A plasma cannon (also called an electrothermal accelerator) is an experimental projectile weapon, which accelerates a projectile by means of a
plasma discharge between
electrode
An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit (e.g. a semiconductor, an electrolyte, a vacuum or a gas). In electrochemical cells, electrodes are essential parts that can consist of a varie ...
s at the rear of the barrel, generating a rapid increase in pressure. It functions similarly to other types of
firearms
A firearm is any type of gun that uses an explosive charge and is designed to be readily carried and operated by an individual. The term is legally defined further in different countries (see legal definitions).
The first firearms originated ...
, except that it uses a plasma discharge instead of a
chemical propellant (e.g.
black powder
Gunpowder, also commonly known as black powder to distinguish it from modern smokeless powder, is the earliest known chemical explosive. It consists of a mixture of sulfur, charcoal (which is mostly carbon), and potassium nitrate, potassium ni ...
or
nitrocellulose
Nitrocellulose (also known as cellulose nitrate, flash paper, flash cotton, guncotton, pyroxylin and flash string, depending on form) is a highly flammable compound formed by nitrating cellulose through exposure to a mixture of nitric acid and ...
).
Design
To generate the energy required to make a plasma discharge, a high current,
high voltage
High voltage electricity refers to electrical potential large enough to cause injury or damage. In certain industries, ''high voltage'' refers to voltage above a certain threshold. Equipment and conductors that carry high voltage warrant sp ...
source, and a large
capacitor
In electrical engineering, a capacitor is a device that stores electrical energy by accumulating electric charges on two closely spaced surfaces that are insulated from each other. The capacitor was originally known as the condenser, a term st ...
bank are used. Both are attached in series to the electrode system in the cannon's barrel. The capacitor is loaded with as high a voltage as possible. However, militarily useful energy is achieved with as little as several
kilojoule
The joule ( , or ; symbol: J) is the unit of energy in the International System of Units (SI). In terms of SI base units, one joule corresponds to one kilogram- metre squared per second squared One joule is equal to the amount of work don ...
s. The capacitor is then discharged. The gap between the electrodes
ionize
Ionization or ionisation is the process by which an atom or a molecule acquires a negative or positive charge by gaining or losing electrons, often in conjunction with other chemical changes. The resulting electrically charged atom or molecule i ...
s, turning the
non-flammable
A combustible material is a material that can burn (i.e., sustain a flame) in air under certain conditions. A material is flammable if it ignites easily at ambient temperatures. In other words, a combustible material ignites with some effort a ...
propellant medium into a
super heated conductive
plasma. Associated volumetric expansion propels the projectile from the barrel at high velocity.
Advantages and disadvantages
The advantage of a plasma cannon is that it uses electricity as its energy source. The more energy that is supplied the faster the gases expand and the faster the projectile can be accelerated. This makes it possible to "dial-in" any velocity desired and allows the projectile to reach a speed at which it would be possible to "outrun" the burn rate of a conventional propellant.
A clear disadvantage of the plasma cannon is its weight. Even a small plasma cannon with only the firepower of an
air gun
An air gun or airgun is a gun that uses energy from compressed air or other gases that are mechanically pressurized and then released to propel and accelerate projectiles, similar to the principle of the primitive blowgun. This is in contr ...
weighs about (without current supply). A foot soldier thus could not carry a plasma cannon powerful enough to be useful. It would have to be mounted in a stationary position or on a vehicle. It would be impossible for a soldier to carry a plasma cannon with the firepower of an actual cannon.
See also
*
Electrothermal-chemical technology
Electrothermal-chemical (ETC) technology is an attempt to increase accuracy and muzzle energy of future tank, artillery, and close-in weapon system guns by improving the predictability and rate of expansion of propellants inside the barrel.
An el ...
*
Plasma railgun
A plasma railgun is a linear accelerator which, like a projectile railgun, uses two long parallel electrodes to accelerate a "sliding short" armature. However, in a plasma railgun, the armature and ejected projectile consists of plasma, or hot, i ...
Further reading
*Günter Wahl: ''Blitz und Donner selbst erzeugt'' (in German)
Artillery
Plasma technology and applications
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