Cyclotron in which the electric field is maintained at a constant frequency WordNet 3.0 & Open English WordNet

A synchrotron is a particular type of cyclic particle accelerator, descended from the cyclotron, in which the accelerating particle beam travels around a fixed closed-loop path. The magnetic field which bends the particle beam into its closed path increases with time during the accelerating process, being synchronized to the increasing kinetic energy of the particles. Wikipedia

Cyclic particle accelerator Wikidata

Cyclic particle accelerator in which the electromagnets, which control the speed and the trajectory of the particles being accelerated, are synchronized with the particle beam. OmegaWiki

A form of cyclotron in which charged particles are accelerated by an electric field that is synchronized with a magnetic field that keeps them in a circular path. Wiktionary

Form of cyclotron. Wiktionary (translation)