Plasma Destructor

The Plasma Destructor is a large Plasma Weapon employed by Reaver-class, Warlord-class and Imperator-class Titans. This deadly weapon possesses formidable firepower over a large area than most other types of weapons. When a target is hit the tremendous heat and energy released destroys the target in an almighty explosion. When it strikes a target the searing heat and explosive shock of a plasma bolt's substance is instantly energised into boiling plasma. Though a highly effective weapon system, it tends to lose accuracy over long range, and require a massive amount of energy to power it.

Operation
When a Plasma Destructor is fired, the fuel is energized into plasma and unleashed as brightly glowing "bolts" of pure energy. These bolts are ncased in a magnetic containment field that prevents the plasma "bolt" from dissipating before reaching its target. Once the plasma comes into contact with a solid material, the magnetic field ruptures, venting the superheated energy onto the target. The enemy is then vaporised. The drawback of such a powerful weapon is that it is usually extremely dangerous to deal with plasma. Most Imperial Plasma Weaposn are very unstable due to their less-than-perfect designs as a result of the technological decline over millennia. To prevent overheating, a plasma weapon must vent its excess heat into the surrounding area due to a lack of a sufficient cooling apparatus. Even with such a countermeasure in place, sometimes these plasma weapons can still overheat and explode, destroying or severely disabling a Titan that employs this weapon system. When struck by enemy fire a plasma weapon can easily explode, killing all aboard.

Source

 * Adeptus Titanicus (1st Edition)
 * Apocalypse
 * Titanicus (Novel) by Dan Abentt
 * Warhammer 40,000 Weaponry (2nd Edition)