Image of Aleph detector
One of the four detector systems built for the LEP accelerator (Large Electron-Proton). In this 27 km long ring at CERN electrons and positrons were accelerated in opposite directions to a velocity close to the velocity of light before colliding right in the center of the detector systems. The detector is designed to measure the momenta of charged particles, to measure the energy deposited in calorimeters by charged and neutral particles, to identify the three lepton flavors, and to measure the distance of travel of short-lived particles such as the tau lepton and the b and c hadrons.
Computer reconstruction of Z boson decaying into hadrons in the ALEPH detector