Mass Effect 2:
Following the Battle of the Citadel, human and turian volunteers conducted a massive three-month recovery effort to clear the station's orbit of debris. Secretly, the turian Office of Technological Reconnaissance "volunteers" were technology recovery specialists salvaging the main weapon of the geth flagship Sovereign, and large amounts of its valuable element zero core.
Contrary to popular belief, Sovereign's main gun was not a directed-energy weapon. Rather, its massive element zero core powered an electromagnetic field suspending a liquid iron-uranium-tungsten alloy that shaped into armor-piercing projectiles when fired. The jet of molten metal, accelerated to a fraction of the speed of light, destroys targets by impact force and irresistible heat.
Only 11 months after the battle, the turians produced the Thanix, their own miniaturized version of Sovereign's gun. The Thanix can fire reliably every five seconds, rivaling a cruiser's firepower but mountable on a fighter or frigate.
Mass Effect 3:
After the Battle of the Citadel, human and turian volunteers spent three months clearing the station's orbit of debris. During the cleanup, the turians secretly salvaged Sovereign's powerful main gun along with much of the weapon's element zero core. Eleven months later, the turians introduced the Thanix, a scaled-down version of the weapon.
The Thanix's core is a liquid alloy of iron, uranium, and tungsten suspended in an electromagnetic field powered by element zero. The molten metal, accelerated to a significant fraction of the speed of light, solidifies into a projectile as it is fired, hitting targets with enough force to pierce any known shield or armor. The gun can fire reliably every five seconds.
The weapon's relatively small size allows it to be mounted on most fighters or frigates. It is now widely used by the Alliance military and is the primary weapon on the refurbished Normandy SR-2.