Plasma weapon

For plasma weaponry in fiction, see plasma weapon (fiction).

A plasma weapon is any theoretical firearm designed to use plasma (high-energy ionized gas) as a weapon. The plasma is typically intended to be created by superheating lasers or superfrequency devices.

Such weapons can be intended to be lethal, causing death by serious burns or the melting of targets, or non-lethal and intended to disrupt electronics using an electromagnetic pulse.

While no practical example of such weaponry has been produced, corporations such as Boeing have funded research and development into the technology.

Current research

Boeing has considered furthering the research of plasma weapons and directed energy weapons, or DEW. Boeing Phantom Works has several ideas, one of which is that a plasma weapon aboard a hypersonic aircraft could possibly skim off the plasma that naturally forms around the airframe of a vehicle traveling at Mach eight. They hypothesize that this captured plasma could then be redirected by a focusing system and used as a weapon. There is an apparent interest in plasma for aerospace technologies in the U.S.

A nonlethal weapon designed to use a laser to induce a high energy state in gases is currently being funded by the United States military. The leading tip of the incoming beam ionized the target material, while the remainder is absorbed by this newly created plasma causing it to expand rapidly. This rapid expansion not only has an effect similar to a flash-bang grenade, but also creates an extremely strong EM field which is tunable through the output of the laser itself. This EM field stimulates nerves throughout the body triggering muscle paralysis and/or intense sensations of pain. There have been concerns that the technology may be unethically used, as it is possible to stimulate pain nerves throughout a person's body creating unimaginable levels of agony.

Date: 5.07.07

When the two patents below are carefully read, a conclusion can be reached that a plasma column can be created in the atmosphere and used as an antenna to transmit to a target on the ground. That target might be a person.

"Columnar focal lens" 5,900,986 Air Force patent

short excerpt:

The concept of utilizing a plasma generated by laser guided electric discharges in the atmosphere as the conducting element of an antenna . . . . The principal objective was the development of an antenna with no physical structure, but with large effective area.

The present invention is a lens that produces a columnar focus with the axis of the focal column perpendicular to the principal plane of the lens. The lens refracts an incident wave front with a focal length that is dependent upon the radial distance from the axis of the lens. These foci produce a focal column. The radii of curvature of the primary surface of the lens are dependent upon the desired length of the focal column. The thus focused radiation can be used to generate free electron surfaces in the atmosphere for use as an antenna, to act as an electromagnetic transmission line, to induce lightning strikes, or for electronic counter measure purposes. The invention can also be used for end cavity pumping of a laser medium.

"Horizontal plasma antenna using plasma drift currents" 6,118,407 Navy patent

short excerpt:

A horizontal plasma antenna is provided. An ionizer generates an ionizing am through a horizontal tube to form a bounded plasma column extending along a horizontal axis in a gravity field. An amplitude or frequency modulating signal is applied to Helmholtz coils to control a horizontal magnetic field that is perpendicular to the horizontal axis. The resulting changes in the magnetic field produce a drift current in the plasma that, in turn, radiates an amplitude or phase modulated electromagnetic field from the plasma column.

One can ionize the atmosphere by just heating it up with electromagnetics (laser, microwaves, etc.), but it is much easier to generate plasma if one dumps barium, carbon, and aluminum into the atmosphere first.

With the assistance of a $2.7 Million U.S. contract, Stellar Photonics is developing a Plasma Acoustic Shield System, or PASS. The PASS uses a high-energy laser to create an airborne ball of plasma, then uses another laser to create a shock wave inside the plasma ball, creating a flash of light and explosion.

This link leads to a "heavily censored document" which is a twelve page Navy contract with the Univ. of Florida to "study the consequences of using an electromagnetic pulse emitted by laser induced plasma channels" on humans. The contract states that several directed energy weapons can be used alone or with each other to induce non-lethal to lethal attacks. From researching the various direct energy weapons included in the contract, it has been revealed that the weapons cramp muscles, pound on bones, stab joints, attack tissue and various organs of the body.

