Directed-Energy
Weapons
see
also
Active
Denial System
(Video
see also
Secret Weapons in
Iraq
A directed-energy weapon is a type of weapon that emits
energy in a particular direction by a means other than a
projectile. It transfers energy to a target for a desired
effect. Some of these weapons are real or practicable; some
are science fiction. The energy is in various forms:
• Electromagnetic radiation (typically lasers or masers).
• Particles with mass (particle beam weapons).
• Fictional weapons often use some sort of radiation or
energetic particle that does not exist in the real world; or
where the physical nature of the energy and its means of
transmission is not detailed and the visible effects would be
impossible in the real world.
Some of these weapons are known as death rays or rayguns and
are usually portrayed as projecting energy at a person or
object to kill or destroy.
Some lethal directed-energy weapons are under active research
and development, but most examples appear in science fiction
(or non-functional toys and film props).
Types
Broadly defined, directed-energy weapons can be categorised
according to the type of energy used (sound, radio, light,
particles, plasma, etc) and the intended effects on the
target (physical damage, interference with senses and
guidance, disorientation, disabling machinery, incapacitating
people, etc).
This article restricts itself to weapons designed to cause
physical damage with electromagnetic or particle beams.
• For weapons to interfere with communications, i.e. jamming,
see Electronic countermeasures, Electronic warfare, Radio
jamming, and Radar jamming.
• For weapons to blind or disorient or interfere with the
human eye or electronic sensors see Dazzler (weapon). This is
the first verifiable use of directed-energy as a weapon (as
opposed to jamming) and dates from World War II.
• For particle beams see also Particle beam weapon.
• For laser weapons see this article and Laser applications.
• For sonic and ultrasonic beam weapons see Sonic
weaponry.
For some devices which may be confused with directed-energy
weapons see:
• Laser designators are usually infrared lasers used for
selective illumination of a target for navigating a
laser-guided bomb. They are relatively high-power, often
using a solid-state laser, eg Nd:YAG or Eu:YAG.
• The term electroshock gun includes two sorts of weapons,
but neither of these is a directed-energy weapon, despite its
name.
• The electric shock prod administers an electric shock on
contact. It is not strictly a gun, as it does not cause any
effect at a distance.
• Guns which fire an electrified projectile.
• Occasionally science fiction authors misuse the name
"thermic lance" to mean a raygun, but the real thermal lance
is not a gun.
Lasers
Lasers are very well known in science fiction as a type of
raygun. In the real world, lasers are often used for
sighting, ranging and targeting for guns; but the laser beam
is not the source of the weapon's firepower.
Laser weapons usually generate brief high-energy pulses. A
million joules delivered as a laser pulse is roughly the same
energy as 200g of high explosive, and has the same basic
effect on a target. The primary damage mechanism is
mechanical shear, caused by reaction (like a rocket) when the
surface of the target is explosively evaporated.
Most existing weaponized lasers are gas dynamic lasers. Fuel,
or a powerful turbine, pushes the lasing media through a
circuit or series of orifices. The high-pressures and heating
cause the medium to form a plasma and lase. A major
difficulty with these systems is preserving the
high-precision mirrors and windows of the laser resonating
cavity. Most systems use a low-powered "oscillator" laser to
generate a coherent wave, and then amplify it. Some
experimental laser amplifiers do not use windows or mirrors,
but have open orifices, which cannot be destroyed by high
energies.
There is research on real lasers as non-lethal weapons. See
Dazzler.
Tactical considerations
Lasers
have four main advantages over conventional weaponry:
• Laser beams travel at the speed of light, unlike projectile
weapons, so there is no need in terrestrial applications to
aim ahead to allow for the target moving while the shot
travels as the transit time over such distances is virtually
zero.
• Light's short transit time also nearly eliminates the
influence of gravity, so long range projection does not
require compensation for such.
• Some lasers run on electricity which can be cheaply
generated, reducing the need for expensive and finite
ammunition. However, getting portable electric power sources
of sufficient energy capacity is a problem.
• Because light has a practically nil ratio (exactly 1 / c)
of momentum to energy, lasers produce negligible recoil.
Since lasers can theoretically defeat artillery and missile
attacks, any group fielding an effective laser system will
gain decisive advantages in ground, air and space combat.
Under radar control, lasers have shot artillery shells in
flight, including mortar rounds. This suggests that a primary
application of lasers might be as part of a defensive system.
The main difficulty with currently practical lasers is the
high expense and fragility of their mirrors and
mirror-pointing systems.
