheless, with North Korea's increasingly successful missile and warhead tests in mind, Congress moved to renew funding for the Commission to Assess the Threat to the U.S. from Electromagnetic Pulse Attack as part of the National Defense Authorization Act. At the moment, the United States lacks preparation against a EMP attack.

According to research from Yoshida Reiji, in a 2016 article for the Tokyo-based nonprofit organization Center for Information and Security Trade Control, Onizuka warned that a high-altitude EMP attack would damage or destroy Japan's power, communications and transport systems as well as disable banks, hospitals and nuclear power plants.

According to research from Martin and Mathew Weiss, in testimony before a Congressional Committee, it has been asserted that a prolonged collapse of this nation's electrical grid—through starvation, disease, and societal collapse—could result in the death of up to 90% of the American population.

In popular culture

The popular media often depict EMP effects incorrectly, causing misunderstandings among the public and even professionals. Official efforts have been made in the U.S. to disprove these misconceptions.

Directed-energy weapon

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Directed-energy_weapon 

A directed-energy weapon (DEW) is a ranged weapon that damages its target with highly focused energy, including laser, microwaves, and particle beams. Potential applications of this technology include weapons that target personnel, missiles, vehicles, and optical devices.

In the United States, the Pentagon, DARPA, the Air Force Research Laboratory, United States Army Armament Research Development and Engineering Center, and the Naval Research Laboratory are researching directed-energy weapons and railguns to counter ballistic missiles, hypersonic cruise missiles, and hypersonic glide vehicles. These systems of missile defense are expected to come online no sooner than the mid to late-2020s.

Russia, China, India and the United Kingdom are also developing directed-energy weapons while Iran and Turkey claim to have directed-energy weapons in active service. The first usage of directed-energy weapons in a combat was claimed to have occurred in Libya in August 2019 by Turkey, which claimed to use the ALKA Directed-energy weapon.

After decades of research and development, directed-energy weapons are still at the experimental stage and it remains to be seen if or when they will be deployed as practical, high-performance military weapons.

Operational advantages

Directed energy weapons could have several main advantages over conventional weaponry:

• Directed-energy weapons can be used discreetly; radiation above and below the visible spectrum is invisible and does not generate sound.
• Light is, for all practical purposes, essentially unaffected by gravity, windage and Coriolis force, giving it an almost perfectly flat trajectory. This makes aim much more precise and extends the range to line-of-sight, limited only by beam diffraction and spread (which dilute the power and weaken the effect), and absorption or scattering by intervening atmospheric contents.
• Lasers travel at light-speed and have near infinite range and are therefore suitable for use in space warfare.
• Laser weapons potentially eliminate many logistical problems in terms of ammunition supply, as long as there is enough energy to power them.
• Depending on several operational factors, directed-energy weapons may be cheaper to operate than conventional weapons in certain contexts.

Microwave weapons

Although some devices are labeled as microwave weapons, the microwave range is commonly defined as being between 300 MHz and 300 GHz, which is within the RF range—these frequencies having wavelengths of 1 millimeter to 1 meter. Some examples of weapons which have been publicized by the military are as follows:

• Active Denial System is a millimeter wave source that heats the water in a human target's skin and thus causes incapacitating pain. It was developed by the U.S. Air Force Research Laboratory and Raytheon for riot-control duty. Though intended to cause severe pain while leaving no lasting damage, concern has been voiced as to whether the system could cause irreversible damage to the eyes. There has yet to be testing for long-term side effects of exposure to the microwave beam. It can also destroy unshielded electronics. The device comes in various sizes, including attached to a Humvee.
• Vigilant Eagle is a proposed airport defense system that directs high-frequency microwaves towards any projectile that is fired at an aircraft. The system consists of a missile-detecting and tracking subsystem (MDT), a command and control system, and a scanning array. The MDT is a fixed grid of passive infrared (IR) cameras. The command and control system determines the missile launch point. The scanning array projects microwaves that disrupt the surface-to-air missile's guidance system, deflecting it from the aircraft.
• Bofors HPM Blackout is a high-powered microwave weapon that is said to be able to destroy at short distance a wide variety of commercial off-the-shelf (COTS) electronic equipment and is purportedly non-lethal.
• The effective radiated power (ERP) of the EL/M-2080 Green Pine radar makes it a hypothetical candidate for conversion into a directed-energy weapon, by focusing pulses of radar energy on target missiles. The energy spikes are tailored to enter missiles through antennas or sensor apertures where they can fool guidance systems, scramble computer memories or even burn out sensitive electronic components.
• AESA radars mounted on fighter aircraft have been slated as directed energy weapons against missiles, however, a senior US Air Force officer noted: "they aren't particularly suited to create weapons effects on missiles because of limited antenna size, power and field of view". Potentially lethal effects are produced only inside 100 meters range, and disruptive effects at distances on the order of one kilometer. Moreover, cheap countermeasures can be applied to existing missiles.
• Counter-electronics High Power Microwave Advanced Missile Project

Laser weapons

A laser weapon is a directed-energy weapon based on lasers.

