The Low Energy Anti-Proton Ring (LEAR) was a particle accelerator at CERN which operated from 1982 until 1996. The ring was designed to decelerate and store

antiproton The antiproton, , (pronounced ''p-bar'') is the antiparticle of the proton. Antiprotons are stable, but they are typically short-lived, since any collision with a proton will cause both particles to be annihilated in a burst of energy. The exis ...

s, to study the properties of antimatter and to create atoms of antihydrogen. Antiprotons for the ring were created by the CERN Proton Synchrotron via the Antiproton Collector and the

Antiproton Accumulator The Antiproton Accumulator (AA) was an infrastructure connected to the Proton–Antiproton Collider (SpS) – a modification of the Super Proton Synchrotron (SPS) – at CERN. The AA was built in 1979 and 1980, for the production and accumulati ...

. The creation of at least 9 atoms of antihydrogen were confirmed by the PS210 experiment in 1995. In 1996, LEAR was converted into the Low Energy Ion Ring, which has since been used in the

lead Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cu ...

ion An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conve ...

injection process for the Large Hadron Collider. Low energy antiproton research continues at CERN using the

Antiproton Decelerator The Antiproton Decelerator (AD) is a storage ring at the CERN laboratory near Geneva. It was built from the Antiproton Collector (AC) to be a successor to the Low Energy Antiproton Ring (LEAR) and started operation in the year 2000. Antiproto ...

. It was built as a successor for LEAR and started operation in 2000.

References

CERN accelerators Particle accelerators CERN CERN facilities Particle physics facilities {{particle-stub