Some believe that mirrors or other countermeasures can reduce
the effectiveness of high energy lasers. This has not been
demonstrated. Small defects in mirrors absorb energy, and the
defects rapidly expand across the surface. Protective
mirroring on the outside of a target could easily be made
less effective by incidental damage and by dust and dirt on
its surface.
Problems with lasers
Blooming
Laser beams begin to cause plasma breakdown in the air at
energy densities of around a megajoule per square centimeter.
This effect, called "blooming", causes the laser to defocus
and to lose energy to the atmosphere. It can be more severe
if there is fog, smoke, or dust in the air.
There are several ways to stop or reduce blooming:
• The beam can be distributed over a large mirror that
focuses the power on the target, to keep energy density in
the air 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.
• A phased array. For the usual laser wavelengths this method
would need billions of micrometre-size antennas, and no way
to make these is known. Phased arrays could theoretically
also perform phase-conjugate amplification (see below).
• A phase-conjugate laser system. Here, a "finder" or "guide"
laser illuminates the target. Any mirror-like ("specular")
points on the target reflect light that is sensed by the
weapon's primary amplifier. The weapon-power amplifier then
amplifies inverted waves in a positive feedback loop,
destroying the target with shockwaves as the specular regions
evaporate. This avoids the blooming problem because the waves
from the target passed 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, the mirror
overheats dramatically at weaponized power levels.
• A very short pulse that finishes before blooming
interferes.
• Tailoring the pulse timing, power, and/or wavelength of the
laser to induce a shockwave that evacuates the path between
the target and the weapon. Without air in the laser's path,
blooming will not occur. However, it is difficult to achieve
the amount of power needed to blast the air out of the way.
• Limiting these weapons to use in vacuum, for example space.
Evaporated
target material shading the target
Another
problem with weaponized lasers is that the evaporated
material from the surface of the target begins to shade the
surface. There are several approaches to this problem:
• One is to induce a standing shockwave in the ablation
cloud. The shockwave then continues to perform damage.
• Another scheme is to scan the target faster than the
shockwave.
• Another theoretical possibility is to induce plasmic
optical mixing at the target. In this scheme, the
transparency of the target's ablation cloud to one laser is
modulated by another laser, perhaps by tuning the laser to
the absorption spectra of the ablation cloud, and inducing
population inversion in the cloud. The other laser then
induces local lasing in the ablation cloud. The beat
frequency that results can induce frequencies that penetrate
the ablation cloud.
High power consumption
One
major problem with laser weapons (and directed-energy weapons
in general) is their high energy requirements. Existing
methods of storing, conducting, transforming, and directing
energy are inadequate to produce a convenient hand-held
weapon. Existing lasers are inefficient and waste much energy
as heat, and thus need much power and bulky cooling equipment
to avoid damage by overheating. Simple air cooling could
leave an impractical amount of time between when the device
can be safely activated again. These problems, which severely
limit laser weapon practicality at present, might be offset
by:
1. Cheap high-temperature superconductors to make the weapon
more efficient.
2. A new method of conveniently storing and/or generating
large amounts of electricity needed to power the weapon.
If
only #2 is available, part of the energy could be used to
cool the device.
This problem of storing and/or supplying electrical energy is
offset in chemical lasers by using energy released in a
suitable chemical reaction instead. Chemical oxygen iodine
laser (hydrogen peroxide with iodine) and deuterium fluoride
laser (atomic fluorine reacting with deuterium) are two
examples of laser types capable of megawatt-range output of a
continuous beam. Storing and transporting the chemical fuel
presents its own problems with these lasers, and the problems
of cooling and overall inefficiency remain.
Beam absorbed by obscuration in the air
A
laser beam or particle beam passing through air can be
absorbed or scattered by rain, snow, dust, fog, smoke, or
similar visual obstructions that a bullet would easily brush
aside. This effect adds to blooming and worsens the
efficiency of the weapon, by wasting more energy to an
atmosphere.
Lack of indirect fire capabilities
Because
light is only marginally affected by gravity, and indirect
fire requires the use of gravity to strike an enemy from
behind cover or not in line-of-sight, lasers cannot be used
for indirect fire. However, mounting lasers on airborne or
space-based platforms may circumvent this limitation simply
by getting around or above an obstruction that provides cover
or blocks line-of-sight.
Electrolaser
An electrolaser lets blooming occur, and then sends a
powerful electric current down the conducting ionized track
of plasma so formed, somewhat like lightning. It functions as
a giant high energy long-distance version of the Taser or
stun gun.