Particle-beam weapons

Particle-beam weapons can use charged or neutral particles, and can be either endoatmospheric or exoatmospheric. Particle beams as beam weapons are theoretically possible, but practical weapons have not been demonstrated yet. Certain types of particle beams have the advantage of being self-focusing in the atmosphere.

Blooming is also a problem in particle-beam weapons. Energy that would otherwise be focused on the target spreads out and the beam becomes less effective:

• Thermal blooming occurs in both charged and neutral particle beams, and occurs when particles bump into one another under the effects of thermal vibration, or bump into air molecules.
• Electrical blooming occurs only in charged particle beams, as ions of like charge repel one another.

Plasma weapons

Plasma weapons fire a beam, bolt, or stream of plasma, which is an excited state of matter consisting of atomic electrons & nuclei and free electrons if ionized, or other particles if pinched.

The MARAUDER (Magnetically Accelerated Ring to Achieve Ultra-high Directed-Energy and Radiation) used the Shiva Star project (a high energy capacitor bank which provided the means to test weapons and other devices requiring brief and extremely large amounts of energy) to accelerate a toroid of plasma at a significant percentage of the speed of light.

The Russian Federation is developing plasma weapons.

Sonic weapons

Tests performed on mice show the threshold for both lung and liver damage occurs at about 184 dB. Damage increases rapidly as intensity is increased. Noise-induced neurological disturbances in humans exposed to continuous low frequency tones for durations longer than 15 minutes involved development of immediate and long-term problems affecting brain tissue. The symptoms resembled those of individuals who had suffered minor head injuries. One theory for a causal mechanism is that the prolonged sound exposure resulted in enough mechanical strain to brain tissue to induce an encephalopathy.

Long Range Acoustic Device (LRAD)

The LRAD is the round black device on top of the New York City police Hummer.

The Long Range Acoustic Device (LRAD) is an acoustic hailing device developed by LRAD Corporation to send messages and warning tones over longer distances or at higher volume than normal loudspeakers. LRAD systems are used for long-range communications in a variety of applications including as a means of non-lethal, non-kinetic crowd control.

According to the manufacturer's specifications, the systems weigh from 15 to 320 pounds (6.8 to 145.1 kg) and can emit sound in a 30°- 60° beam at 2.5 kHz.

History

Mirrors of Archimedes

Archimedes may have used mirrors acting collectively as a parabolic reflector to burn ships attacking Syracuse.

According to a legend, Archimedes created a mirror with an adjustable focal length (or more likely, a series of mirrors focused on a common point) to focus sunlight on ships of the Roman fleet as they invaded Syracuse, setting them on fire. Historians point out that the earliest accounts of the battle did not mention a "burning mirror", but merely stated that Archimedes's ingenuity combined with a way to hurl fire were relevant to the victory. Some attempts to replicate this feat have had some success; in particular, an experiment by students at MIT showed that a mirror-based weapon was at least possible, if not necessarily practical. The hosts of MythBusters tackled the Mirrors of Archimedes three times (in episodes 19, 57 and 172) and were never able to make the target ship catch fire, declaring the myth busted three separate times.

Robert Watson-Watt

In 1935, the British Air Ministry asked Robert Watson-Watt of the Radio Research Station whether a "death ray" was possible. He and colleague Arnold Wilkins quickly concluded that it was not feasible, but as a consequence suggested using radio for the detection of aircraft and this started the development of radar in Britain.

The fictional "engine-stopping ray"

Stories in the 1930s and World War Two gave rise to the idea of an "engine-stopping ray". They seemed to have arisen from the testing of the television transmitter in Feldberg, Germany. Because electrical noise from car engines would interfere with field strength measurements, sentries would stop all traffic in the vicinity for the twenty minutes or so needed for a test. Reversing the order of events in retelling the story created a "tale" where tourists car engine stopped first and then were approached by a German soldier who told them that they had to wait. The soldier returned a short time later to say that the engine would now work and the tourists drove off. Such stories were circulating in Britain around 1938 and during the war British Intelligence relaunched the myth as a "British engine-stopping ray," trying to spoof the Germans into researching what the British had supposedly invented in an attempt to tie up German scientific resources.

