Proton Synchrotron (PS)

The Proton Synchrotron (PS) is the first major particle accelerator at CERN, built as a 28 GeV proton accelerator in the late 1950's and put into operation in 1959. It takes the protons from the Proton Synchrotron Booster at a kinetic energy of 1.4 GeV and lead ions from the Low Energy Ion Ring (LEIR) at 72 MeV per nucleon. It has been operated as an injector for the Intersecting Storage Rings (ISR), the Super Proton Synchrotron (SPS) and the Large Electron-Positron Collider (LEP). Starting in 2008, the PS machine will deliver protons and lead ion beams for the Large Hadron Collider (LHC).

The PS machine is a circular accelerator with a circumference of 628.3 m. It is an extremely versatile machine having accelerated protons, antiprotons, electrons, positrons and various species of ions. Major upgrades have improved its performance by more than a factor of 1000 since 1959. The only main components remaining from its original installation some 50 years ago are the bending magnets and the buildings.