Particle propellor

A type of reactive engine used in spacecraft.

All engines work by expelling mass in one direction in order to accelerate the ship in the other. In order to reduce the mass they need to carry, these things accelerate it to a rediculous speed using a modified cyclotron setup before ejecting it. They normally take the shape of a bulky ring, with one or two exhaust ports expelling the matter tangentially to the ring.