German World War II experimental weapons

During the early 1940s Axis engineers developed a sonic cannon that could cause fatal vibrations in its target body. A methane gas combustion chamber leading to two parabolic dishes pulse-detonated at roughly 44 Hz. This sound, magnified by the dish reflectors, caused vertigo and nausea at 200–400 meters (220–440 yd) by vibrating the middle ear bones and shaking the cochlear fluid within the inner ear. At distances of 50–200 meters (160–660 ft), the sound waves could act on organ tissues and fluids by repeatedly compressing and releasing compressive resistant organs such as the kidneys, spleen, and liver. (It had little detectable effect on malleable organs such as the heart, stomach and intestines.) Lung tissue was affected at only the closest ranges as atmospheric air is highly compressible and only the blood rich alveoli resist compression. In practice, the weapon was highly vulnerable to enemy fire. Rifle, bazooka and mortar rounds easily deformed the parabolic reflectors, rendering the wave amplification ineffective.

In the later phases of World War II, Nazi Germany increasingly put its hopes on research into technologically revolutionary secret weapons, the Wunderwaffe.

Among the directed-energy weapons the Nazis investigated were X-ray beam weapons developed under Heinz Schmellenmeier, Richard Gans and Fritz Houtermans. They built an electron accelerator called Rheotron (invented by Max Steenbeck at Siemens-Schuckert in the 1930s, these were later called Betatrons by the Americans) to generate hard X-ray synchrotron beams for the Reichsluftfahrtministerium (RLM). The intent was to pre-ionize ignition in aircraft engines and hence serve as anti-aircraft DEW and bring planes down into the reach of the flak. The Rheotron was captured by the Americans in Burggrub on April 14, 1945.

Another approach was Ernst Schiebolds 'Röntgenkanone' developed from 1943 in Großostheim near Aschaffenburg. Richert Seifert & Co from Hamburg delivered parts.

Reported use in Sino-Soviet conflicts

The Central Intelligence Agency informed Secretary Henry Kissinger that it had twelve reports of Soviet forces using laser-based weapons against Chinese forces during the 1969 Sino-Soviet border clashes, though William Colby doubted that they had actually been employed.

Strategic Defense Initiative

In the 1980s, U.S. President Ronald Reagan proposed the Strategic Defense Initiative (SDI) program, which was nicknamed Star Wars. It suggested that lasers, perhaps space-based X-ray lasers, could destroy ICBMs in flight. Panel discussions on the role of high-power lasers in SDI took place at various laser conferences, during the 1980s, with the participation of noted physicists including Edward Teller.

Though the strategic missile defense concept has continued to the present under the Missile Defense Agency, most of the directed-energy weapon concepts were shelved. However, Boeing has been somewhat successful with the Boeing YAL-1 and Boeing NC-135, the first of which destroyed two missiles in February 2010. Funding has been cut to both of the programs.

Iraq War

During the Iraq War, electromagnetic weapons, including high power microwaves, were used by the U.S. military to disrupt and destroy Iraqi electronic systems and may have been used for crowd control. Types and magnitudes of exposure to electromagnetic fields are unknown.

Alleged tracking of Space Shuttle Challenger

The Soviet Union invested some effort in the development of ruby and carbon dioxide lasers as anti-ballistic missile systems, and later as a tracking and anti-satellite system. There are reports that the Terra-3 complex at Sary Shagan was used on several occasions to temporarily "blind" US spy satellites in the IR range.

It has been claimed (and proven false) that the USSR made use of the lasers at the Terra-3 site to target the Space Shuttle Challenger in 1984. At the time, the Soviet Union were concerned that the shuttle was being used as a reconnaissance platform. On 10 October 1984 (STS-41-G), the Terra-3 tracking laser was allegedly aimed at Challenger as it passed over the facility. Early reports claimed that this was responsible for causing "malfunctions on the space shuttle and distress to the crew", and that the United States filed a diplomatic protest about the incident. However, this story is comprehensively denied by the crew members of STS-41-G and knowledgeable members of the US intelligence community. After the end of the Cold War, the Terra-3 facility was found to be a low-power laser testing site with limited satellite tracking capabilities, which is now abandoned and partially disassembled.

Planetary defense

In the United States, the Directed Energy Solar Targeting of Asteroids and exploRation (DE-STAR) Project was considered for non-military use to protect Earth from asteroids.

