What is an accelerator?
An accelerator is a device used to make something go faster. Jefferson Lab's accelerator is a racetrack-shaped machine used to make electrons travel at nearly the speed of light.
Jefferson Lab's accelerator is about 1.4 kilometers around (about 7/8 of a mile) and was built in a tunnel 8 meters (about 25 feet) underground. Electrons gain energy as they pass through the straight sections of the accelerator and are steered by large electromagnets as they pass through the curved sections. An electron can travel around the accelerator as many as five times, gaining energy with each trip. Once an electron has enough energy, which can be as much as 6 billion volts, it is directed to one of the three large, hill-like experimental halls where it collides with the target.