CEBAF

The Continuous Electron Beam Accelerator Facility is located in a tunnel about 25 feet below ground. The oval-shaped tunnel is about 7/8 of a mile long. The tunnel is about 14 feet across and 10 feet high. Its concrete walls, floor and ceiling are about 21 inches thick. Magnets are used to direct the electron beam around the two arcs of the oval. This allows the beam to circulate up to five times before being directed into an experimental hall. With each lap around the accelerator, the beam gains additional energy.