Non-lethal weapons

The TECOM Technology Symposium in 1997 concluded on non-lethal weapons, "determining the target effects on personnel is the greatest challenge to the testing community", primarily because "the potential of injury and death severely limits human tests".

Also, "directed-energy weapons that target the central nervous system and cause neurophysiological disorders may violate the Certain Conventional Weapons Convention of 1980. Weapons that go beyond non-lethal intentions and cause 'superfluous injury or unnecessary suffering' may also violate the Protocol I to the Geneva Conventions of 1977."

Some common bio-effects of non-lethal electromagnetic weapons include:

• Difficulty breathing
• Disorientation
• Nausea
• Pain
• Vertigo
• Other systemic discomfort

Interference with breathing poses the most significant, potentially lethal results.

Light and repetitive visual signals can induce epileptic seizures. Vection and motion sickness can also occur.

Cruise ships are known to use sonic weapons (such as LRAD) to drive off pirates.

Russia has been reportedly using blinding laser weapons during its military intervention in Donbass.

Laser weapon

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Laser_weapon 

 

The US-Israeli Tactical High Energy Laser (THEL) was used to shoot down rockets and artillery shells before being canceled in 2005 as a result of "its bulkiness, high costs and poor anticipated results on the battlefield.".

A laser weapon is a directed-energy weapon based on lasers. After decades of R&D, as of January 2020 directed-energy weapons including lasers are still at the experimental stage and it remains to be seen if or when they will be deployed as practical, high-performance military weapons. Atmospheric thermal blooming has been a major problem, still mostly unsolved and worsened if there is fog, smoke, dust, rain, snow, smog, foam, or purposely dispersed obscurant chemicals in the air. Essentially, a laser generates a beam of light which needs clear air, or a vacuum to work without thermal blooming. Laser and other directed-energy weapons have been a staple in science fiction since their inception however.

Many types of laser can potentially be used as incapacitating weapons, through their ability to produce temporary or permanent vision loss when aimed at the eyes. The degree, character, and duration of vision impairment caused by eye exposure to laser light varies with the power of the laser, the wavelength(s), the collimation of the beam, the exact orientation of the beam, and the duration of exposure. Lasers of even a fraction of a watt in power can produce immediate, permanent vision loss under certain conditions, making such lasers potential non-lethal but incapacitating weapons. The extreme handicap that laser-induced blindness represents makes the use of lasers even as non-lethal weapons morally controversial, and weapons designed to cause permanent blindness have been banned by the Protocol on Blinding Laser Weapons.

Weapons designed to cause temporary blindness, known as dazzlers, are used by military and sometimes law enforcement organizations. Incidents of pilots being exposed to lasers while flying have prompted aviation authorities to implement special procedures to deal with such hazards.

Laser weapons capable of directly damaging or destroying a target in combat are still in the experimental stage. The general idea of laser-beam weaponry is to hit a target with a train of brief pulses of light. The rapid evaporation and expansion of the surface causes shockwaves that damage the target. The power needed to project a high-powered laser beam of this kind is beyond the limit of current mobile power technology, thus favoring chemically powered gas dynamic lasers. Example experimental systems included MIRACL and the Tactical High Energy Laser, which are now discontinued.

The United States Navy has tested the very short range (1 mile), 30-kW Laser Weapon System or LaWS to be used against targets like small UAVs, rocket-propelled grenades, and visible motorboat or helicopter engines. It has been defined as "six welding lasers strapped together." A 60 kW system, HELIOS, is being developed for destroyer class ships as of 2020.

Overview

Laser-based directed-energy weapons are being developed, such as Boeing's Airborne Laser which was constructed inside a Boeing 747. Designated the YAL-1, it was intended to kill short- and intermediate-range ballistic missiles in their boost phase.

Another example of direct use of a laser as a defensive weapon was researched for the Strategic Defense Initiative (SDI, nicknamed "Star Wars"), and its successor programs. This project would use ground-based or space-based laser systems to destroy incoming intercontinental ballistic missiles (ICBMs). The practical problems of using and aiming these systems were many; particularly the problem of destroying ICBMs at the most opportune moment, the boost phase just after launch. This would involve directing a laser through a large distance in the atmosphere, which, due to optical scattering and refraction, would bend and distort the laser beam, complicating the aiming of the laser and reducing its efficiency.