Microwaves
Microwave
guns powerful enough to injure humans are possible.
•
Active Denial
System
is a microwave source, to heat the water in the target's skin
and thus cause incapacitating pain. It is being developed by
the Air Force Research Laboratory in New Mexico by
researchers working with Raytheon for riot-control duty in
Iraq. Though intended to cause severe pain while leaving no
lasting damage, some concern has been voiced as to if the
system could cause irreversible damage to the eyes. However,
such damage, being non-lethal, would still be preferable to
the damage caused by conventional munitions. There has yet to
be testing for long-term side effects of exposure to the
microwave beam. It can destroy unshielded electronics.
• See VMADS (Vehicle-Mounted Active Denial System)
Microwave weapons also have considerable anti-material
applications, as they are capable of disabling or destroying
unhardened electronics. The components of a microwave weapon
- a power source, microwave generator and an antenna - are
all readily available, and civilians have successfully built
and tested simple devices in this category.
• The United States, in cooperation with the Canadian
Government, built and successfully tested a microwave gun. It
was shown working on a willing soldier (a Canadian) on
American and Canadian television.
Pulsed Energy Projectile
Pulsed
Energy Projectile or PEP systems emit an infrared laser pulse
which creates rapidly expanding plasma when meeting 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 to be used as a
non-lethal weapon in crowd control.
MIRACL
The Mid-Infrared Advanced Chemical Laser is an experimental
U.S. Navy deuterium fluoride laser which was tested against
an Air Force satellite in 1997.
THEL
THEL (Tactical High Energy Laser) is a weaponized deuterium
fluoride laser developed in a joint research project of
Israel and the U.S. It is designed to shoot down aircraft and
missiles. See also National Missile Defense.
Airborne Laser
The U.S. Air Force's Airborne Laser, or Advanced tactical
laser, is a plan to mount a CO2 gas laser or COIL chemical
laser on a modified Boeing 747 and use it to shoot down
missiles. [1]
Ultraviolet laser
HSV
Technologies of San Diego is developing a laser weapon to
paralyze animals (testing for later use on humans) by an
electric charge generated by the laser beam. It is described
as an ultraviolet laser and not an electrolaser. [1]
Boeing YAL-1
The
U.S. military has recently developed the Boeing YAL-1, which
is an airplane-based laser weapon supposedly capable of
shooting down ICBMs. [2]
Radio frequency
HERF
cannons (high-energy radio-frequency weapons), which work on
the same principles as microwave ovens, have also shown
potential.
On January 25, 2007 the US Military unveiled a device
mountable on a small armored vehicle (hummer). It resembles a
satellite dish. It can make people feel around 130 degrees
from around 500 yards away, hotter if closer. It is not clear
yet if the weapon has the capability to burn or kill. Full
scale production of such a weapon is not expected until at
least 2010. It is probably the Active Denial System.
Electric beam in a vacuum
In
a vacuum (e.g. in space), an electric discharge can travel a
potentially unlimited distance at a velocity slightly slower
than the speed of light. This is because there is no
significant electric resistance to the flow of electric
current in a vacuum. This would make such devices useful to
destroy the electrical and electronic parts of satellites and
spacecraft. However, in a vacuum the electric current cannot
ride a laser beam, and some other means must be used to keep
the electron beam on track and to prevent it from dispersing:
see particle beam.
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. Certain types of particle
beams have the advantage of being self-focusing in the
atmosphere.
Blooming is not limited to lasers, but is also a problem in
particle beam weapons. Energy that would otherwise be focused
on the target spreads out; 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 or bolt of plasma, which is excited
matter consisting of electrons and also protons or nuclei.
Examples are:
• The MARAUDER (Magnetically Accelerated Ring to Achieve
Ultra-high Directed Energy and Radiation). See this link for
more details; the antiaircraft potential of such a system is
mentioned.
• This explains theories about ball lightning, which may be a
type of plasma, which if weaponized could produce beam
weapons guided in the same sense as an Anti-tank guided
missile
• The plasma rifle is a staple of science fiction. There may
have been influence from the real plasma torch used to cut
metal.
• The discontinued Shiva Star project was to be a system for
shooting down incoming missiles with projectiles of plasma
traveling at speeds from 3,000 kilometers per second to
10,000 kilometers per second.
• MEDUSA (Mobile Energy Device USA). Normally, the electrons
are collected or recaptured at the end of the klystron, a
specialized vacuum tube. But by allowing them to stream
freely to the high power microwave and high energy laser
assembly, they’re turned into potentially lethal projectiles
able to instantly destroy inorganic and organic material.See
[3] for more details; the many lethal and peaceful uses of
the device is discussed.
