CERN's Large Hadron Collider has collided its last hadron. The 27-kilometer (17-mile) ring, buried dozens of meters underground on the French and Swiss border, begins decommissioning today. The collider will not be dismantled, but upgraded as the High Luminosity Large Hadron Collider—a project that will take several years.
"So long #LHC and thank you for all the collisions," CERN, the European Organization for Nuclear Research, posted on social media. "Today, the Large Hadron Collider (LHC), the world's most powerful particle accelerator, comes to the end of an extraordinary chapter in its scientific journey."
Following its final physics run, the accelerator has been switched off to begin CERN's Long Shutdown 3 (LS3), a major programme of maintenance, consolidation, upgrades and installation work that will prepare the Laboratory for the High-Luminosity LHC (HiLumi LHC), the next phase in the exploration of the fundamental laws of nature.
Since circulating its first beams in September 2008, the LHC has pushed the frontiers of science and technology, becoming one of the most ambitious scientific instruments ever built. The accelerator delivered its first proton collisions in 2009 and rapidly established itself as a unique discovery machine – across three operational periods (Runs 1–3), the LHC delivered unprecedented quantities of data to its experiments.
CERN built the facility between 1998 and 2008 to test predictions made in theoretical physics about the behavior of tiny particles. The first collisions were achieved in 2010 at an energy of 3.5 tera-electronvolts (TeV) per beam, smashing previous records. Within two years it confirmed the existence of the Higgs boson, the particle tied to the field that gives other particles mass, first predicted in 1964. This gave strong experimental backing to the Standard Model of physics. Peter Higgs and François Englert won the 2013 Nobel Prize in physics.
"The LHC has exceeded every expectation," said Oliver Brüning, CERN Director for Accelerators and Technology, in a press release. "For nearly two decades, it has transformed our understanding of the Universe and inspired generations of scientists, engineers and citizens around the world. Today we say goodbye to the LHC as we have known it, while preparing to welcome its successor: the HiLumi LHC, which will extend this scientific adventure far into the future."
Other findings include new composite particles such as tetraquarks and pentaquarks, which contain four or five quarks rather than the usual two or three, and Quark-gluon plasma.
Previously:
• $39K gets you authentic piece of the Large Hadron Collider
• Quilts inspired by the Large Hadron Collider
• How To: Assemble a large hadron collider
• Large Hadron Collider: Now This Is Just Getting Ridiculous
• What would happen if you stuck your hand into the Large Hadron Collider?
• CERN scientists release 300 terabytes of Large Hadron Collider data, free and open
• Large Hadron Collider probably won't destroy Earth
• 3 Things the Higgs Boson can teach you about physics