Practicality of plasma weapons

At present, plasma weapons are merely theoretical, as currently they need more power than any handheld device could supply. If small portable fusion reactors are made, one potential source of weapons-grade plasma sources might be a direct tap on a fusion reactor, especially a dense plasma focus, since the natural yield of such a reactor is a hot high-speed plasma beam. Making real plasma weapons will need a major scientific breakthrough, as the concept of plasma-firing weapons is scientifically difficult, for various reasons:

• The technology to create plasma compact toroids and particle beams is presently far too bulky for anything man-portable. In such a high-performance design, the plasma would have to be stored and created in highly focused magnetic bottles, such as those used in NASA's VASIMR rocket: this design has been suggested as a potential weapon design for future real human-engineered plasma weapons. For simpler designs based on plasma cutting torches, a designer might be able to heat the plasma with an arcjet, if his power source is strong enough.
• Using current technology, if a plasma beam was fired in a planetary atmosphere, it would quickly be stopped by atmospheric resistance and would make a short hot flame like a blow torch.
• The plasma shot out of a plasma weapon would tend to dissipate in the surrounding environment within about 50 centimeters from the gun, from thermal and/or electric pressure expansion, called blooming, unless:
  • The magnetic confinement bottle is extended all the way to the target. Modifications to this bottle could make the plasma home in on its target.
  • The plasma is somehow made self-sustaining over a much longer time period (as with ball lightning).
  • The particles are fired fast enough to reach a target before blooming occurs. This is then a particle beam more than a plasma shot (at least as much as any technical definition for such weapons exists). This would work for use outside atmosphere (i.e. in a space vacuum), but within an atmosphere would merely cause a hotter short flame from more violent collision between the flying particles and the atmosphere.
  • It might also be possible to generate a laser beam "tunnel". High-energy lasers ionize the air around the beam, heating the atmosphere and providing the plasma bolt with an easy passage to the target (see electrolaser).
  • Another laser-assisted plasma weapon approach for use in atmosphere is possible if the laser is powerful enough to blast the air out of the way, but having the plasma particles reach the target before the newly-created vacuum channel collapses in on itself is a problem unless the weapon possesses sufficient power to either sustain the channel or the aforementioned "plasma particle beam" approach is used.
  • It may also be possible to encase a bolt of plasma in a capsule of some material, possibly a polymer. This would allow the plasma to reach a medium distance before the capsule wears out. For an example see the Plasma Pistol from UFO: Alien Invasion.
• One common characteristic of plasma weaponry is its tendency to overheat, thus being sometimes impractical even within the context of science fiction. Two of the more well-known examples include the vulnerable cooling times for the plasma weapons in the Halo series, or the venting of built-up heat from powerful but unstable plasma weapons (capable of seriously injuring or killing its user) designed by the Imperium of Man in the Warhammer 40,000 universe.
• Another weakness present in some works of fiction is the tendency of the plasma blast to 'explode' the first time it touches anything, like a leaf, twig, or raindrop. This is used to explain how a war in a forest environment with such powerful weapons could not last more than a few seconds.
• A plasma round would glow very brightly due to blackbody radiation, leading to quick substantial energy loss. This might also represent a blinding hazard for the operator and bystanders. From basic physics, a 1 cm ball of plasma at 10,000 Kelvin (K) would be equal to a 700 kilowatt (kw) bulb. 1000 K would equate to a 70 W bulb.
• Many materials already exist that are highly resistant to plasma, reinforced carbon-carbon used on the Space Shuttle's nose cone for example; or the ceramic inserts used in bulletproof vests.

With a railgun a 'plasma/particle thrower' similar to a long range natural gas flamethrower could possibly be made. Most railguns throw a trail of plasma (of the rail material and projectile material) out after or with the projectile: this is very short lived but extends over 3 to 30 feet. This is because of arcing of the rails and projectile. The plasma conducts and so is subject to the working force of all railguns (Lorentz force). The plasma thrower would use a rapid-fire small projectile and very thick rails spring/actuator mounted that move inwards with wear. A tungsten-aluminium-chromium alloy for both the rails and projectile would yield good results but the projectiles would have to be very small so they are fully disintegrated into the plasma.^{[citation needed]}

See also

• Pulsed Energy Projectile
• Plasma torch
• Plasma antenna
• List of plasma (physics) articles

External links

• Jane's Defence Weekly article
• Plasma science and technology website
• The Register criticizes US plans to make a plasma weapon
• Russian plasma weapon