Molecular disperser
The Molecular disperser was a piece of technology employed by the Silurians.
This device was capable of dispersing the Van Allen belt around a planet allowing for radiation to directly damage the world thus making it uninhabitable. After the Humans, through the aid of The Doctor, discovered a cure for the Silurian plague, the new leader decided to employ the disperser as a different way of exterminating the Human race.
However, the machine required a great deal of power which they believed they would gain through a Human power station that they were draining power from. It appeared as a barrel shaped machine which required two Silurians to carry. Once connected to a power source, it was able to convert nuclear energy into microwave rays which disperse the molecules of the filter that protects the world. The Silurians were capable of controlling the process in order to ensure it did not go out of control and thus destroy the planet. (DW: Doctor Who and the Silurians)