particle accelerator

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A device, such as a cyclotron or linear accelerator, that accelerates charged subatomic particles or nuclei to high energies for the purpose of colliding them with other particles or targets.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Physics) A large and expensive scientific instrument used by physicists to accelerate elementary particles (such as protons or electrons) to speeds near that of light, for the purpose of investigating the fundamental properties of matter; sometimes also called an atom smasher, since the particles thus accelerated are often directed at targets of atoms which are fragmented by the impact into their more fundamental component particles.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A device that accelerates electrically charged particles to extremely high speeds, for the purpose of inducing high energy reactions or producing high energy radiation.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a scientific instrument that increases the kinetic energy of charged particles