The particle physics collaboration group in the detector pit of the L-3 experiment at CERN's Large Electron-Positron Collider (LEP) ring during its construction in  (Sam Ting bottom left, in trench coat.) The pit now contains detectors that can measure and identify the various electrons, muons and photons that are emitted following collision events. The main part of the detector is the large magnet, contained in a cubic space of 12 meters each side and weighing 7810 tons. The magnet surrounds the particle detectors; the vertex chamber, the electromagnetic calorimeter, the hadron calorimeter and the muon chamber. The LEP ring was inaugurated on 13 November 1989.