plasma, in physics, fully ionized gas of low density, containing approximately equal numbers of positive and negative ions (see electron and ion). It is electrically conductive and is affected by magnetic fields. The study of plasma, called plasma physics, is especially important in research efforts to produce a controlled thermonuclear reaction (see nuclear energy). Such a reaction requires extremely high temperatures; it has been computed that a temperature of about 10 million degrees Celsius would be needed to initiate the reaction between deuterium and tritium. By passing a very high electric current through plasma great heat is produced and, simultaneously, an electromagnetic field is created, causing the plasma to withdraw from the walls of its container. The contraction of the plasma, called the pinch effect, prevents the container from being destroyed, but the effect may become unstable too quickly for the fusion reaction. The properties of plasma are distinct from those of the ordinary states of matter, and for this reason many scientists consider plasma a fourth state of matter. Interstellar gases, as well as the matter inside stars, are thought to be in the form of plasma, thus making plasma a common form of matter in the universe. See also condensate.

plasma, biological: see blood.

Any of a major class of proteins insoluble in pure water and soluble in dilute saline (salt) solutions. In their natural state, the protein chain is folded into a globular form. Globulins are found in many plants, especially cereals. Globulins in animal fluids include enzymes, antibodies (the gamma globulins), lipoproteins, complement components, transport proteins, and various types of fibrous and contractile proteins.

Learn more about globulin with a free trial on Britannica.com.

Subgroup of the globulins. In humans and many other mammals, most antibodies are in the gamma globulin fraction of blood. A human gamma globulin preparation may be administered (by injection) to persons lacking immunity, either generally or to a particular disease, after exposure or before expected exposure.

Learn more about gamma globulin with a free trial on Britannica.com.

A malignant proliferation of abnormal plasma cells that populate the marrow-containing bones of the body. The affected plasma cells produce myeloma protein, a monoclonal antibody that replaces normal antibodies in the blood, thereby increasing susceptibility to infection and renal failure. Symptoms include pain, anemia, weakness, infection, a tendency to hemorrhage, shortness of breath, kidney insufficiency, bone fractures, and neurological symptoms. It is considered a progressive and incurable disease; treatments with thalidomide, bone-marrow transplantation, and high-dose chemotherapy may extend life span, although success rates are variable.

Learn more about multiple myeloma with a free trial on Britannica.com.

Electrically conducting medium in which there are roughly equal numbers of positively and negatively charged particles, produced when the atoms in a gas become ionized (see ionization). Plasma is sometimes called the fourth state of matter (the first three being solid, liquid, and gas). A plasma is unique in the way it interacts with itself, with electric and magnetic fields, and with its environment. It can be thought of as a collection of ions, electrons, neutral atoms and molecules, and photons in which some atoms are being ionized at the same time as electrons are recombining with other ions to form neutral particles, while photons are continuously being produced and absorbed. It is estimated that more than 99percnt of the matter in the universe exists in the plasma state.

Learn more about plasma with a free trial on Britannica.com.

Plasma-based weaponry is any group of weapons designed to use high-energy ionized gas or "plasma", typically created by superheating lasers or superfrequency devices. There has been notable interest in its development. One plasma prototype weapon exists in Russia which was developed by The Radio Instrument Building Research Institute under the supervision of Academician A. Avramenko. Their action is based on focusing beams of electromagnetic energy produced by laser or microwave radiation into the upper layers of the atmosphere.

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 travelling 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.

While both of these proposals are scientifically feasible, practical applications are beyond our current level of technology. However, the Russians have stated to have developed a so-called "bolt-on" plasma generator that is used to actually increase the aerodynamic performance of their research aircraft using plasma to influence the fluid dynamics.

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 a whole lot 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 shockwave inside the plasma ball, creating a flash of light and explosion.

HAARP

An Air Force research project to study atmospheric phenomenon but invokes many conspiracy theories because of its high power consumption and potential as a radio frequency based weapon.

Science-fiction

Much science-fiction literature as well as movies and computer games has references to plasma weaponry.

Examples:

• The British sci-fi series Blake's 7
• The sci-fi universe Warhammer 40,000
• The free online multiplayer game OGame
• The Halo video game series
• The Terminator movie series
• The Metroid video game series
• The sci-fi toy line and anime series Zoids
• The Doom video game series
• The Combine's synths use plasma-based weaponry in Half-Life 2
• The X-Com video game series
• The Matrix series features plasma weaponry

See also

• Pulsed Energy Projectile, an experimental non-lethal weapon technology that involves emission of a laser pulse that creates a small amount of exploding plasma upon contact with the target
• Plasma torch
• Plasma rifle

References

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
• Star Wars vs. Star Trek Essays: Plasma Weapons