Plasma

In physics and chemistry, Plasma is a partially ionized gas, in which a certain proportion of electrons are free rather than being bound to an atom or molecule. The ability of the positive and negative charges to move somewhat independently makes the plasma electrically conductive so that it responds strongly to electromagnetic fields. Plasma therefore has properties quite unlike those of solids, liquids or gases and is considered to be a distinct state of matter. Plasma typically takes the form of neutral gas-like clouds, as seen, for example, in the case of stars.

Function
Though difficult to control, the Covenant military and Forerunner Constructs use plasma in a weaponised form to great effect, containing and guiding it in the form of a single bolt, or a continuous stream, or superheated gas. Plasma-based weapons are the most common armament of Covenant infantry and vehicular forces, and are the main armaments of their warships. Smaller weapons are designed to deplete shielding or melt infantry armor, while heavier weapons can destroy vehicles or buildings. The largest are mounted to capital ships, and are used for orbital bombardment and ship-to-ship combat. When the a plasma weapon is charging a shot, high quantities of beta particle radiation are emitted. Humans use plasma as an energy source and to cut heavy metals in factories, but have yet to weaponise it for use in their armed services, relying on projecile weaponry.

Plasma weapons likely work with a high temperature pilot flame and a high power electromagnet, stripping the plasma out of the flame, and projecting it forward. This trades off the extra damage of fire for the added range and lack of dependence, on an atmosphere. Alternatively, plasma weapons could work by super-charging a fuel gas into a plasma by electrical discharge or a laser. The plasma is then harnessed and accelerated out of the weapon electromagnetically at high velocities. In either concept, the plasma would need to be stabilized by some mechanism to prevent it from dispersing immediately at the slow speed plasma bolts move.

Starship Weaponry

 * Plasma Torpedo
 * Plasma Turret
 * Plasma Charge

Vehicles

 * Scarab
 * Seraph
 * Banshee
 * Wraith
 * Spectre
 * Phantom
 * Ghost
 * AA Wraith

Weapons

 * Automated Plasma Cannon
 * Plasma Mortar
 * Twin Plasma Cannons

Explosives

 * Plasma Grenade

Firearms

 * Energy Sword
 * Plasma Rifle
 * Plasma Pistol
 * Brute Plasma Rifle

Turrets

 * Shade


 * Plasma Cannon

Trivia
プラズマ
 * Human users can contract Boren's Syndrome from prolonged contact to the radiation emitted by plasma grenades.
 * For gameplay reasons, plasma is less lethal to unshielded NPCs in the Halo games than in the novels. In the games, Marines can take a barrage from a plasma weapon without being incapacitated, but in the books there are several incidences of plasma easily burning through both armor and flesh.
 * It seems that the power of the gun depends on what colour the plasma gun is. For example the Plasma Pistol shoots out green plasma but the weapon is not very powerful, the Plasma Rifle shoots blue plasma which is more powerful, the Brute Plasma Rifle shoots red plasma which is slightly more powerful than blue plasma, while the forward turret on a Phantom in Halo 3 shoots out purple plasma which is the most powerful.
 * In the books, it says that plasma torpedoes could rip through the armor of a UNSC ship with one hit. In Halo: Combat Evolved and The Flood, the UNSC Pillar of Autumn managed to take several hits and remain reasonably intact. However, the honeycombed design of the ship's hull allowed it to sustain up to a ninety-percent loss of hull integrity.