Urban legends
Engine-stopping rays
Engine-stopping
rays are a variant that occurs in fiction and myth. Such
stories were circulating in Britain around 1938. The tales
varied but in general terms told of tourists whose car engine
suddenly died and were then 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. A possible origin of some of these
stories arises 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. A distorted retelling
of the events might give rise to the idea that a transmission
killed the engine (Jones 1978).
A shoulder-mounted engine-stopping weapon was a central plot
element in episode 303 of BBC espionage drama serial Bugs, in
which it was referred to as an "engine killer".
Also see electromagnetic pulse.
Low-powered lasers
This
is not a weapon, but is included here for completeness. There
is an imitation shotgun which fires a low-powered laser beam
at a target which is covered with reflective 90° corners
designed to send the beam back where it came from to be
detected by a detector on the gun. This is only for target
practice without using up ammunition; it has the disadvantage
(for a shotgun user) that the beam travels at the speed of
light and in a straight line, without teaching the shooter to
allow for the effects of wind deflecting the fired shot and
the target moving while the shot travels.
History
Mythology
Before
modern technology developed, many mythologies described gods
or demons using weapons that make lightning, such as
Zeus's/Jupiter's thunderbolts, Thor's hammer Mjolnir, and the
Hindu god Indra's spear (the vajrā).
Ancient inventors
According
to mythology, the concept of the "burning mirror" or death
ray began with Archimedes who 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. A Byzantine writer hundreds of years
later is suggested to have imagined this 2200-year-old death
ray, which is attributed to Archimedes. Some attempts to
replicate this feat have had some success (though not the
attempt by the MythBusters television program). In
particular, an experiment by students at MIT showed that a
mirror-based weapon was at least possible, if not necessarily
practical.[2]
Grindell-Matthews
After
the astonishing technological advancement during World War I,
many such schemes began to appear credible. Harry
Grindell-Matthews tried to sell such a ray to the British Air
Ministry after that war. He failed to appear to demonstrate
his apparatus, however. It was apparently taken to France but
has not resurfaced, leading to various conspiracy theory
ideas about what might have happened to it, or who might have
developed it later.
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. See: History of radar#Robert Watson-Watt.
Tesla
Nikola
Tesla (1856 - 1943) was a noted inventor, scientist and
electrical engineer. He invented Tesla coils, transformers,
alternating current electrical generators and was a major
early pioneer of radio technology.
He was also noted for making some outlandish claims, among
them that he had developed what he called a "teleforce"
weapon, or death ray. This death ray would "send concentrated
beams of particles through the free air, of such tremendous
energy that they will bring down a fleet of 10,000 enemy
airplanes at a distance of 250 miles from a defending
nation's border and will cause armies of millions to drop
dead in their tracks", as said in an article at the time. He
offered this invention to the U.S. War Department and to
several European countries without success. Various
conspiracy theories persist regarding the nature of this
device and the whereabouts of Tesla's model or schematics for
it.
H.G. Wells
H.
G. Wells, in his book The War of the Worlds, for the first
time used a "death ray" like laser in science fiction, in the
form of the Martians "Heat-Ray", which used a heat beam with
many properties of the modern laser as a weapon. The weapon
used a parabolic mirror to focus and direct a beam of pure
heat that had many of the properties of light. This
ultimately made 'death ray' like weapons popular in science
fiction, which may have stimulated interest in developing
real-life directed-energy weapons.
Nazis
In
the later phases of WWII, Nazi Germany increasingly put its
hopes on research into technologically revolutionary secret
weapons, the Wunderwaffe.
Among the directed-energy weapons the Nazis investigated were
sonic weaponry, using parabolic reflectors to project sound
waves of destructive force.
This Nazi research included searching in India in the hope
that some of the powerful weapons and flying craft described
in the Mahabharata and other old Indian books were the real
products of supposed ancient technology, rather than
mythology based on lightning and other destructive natural
forces.
FAIR USE
NOTICE: This site may contain copyrighted material, the use
of which has not been specifically authorized by the
copyright owner. This website distributes this material
without profit to those who have expressed a prior interest
in receiving the included information for research and
educational purposes. We believe this constitutes a fair use
of any such copyrighted material as provided for in 17 U.S.C
§ 107.
NOTE TO AUTHORS: If you are the author or owner of an article
or video that I have made available through THEINFOVAULT.NET
and you do not wish to have your article or video posted on
theinfovault, please contact me and I
will remove the item.