European Organization for Nuclear Research

CERN: View of CMS detector

View of CMS detector

CERN's main duty is to design, build and operate very complex machines called particle accelerators where physicists collide minute particles of matter to unravel the basic laws of nature. This research is purely scientific and the results are freely available. The laboratory's accelerator complex is built around three principal interconnected accelerators. The oldest, the Proton Synchrotron (PS), was built in the 1950s and was briefly the world's highest energy accelerator. The Super Proton Synchrotron (SPS), built in the 1970s, was the scene of CERN's first Nobel prize in the 1980s. The Large Electron-Positron collider (LEP), which started up in 1989, finished operation in November 2000 after contributing a very accurate study of the electronpositron collisions and thus providing a profound knowledge of the weak interaction, one of the four interactions in nature.

CERN has completed the installation of a new accelerator inside the same tunnel as LEP - a 27-kilometre underground ring - called the Large Hadron Collider (LHC). This machine is arguably the most complex scientific instrument ever constructed, and will give the world's physicists a new tool to probe deeper than ever into the heart of matter. The first collisions took place in 2010. Since then, the LHC has increased the intensity of its beams to their nominal values, and is now running with a collision energy of 8 TeV. 

CERN: View of the LHC accelerator in the tunnel

View of the LHC accelerator in the tunnel

Each of CERN's accelerators hosts a range of experiments run by collaborations of physicists from around the world. Currently, CERN has some 11 000 users - people of 104 nationalities representing more than 500 universities who come to the Laboratory to use its facilities and participate in its experiments.

From material science to computing, particle physics demands the ultimate in performance, making CERN an important test-bed for industry. Today everyone knows the World Wide Web, but not many know that it was invented at CERN, conceived to give particle physicists easy access to their data wherever they happened to be on the planet. The World-Wide Web, the Grid, medical imaging, and advanced techniques for using electronic chips are just a few of the many recent spinoffs from the fundamental research done at CERN.