is a type of a particle accelerator
involving directed beams of particles
Colliders may either be ring accelerators or linear accelerators.
In particle physics
one gains knowledge about elementary particles
by accelerating particles to very high kinetic energy
and letting them impact on other particles. For sufficiently high energy, a reaction
happens that transforms the particles into other particles. Detecting these products gives insight into the physics
To do such experiments there are two possible setups:
- Fixed target setup: A beam of particles (the projectiles) is accelerated with a particle accelerator, and as collision partner, one puts a stationary target into the path of the beam.
- Collider: Two beams of particles are accelerated and the beams are directed against each other, so that the particles collide while flying in opposite directions.
The collider setup is harder to construct but has the great advantage that according to special relativity the energy of an inelastic collision between two particles approaching each other with a given velocity is not just 4 times as high as in the case of one particle resting (as it would be in non-relativistic physics); it can be orders of magnitude higher if the collision velocity is near the speed of light.