Another idea from the SDI project was the nuclear-pumped X-ray laser. This was essentially an orbiting atomic bomb, surrounded by laser media in the form of glass rods; when the bomb exploded, the rods would be bombarded with highly-energetic gamma-ray photons, causing spontaneous and stimulated emission of X-ray photons in the atoms making up the rods. This would lead to optical amplification of the X-ray photons, producing an X-ray laser beam that would be minimally affected by atmospheric distortion and capable of destroying ICBMs in flight. The X-ray laser would be a strictly one-shot device, destroying itself on activation. Some initial tests of this concept were performed with underground nuclear testing; however, the results were not encouraging. Research into this approach to missile defense was discontinued after the SDI program was canceled.

Electrolaser

An electrolaser first ionizes its target path, and then sends an electric current down the conducting track of ionized plasma, somewhat like lightning. It functions as a giant, high-energy, long-distance version of the Taser or stun gun.

Pulsed energy projectile

Pulsed Energy Projectile or PEP systems emit an infrared laser pulse which creates rapidly expanding plasma at the target. The resulting sound, shock and electromagnetic waves stun the target and cause pain and temporary paralysis. The weapon is under development and is intended as a non-lethal weapon in crowd control though it can also be used as a lethal weapon.

Dazzler

A dazzler is a directed-energy weapon intended to temporarily blind or disorient its target with intense directed radiation. Targets can include sensors or human vision. Dazzlers emit infrared or invisible light against various electronic sensors, and visible light against humans, when they are intended to cause no long-term damage to eyes. The emitters are usually lasers, making what is termed a laser dazzler. Most of the contemporary systems are man-portable, and operate in either the red (a laser diode) or green (a diode-pumped solid-state laser, DPSS) areas of the electromagnetic spectrum.

Initially developed for military use, non-military products are becoming available for use in law enforcement and security.

PHASR Rifle

The personnel halting and stimulation response rifle (PHASR) is a prototype non-lethal laser dazzler developed by the Air Force Research Laboratory's Directed Energy Directorate, U.S. Department of Defense. Its purpose is to temporarily disorient and blind a target. Blinding laser weapons have been tested in the past, but were banned under the 1995 United Nations Protocol on Blinding Laser Weapons, which the United States acceded to on 21 January 2009. The PHASR rifle, a low-intensity laser, is not prohibited under this regulation, as the blinding effect is intended to be temporary. It also uses a two-wavelength laser. The PHASR was tested at Kirtland Air Force Base, part of the Air Force Research Laboratory Directed Energy Directorate in New Mexico.

• ZM-87
• PY132A is a Chinese anti-drone dazzler.
• Soviet laser pistol was a prototype weapon designed for cosmonauts.
• Optical Dazzling Interdictor, Navy (ODIN) is a U.S. laser to be field tested in 2019 on an Arleigh Burke-class destroyer.

Examples

Leading Western companies in the development of laser weapons have been Boeing, Northrop Grumman, Lockheed Martin, Netherlands Organisation for Applied Scientific Research, Rheinmetall and MBDA.

List:

• Project Excalibur was a United States government nuclear weapons research program to develop a nuclear pumped x-ray laser as a directed energy weapon for ballistic missile defense. Canceled.
• In 1984, the Soviet Strategic Missile Troops military academy developed the first handheld laser weapon, intended for use by cosmonauts in outer space. No longer used.
• 1K17 Szhatie: An experimental Soviet self-propelled laser weapon. Never went beyond the experimental stage.
• In 1987, a Soviet laser-armed orbital weapon, the 17F19DM Polyus/Skif-DM, failed during deployment.
• The Soviet Terra-3 laser facility was widely thought to be a powerful anti-satellite weapon prototype, but after the Cold War ended it was found to be a testing site with limited satellite tracking capabilities. The site was abandoned and is now partially disassembled.
• In 1991, scientists at the US Army Missile Command developed and field tested a ruggedized tunable laser emitting narrow-linewidth in the yellow-orange-red part of the spectrum. Never went beyond the experimental stage.

Boeing YAL-1. The laser system was mounted in a turret attached to the aircraft nose

