Accelerators are ring-shaped or linear devices that accelerate charged particles. More powerful than any other microscope, high-energy accelerators allow physicists to study matter at the smallest scale human beings have ever seen, exposing the quarks inside a proton. At the same time, high-energy accelerators can produce collisions that recreate the conditions of the early universe – though in a much smaller volume. Creating tiny fireballs of high density and high temperature, physicists produce the particles that were abundant in the early universe, a trillionth of a second after the Big Bang. More. http://www2.slac.stanford.edu/vvc/accelerator.html
A device found in some semiautomatic firearms that, through mechanical advantage or spring energy, transfers kinetic energy from one part of the mechanism to another with the resultant speeding up of the action.