Jefferson Lab: Accelerator Physics

Illuminating collisions Within the US Department of Energy’s Jefferson Laboratory accelerator, known as the Continuous Electron Beam Accelerator Facility (CEBAF), a stream of millions of electrons races around an underground track nearly a mile in circumference. A billion times per second, magnets steer and focus the electrons into a beam the width of a human hair.

The accelerator is controlled and monitored by over one hundred computers that together track, manage and respond to more than 240,000 simultaneous signals and 40,000 hardware control points. Eventually, the electron beam is funneled to a trio of experimental halls, where the high-speed particles are slammed into target materials Scientists from around the world use the highly specialized electron beam produced by CEBAF to perform experiments that refine theories about how quarks, the small particles that combine to make protons and neutrons, behave in the nucleus. By measuring with great precision the properties of scattered particles after the electron beam collides with a target nucleus, scientists learn how quarks and the forces which hold them together interact and form the ordinary matter in the universe.