CERN's Proton Synchrotron - now (and then)

1 December 1999



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The Proton Synchrotron (PS) at CERN, the European Laboratory for Particle Physics near Geneva, is now 40 years old, but still running strong. Although it began life as the world's highest energy particle accelerator, the PS continues to this day to play a key role as an injector to CERN's bigger accelerators. This image from 1996 shows the dipole magnets that guide the particle beam around the 200-m diameter ring. ( Click here for a similar image from 1959.) Designed for protons, the PS has also accelerated antiprotons, electrons, positrons and heavy ions - nuclei of large atoms such as lead. It has even operated as a decelerator, slowing down antiprotons for injection into the Low Energy Antiproton Ring (LEAR). Its multitalented capacity will continue into the 21st century, when it will provide protons and heavy ions for CERN's new Large Hadron Collider (LHC).

Credit: CERN Photo