What is the X in X-mas?
A type of particle accelerator that accelerates charged subatomic particles (generally protons) in a circular path. Unlike cyclotrons and synchrocyclotrons, in which particles follow a spiral path, synchrotrons consist of a single ring-shaped tube through which the particles loop numerous times, guided by precisely synchronized magnetic fields and accelerated at various points in the loop by electric field bursts. Synchrotrons are currently the most powerful particle accelerators, and the study of high-energy collisions driven by synchrotrons has lead to the discovery of many subatomic particles. See also cyclotron, synchrocyclotron. See Note at particle accelerator.