The following “Facts” were taken from the sources quoted below. The Fictional section is my own interpretation and the summation is again my own interpretation based on the facts and fiction of Plasma as a weapon.

FACT:
What IS Plasma?
(1) There are three classic states of matter: solid, liquid, and gas; however, plasma is considered by some scientists to be the fourth state of matter because of its unique properties. Ionized refers to presence of one or more free electrons, which are not bound to an atom or molecule. The free electric charges make the plasma electrically conductive so that it responds strongly to electromagnetic fields.

Plasma typically takes the form of neutral gas-like clouds (e.g. stars) or charged ion beams, but may also include dust and grains (called dusty plasmas). They are typically formed by heating and ionizing a gas, stripping electrons away from atoms, thereby enabling the positive and negative charges to move more freely.

The Radio Instrument Building Research Institute under the supervision of Academician A. Avramenko developed a plasma weapon capable of killing any target at altitudes of up to 50 kilometers. Engineers and scientists of the institute in cooperation with the National Research Institute of Experimental Physics (Arzamas-16), Central Aerohydrodynamic Institute, and Central Machine Building Research Institute prepared a concept of the international experiment Doverie (Trust) for testing of the Russian plasma weapon at the American ABM testing ground in the Pacific Ocean together with the US. The cost of the experiment was estimated at $300 million. According to Academician Avramenko, the plasma antimissile weapon would not only cost tens times less than the American SDI, but would also be much simpler in development and operation. The offered joint project could save expenditures on development of its own plasma weapon for the US. The plasmoid based on the energy of ground super-high frequency generators or laser (optical) generators creates an ionized territory in the trajectory of a warhead and in front of it, and completely disrupts the aerodynamics of the object’s flight, after which a target leaves its trajectory and is ruined by monstrous overloads. The killing effect is delivered to the target at the speed of light.

How the use of Plasma weapons has an affect on the scientific community:
(2) Scientists have reacted angrily to the revelation that the US military is funding development of a weapon intended to deliver an “excrutiating bout of pain” from over a mile away. The “Pulsed Energy Projectile” (PEP) device “fires a laser pulse that generates a burst of expanding plasma when it hits something solid”, the New Scientist explains. If you happen to be that something solid, then you get temporarily incapacitated without suffering permanent injury.

Hand-held Plasma Weapons: 
(3) 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.

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, (Sound familiar) 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.
▪ 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.

This next part is very interesting as it also pretains to Railguns, of which we will see in Halo 4:
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.

(1) http://www.youtube.com/watch?v=uY1mn1IxFs8 11/24/2007
(2) http://www.theregister.co.uk/2005/03/03/us_plasma_weapon/ 3/3/2005
(3) http://en.wikipedia.org/wiki/Plasma_weapon

Another interesting link on the subject:
http://www.plasmas.org

Fiction (within Halo):
Plasma is used in varying forms within the Covenant. Most of them being weaponized. We have seen the plasma pistol, rifle, launcher; large ship mounted canons like those on the revenant, and wraith; as well as the huge cannons on Covenant vessels all the way from dropships to the massive capital ships.

Within the Haloverse plasma can be enabled to home in on a target. As noted above in the “Fact” section, this seems entirely plausible though not possible in our timeline. However, 500 years from now should be enough time for technology to progress so that there are homing plasma weapons.

In Halo we see plasma in differing colors. In the “Fact” section, it is noted that plasma would glow brightly, but does not specify what color. By using low grade color lasers (such as those in a laser pointer) it may be possible to “colorize” plasma to the desired color. In the case of Halo, this has somehow already been utilized.

Summation:
When comparing the factual side of Plasma as we know it today, vs. the fictional uses of Plasma in the Haloverse 500 or so years from now, there is a clear difference. However, it is likely that we will be able to harness the power of plasma for uses such as a handheld weapon. Given the advances of the scientific community in just the last 125 years, it is entirely plausible that plasma hand-held weapons will exist at some point, and likely BEFORE the time frame of the Halo franchise.

Plasma Weapons will need to make use of a powerful, yet small and mobile powersource, strong enough to create the force necessary to direct and maintain the plasma shot. Color laser pointers can be used in conjunction with the weapon to give it a specific color, however that would likely not be necessary and add weight to the design. Weapons such as these need not have color to them and the plasma would likely move too fast to see it anyway, especially over short distances. The only reason for a laser with the weapon at this point would be as a scope, which would not be seen except at the terminal point, (the target). Likewise the laser could be used as a directional device and mode of transportation for the plasma.

Yes, this article is long. However, if you stayed with me though the whole thing I commend you. I hope I’ve brought some real-world knowledge about Plasma to you and maybe even inspired you to look up more information on the subject. Look for more “The Science of Halo, Fact versus Fiction” articles in the near future. I’m currently writing up one for the Spartan Laser.

As always, thanks for reading and let me know what you think of the article.