1. An accelerator in which particles are propelled in spiral paths by the use of a constant magnetic field.
2. A circular particle accelerator in which charged subatomic particles generated at a central source are accelerated spirally outward in a plane perpendicular to a fixed magnetic field by an alternating electric field.

A cyclotron is capable of generating particle energies between a few million and several tens of millions of electron volts.

3. An accelerator that imparts energies of several million electron-volts to rapidly moving particles.