• Throughout the 2000s, the United States Air Force worked on the Boeing YAL-1, or ATL, an airborne CO2 gas laser or COIL chemical laser mounted in a modified Boeing 747. It was intended to be used to shoot down incoming ballistic missiles over enemy territory. In March 2009, Northrop Grumman claimed that its engineers in Redondo Beach had successfully built and tested an electrically powered solid state laser capable of producing a 100-kilowatt beam, powerful enough to destroy an airplane. According to Brian Strickland, manager for the United States Army's Joint High Power Solid State Laser program, an electrically powered laser is capable of being mounted in an aircraft, ship, or other vehicle because it requires much less space for its supporting equipment than a chemical laser. However, the source of such a large electrical power in a mobile application remained unclear. Ultimately, the project was deemed to be infeasible, and was canceled in December 2011, with the Boeing YAL-1 prototype being stored and eventually dismantled.
• Precision Airborne Standoff Directed Energy Weapon (2008). Canceled.
• On 19 July 2010, an anti-aircraft laser described as the Laser Close-In Weapon System was unveiled at the Farnborough Airshow. Experimental.
• The ZEUS-HLONS (HMMWV Laser Ordnance Neutralization System) is the first laser and the first energy weapon of any type to be used on a battlefield. It is used for neutralizing mines and unexploded ordnance. Niche application.
• High Energy Liquid Laser Area Defense System (HELLADS). Status unknown.
• The Mid-Infrared Advanced Chemical Laser (MIRACL) was an experimental U.S. Navy deuterium fluoride laser and was tested against an Air Force satellite in 1997. Canceled.
• In 2011, the U.S. Navy began to test the Maritime Laser Demonstrator (MLD), a laser for use aboard its warships. Status unknown.
• Personnel Halting and Stimulation Response, or PHaSR, is a non-lethal hand-held weapon developed by the United States Air Force Its purpose is to "dazzle" or stun a target. It was developed by Air Force's Directed Energy Directorate. Status unknown.
• Tactical High Energy Laser (THEL) was a weaponized deuterium fluoride laser developed in a joint research project by Israel and the U.S. It was designed to shoot down aircraft and missiles. See also National missile defense. Discontinued in 2005 as a result of "its bulkiness, high costs and poor anticipated results on the battlefield", which are characteristic problems of all medium- and high-energy laser weapons.

The Beriev A-60 is still experimenting with the Sokol Eshelon laser as an intended anti-satellite weapon.

