In conventional accelerators, energy from RF electromagnetic waves in vacuum is transformed into kinetic energy of particles driven by the electric field. In high-energy-physics colliders, some of that kinetic energy is in turn transformed into short-lived exotic particles. The new crown jewel of colliders is the recently completed Large Hadron Collider at CERN (see the Quick Study by Fabiola Gianotti and Chris Quigg in Physics Today, September 2007, page 90). The LHC, a 27-km-circumference ring for accelerating and storing countercirculating beams of 7-TeV protons, has a stored beam energy exceeding 300 MJ. The collider’s design luminosity (collision rate per unit scattering cross section) of 1034 s-1 cm-2 is two orders of magnitude greater than that of its immediate predecessor, the Tevatron collider at Fermilab.
Accelerator-based light sources rely on the fact that when beams of GeV electrons interact with magnetic fields or materials, they...
