ALEPH experiment

[1][2][3] The ALEPH detector was built to measure events created by electron positron collisions in LEP.

The iron return yoke was a dodecagonal cylinder with two end-plates that left holes for a focusing magnet (quadrupole) of the LEP machine.

[4] Inside the coil was the electron-photon calorimeter (ECAL), designed for the highest possible angular resolution and electron identification.

It consisted of alternating layers of lead and proportional tubes read out in 73,728 projective towers, each subdivided into three depth zones.

The central detector for charged particles was the time projection chamber (TPC), 4.4 m long and 3.6 m in diameter.

The ALEPH detector had a time projection chamber at its core for detecting the direction and momenta of charged particles with extreme accuracy. In the foreground from the left, Jacques Lefrancois, Jack Steinberger , Lorenzo Foa and Pierre Lazeyras. ALEPH was an experiment on the LEP accelerator, which studied high-energy collisions between electrons and positrons (1989-2000)