Ionic fusion bar

An ionic fusion bar was the power core of a ship that crashed at Roswell in 1947.

Function
The ionic fusion bar served as the main power supply for the ship which the Grey aliens flew. (TV: Dreamland) Without it, the ship could not take off. (TV: Prisoner of the Judoon)

History
In 1947, an alien ship crashed in Roswell. The ionic fusion bar ended up in a diner in which Cassie Rice worked. The Tenth Doctor found it and took it, keeping it safe from the Alliance of Shades. The ship had been taken to the Dreamland base, but would not work, as it was lacking the bar. The Doctor used the ship, placed the bar in its place and escaped. (TV: Dreamland) Later, Androvax recreated the ship and fusion bar using nanoforms. Luke Smith used it as a bargaining chip so Androvax would release his mother, as the ship could not take off without it. The Judoon later took it with them when they took control of the ship. (TV: Prisoner of the Judoon)