The ion cannon was a new development made by scientists of the Klingon Empire, a ship-mounted directed energy weapon utilizing ion technology, outfitted on the Klingon Negh'Var-class heavy carriers. The weapon fired a single powerful burst of energy that did a great deal of damage to enemy targets, however, once used it would take some time before the necessary power levels were restored for the weapon to be used again. (TNG game: Armada)