All accelerators are either linear or circular,
the difference being whether the
particle is shot like a bullet from a gun
(the linear accelerator) or whether the
particle is twirled in a very fast circle,
receiving a bunch of little kicks each
time around (the circular accelerator). Both types accelerate particles by
pushing them with an electric-field wave.
Linear accelerators (linacs) are used for fixed-target
experiments, as injectors to circular accelerators, or as linear colliders.
Injector to a circular accelerator:
The beams from a circular accelerator
(synchrotron) can be used for
colliding-beam experiments or
extracted from the ring for fixed-target experiments:
Extracted to hit a fixed target:
The particles in a circular accelerator go around in circles because large
magnets tweak the particle's path enough to keep it in the accelerator.
How do a
magnets make particles go in a circle?