The Yamato cannon (a.k.a. Yamato gun) is a feared[1]terran particle weapon.
By the Great War, recent research had led to the development of the weapon. It uses an intense magnetic field to focus a small nuclear explosion into a cohesive beam of energy. The cannon requires a huge energy of reserve to fire, but the effects make it worthwhile. In 2499, terran engineers were working overtime to retrofit existing battlecruisers with the weapon. Behemoth-class battlecruisers recieved such retrofits.[2]