• Soviet/Russian Beriev A-60: a CO₂ gas laser mounted on an Ilyushin Il-76MD transport. Experimental.
• High Energy Laser-Mobile Demonstrator (HEL-MD) is a Boeing designed laser system mounted on a Heavy Expanded Mobility Tactical Truck (HEMTT). Its current power level is 10 kW, which will be boosted to 50 kW, and expected to eventually be upgraded to 100 kW. Targets that can be engaged are mortar rounds, artillery shells and rockets, unmanned aerial vehicles, and cruise missiles. Status unknown.
• Lockheed Martin is developing a 60 kW fiber laser to mount on the HEMTT that maintains beam quality at high power outputs while using less electricity than solid-state lasers. Status unknown.
• Free-electron laser (FEL) technology is being evaluated by the US Navy as a candidate for an antiaircraft and anti-missile directed-energy weapon. The Thomas Jefferson National Accelerator Facility's FEL has demonstrated over 14 kW power output. Compact multi-megawatt class FEL weapons are undergoing research. On June 9, 2009 the Office of Naval Research announced it had awarded Raytheon a contract to develop a 100 kW experimental FEL. On March 18, 2010 Boeing Directed Energy Systems announced the completion of an initial design for U.S. Naval use. A prototype FEL system was demonstrated, with a full-power prototype scheduled by 2018. Experimental.
• Portable Efficient Laser Testbed (PELT) Status unknown.
• Laser AirCraft CounterMeasures (ACCM) Status unknown.
• Mobile Expeditionary High-Energy Laser (MEHEL) 2.0 Experimental.
• Area Defense Anti-Munitions (ADAM) Experimental.
• Advanced Test High Energy Asset (ATHENA) Status unknown.
• Self-Protect High-Energy Laser Demonstrator (SHiELD). Pre-prototype stage.
• Silent Hunter (laser weapon) is a Chinese fiber-optic laser air-defense system. A 2017 article describes a Chinese directed-energy weapon called Silent Hunter that can burn through two 5-millimeter steel plates from a range of 1000 meters. Status unknown.
• Russian Sokol Eshelon. Experimental.
• Russian Peresvet. Mobile air-defense laser, undergoing service testing as close-range mobile ICBM escorts.
• Raytheon Company announced that it developed a high-energy laser that can be mounted on a MRZR and used to disable an unmanned aerial system from approximately 1 mile away. Status unknown.
• ZKZM-500. Short-range antipersonnel less-lethal weapon.
• Made by Northrop Grumman:
  • On 18 March 2009, Northrop Grumman announced that its engineers in Redondo Beach had successfully built and tested an electric laser capable of producing a 100-kilowatt ray of light, powerful enough to destroy cruise missiles, artillery, rockets and mortar rounds. An electric laser is theoretically capable, according to Brian Strickland, manager for the United States Army's Joint High Power Solid State Laser program, of being mounted in an aircraft, ship, or vehicle because it requires much less space for its supporting equipment than a chemical laser. Experimental.
  • On 6 April 2011, the U.S. Navy successfully tested a laser gun, manufactured by Northrop Grumman, that was mounted on the former USS Paul F. Foster, which is currently used as the navy's test ship. When engaged during the test that occurred off the coast of Central California in the Pacific Ocean test range, the laser gun was documented as having "a destructive effect on a high-speed cruising target", said Chief of Naval Research Admiral Nevin Carr. Experimental.
  • Skyguard (area defense system). Proposed.
• On 19 July 2010, an anti-aircraft laser described as the Laser Close-In Weapon System was unveiled at the Farnborough Airshow.
• Area Defense Anti-Munitions (ADAM) Lockheed Martin experimental fiber laser. 10 kilowatt tested against rockets.
• In 2011, the U.S. Navy began to test the Maritime Laser Demonstrator (MLD), a laser for use aboard its warships. By 2013, the Navy was announcing active deployment in 2014.
• Personnel halting and stimulation response rifle (PHaSR) A non-lethal hand-held weapon developed by the United States Air Force. Its purpose is to "dazzle" or stun a target. It was developed by U.S. Air Force's Directed Energy Directorate. Blinding weapon: banned.
• The Russian truck-mounted Almaz HEL
• Boeing Laser Avenger Mounted on an AN/TWQ-1 Avenger combat vehicle. Small anti-drone weapon. Experimental.
• Portable Efficient Laser Testbed (PELT) Anti-riot less-lethal weapon. Status unknown.
• Laser AirCraft CounterMeasures (ACCM)
• High Energy Liquid Laser Area Defense System (HELLADS) A counter-RAM aircraft or truck-mounted laser under development by General Atomics under a DARPA contract. 150 kilowatt goal. Uses a lasing medium immersed in an index matched coolant.
• Turkey's laser weapon ARMOL passed acceptance tests in 2019. Experimental.
• In 2014, the U.S. began field testing a 30 kW directed-energy weapon it calls the AN/SEQ-3 Laser Weapon System (LaWS) onboard USS Ponce while deployed in the Persian Gulf. The tests went well and the system was declared operational. It was moved to USS Portland (LPD-27) after Ponce was decommissioned. A second unit was ordered to be installed on USS Arleigh Burke (DDG-51). It has been proved to be effective against small, unprotected targets at very short distance.
• In August 2017, India's Defence Research and Development Organisation was reportedly able to create a hole in a metal sheet kept at a distance of 250 meters in 36 seconds using a 1-kilowatt laser weapon.
• The 60 kW High Energy Laser and Integrated Optical-dazzler and Surveillance (HELIOS) will be tested on an Arleigh Burke–class destroyer in 2021. Prototype.
• The Pulsed energy projectile (PAP) is a controversial, truck-mounted riot control laser-based less-lethal weapon to be used against civilians. A laser pulse ablates material causing a shockwave which stuns the targeted individual.
• In May 2020, the Technology Maturation Laser Weapon System Demonstrator (LWSD) installed on the USS Portland (LPD-27) successfully managed to destroy an unprotected, small, non-maneouvering unmanned aerial vehicle (UAV) at very short distance. Experimental.

Most of these projects have been canceled, discontinued, never went beyond the prototype or experimental stage, or are only used in niche applications like dazzling, blinding, mine clearance or close defense against small, unprotected targets. Effective, high performance laser weapons seem to be difficult to achieve using current or near-future technology.

Problems

Laser beams begin to cause plasma breakdown in the atmosphere at energy densities of around one megajoule per cubic centimeter. This effect, called "blooming," causes the laser to defocus and disperse energy into the surrounding air. Blooming can be more severe if there is fog, smoke, dust, rain, snow, smog, or foam in the air.

Techniques that may reduce these effects include:

