from
The Collaborative International Dictionary of English v.0.48
Particle accelerator \Par"ti*cle ac*cel"er*a*tor\, n. (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.
Note: The particles generated by impact of a beam in an
accelerator on its target are detected by various types
of detecting apparatus, and procedures are required to
sort and identify the many particles created. The
fundamental particles generated by impacts in a
particle accelerator are often those not actually
present inside atoms; and in certain types of particle
accelerator, such as the {colliding beam accelerator},
the impact which generates energetic particles is with
other fundamental particles, and not with atoms.
[PJC]