Particle accelerators are devices that use electromagnetic fields to propel charged particles to high speeds and to contain them in well-defined beams. They are used in a wide range of scientific research disciplines including paericle physics, materials science, and medicine.
The largest accelerators can be sevral kilometers long and are used for
fundmental research into the structure of matter. Smaller accelerators are
used in a wide variety of applications, include particle therapy for
treating cancer.
The one shown above is the reknown Large Hadron
Collider (LHC) at CERN.
It's objectives are to test various
predictions of high-energy physics, including the existence of the
Higgs boson
and of the large family of new particles predicted by supersymmetric
theories, as well as other unsolved questions of physics.