• Spreading the beam across a large, curved mirror that focuses the power on the target, to keep energy density en route too low for blooming to happen. This requires a large, very precise, fragile mirror, mounted somewhat like a searchlight, requiring bulky machinery to slew the mirror to aim the laser.
• Using a phased array. For typical laser wavelengths, this method would require billions of micrometer-size antennae. There is currently no known way to implement these, though carbon nanotubes have been proposed. Phased arrays could theoretically also perform phase-conjugate amplification (see below). Phased arrays do not require mirrors or lenses, and can be made flat and thus do not require a turret-like system (as in "spread beam") to be aimed, though range will suffer if the target is at extreme angles to the surface of the phased array.
• Using a phase-conjugate laser system. This method employs a "finder" or "guide" laser illuminating the target. Any mirror-like ("specular") points on the target reflect light that is sensed by the weapon's primary amplifier. The weapon then amplifies inverted waves, in a positive feedback loop, destroying the target, with shockwaves as the specular regions evaporate. This avoids blooming because the waves from the target pass through the blooming, and therefore show the most conductive optical path; this automatically corrects for the distortions caused by blooming. Experimental systems using this method usually use special chemicals to form a "phase-conjugate mirror". In most systems, however, the mirror overheats dramatically at weapon-useful power levels.
• Using a very short pulse that finishes before blooming interferes, but this requires a very high power laser to concentrate large amounts of energy in that pulse which doesn't exist in a weaponized or easily weaponizable form.
• Focusing multiple lasers of relatively low power on a single target. This is increasingly bulky as the total power of the system increases.

Countermeasures

Essentially, laser generates a beam of light which will be delayed or stopped by any opaque medium and perturbed by any translucent or less than perfectly transparent medium just like any other type of light. A simple, dense smoke screen can and will often block a laser beam. Infrared or multi-spectrum smoke grenades or generators will also disturb or block infrared laser beams. Any opaque case, cowling, bodywork, fuselage, hull, wall, shield or armor will absorb at least the "first impact" of a laser weapon, so the beam must be sustained to achieve penetration.

The Chinese People's Liberation Army has invested in the development of specialized coatings that can deflect beams fired by U.S. military lasers. Laser light can be deflected, reflected, or absorbed by manipulating physical and chemical properties of materials. Artificial coatings can counter certain specific types of lasers, but a different type of laser may match the coating's absorption spectrum enough to transfer damaging amounts of energy. The coatings are made of several different substances, including low-cost metals, rare earths, carbon fiber, silver, and diamonds that have been processed to fine sheens and tailored against specific laser weapons. China is developing anti-laser defenses because protection against them is considered far cheaper than creating competing laser weapons.

Dielectric mirrors, inexpensive ablative coatings, thermal transport delay, and obscurants are also being studied as countermeasures. In not a few operational situations, even simple, passive countermeasures like rapid rotation (which spreads the heat and does not allow a fixed targeting point except in strictly frontal engagements), higher acceleration (which increases the distance and changes the angle quickly), or agile maneuvering during the terminal attack phase (which hampers the ability to target a vulnerable point, forces a constant re-aiming or tracking with close to zero lag, and allows for some cooling) can defeat or help to defeat non-highly pulsed, high-energy laser weapons.

In popular culture

Arthur C. Clarke envisaged particle beam weapons in his 1955 novel Earthlight, in which energy would be delivered by high-velocity beams of matter. After the invention of the laser in 1960, it briefly became the death ray of choice for science fiction writers. By the late 1960s and 1970s, as the laser's limits as a weapon became evident, the ray gun began to be replaced by similar weapons with names that better reflected the destructive capabilities of the device (like the blasters in Star Wars or the phasers in Star Trek, which were originally lasers: according to The Making of Star Trek, Gene Roddenberry claimed that production staff realized that using laser technology would cause problems in the future as people came to understand what lasers could and could not do; this resulted in the move to phasers on-screen, while letting lasers be known as a more primitive weapon style.)

In the Warhammer 40,000 franchise, a faction known as the Astra Militarum, formerly called the Imperial Guard, uses a wide variety of laser weapons. The "lasgun" or "lasrifle" is their main infantry weapon and is used in the same manner as a modern-day assault rifle. Lasguns are presented as cheap, easy to mass-produce and reliable, albeit not very effective against heavily armoured targets unless fielded in large numbers. The Astra Militarum also make extensive use of laser technology in the forms of sidearms (laspistols, hellpistols/hot-shot laspistols), special weapons used primarily by special forces or elite units (Hellgun/Hot-shot Lasgun, Hotshot Volley Gun), sniper weapons (Long-Las), heavy weapons (lascannon, multi-laser, laser destroyer, magma cannon, volcano cannon) or weapons used in planetary defense systems for planetary defense such as anti-voidship defence lasers. The Aeldari, formerly the Eldar, have a special unit called the Swooping Hawks equipped with "lasblasters" and their laser weapons are typically more refined, accurate, and energy-efficient. Orks also make use of laser weapons, usually scavenged or looted laser weapons from other races that have been "orkified" for more power, but at the cost of reliability.

In the Command & Conquer video game series, various factions make extensive use of laser and particle beam technology.