An offshoot of plasma torpedoes, the plasma cannon is a close range, hard hitting direct fire weapon. Instead of relying on energy beams (like laser or particle accelerators), or graviton projectors (more commonly referred to as “force” beams), the plasma cannon instead launches packets of high-temperature plasma contained in a kind of “static drive field” to maintain coherence over combat ranges.
In order to understand what makes a plasma cannon an effective weapon, a few words have to be said on how they operate.
Plasma cannons are mechanically quite simple in operation. Feedstock is usually a Hydrogen/Argon mix, contained in separate tanks but mixed as part of the loading process. While the cannons are usually designed to draw off a ship’s power mains, their comparatively low power draw allows them to have a local auxiliary power array that is capable of completely servicing the weapon mount (usually via a capacitor bank). The feedstock is injected into the charging chamber, which is then pumped with energy from the capacitors. Powerful magnets help contain the resulting plasma. While this is happening the mount stabilizes on its target and awaits a fire command. When given, a pair of miniature drive field coils wrapped around the main barrel overlay a static drive field on the mass of plasma, before it is ejected in the direction of the target.
This static drive field is the main source of the plasma cannon’s drawbacks (and its strengths). The biggest drawbacks are its poor range and accuracy compared to other direct energy weapons. The former is a result of the poor lifespan of a static drive field, which results in the packet dissipating harmlessly at range. The latter is a result of how said field decays unevenly, which results in the plasma packets “wobbling” downrange. But the relative simplicity of the whole system makes for a compact weapon (meaning more mounts-per-ton), and the “wobble” paradoxically means that the packets are harder to spoof via drive field modulation.
What this means is that at close ranges, and in complex ECM environments, the plasma cannon makes for a devastating weapon, capable of delivering colossal damage in a short time. A warship engaging its target with multiple cannons is often likened to an old ship-of-the-line from the age of sail, with multiple batteries laying heavy, rapid fire into a target. Few ships can hope to survive a close engagement with a main battery of plasma guns, but outside these specific engagement parameters, that same warship will find itself outranged and unable to reply in kind.
The current manufacturer of 90% of plasma weapons (torpedo and cannon) is Subach-Witzig, based on the planet Witzig. It has, over the years, developed a full line of plasma-based ordinance, ranging from starship grade weapons such as the aforementioned plasma cannons to small squad and handheld weapon systems. Like Royal Magnetics of Ibiza, Subach-Witzig is the undisputed leader in their field of business.