CERN has powered down the Large Hadron Collider (LHC), marking the end of its current operational era and the beginning of an ambitious four-year upgrade program.
After nearly two decades of groundbreaking discoveries, including the confirmation of the Higgs boson in 2012, the world’s most powerful particle accelerator has entered a planned shutdown phase known as Long Shutdown 3. The final run concluded in June 2026, with proton collisions reaching energies of 13.6 teraelectronvolts.
The upgrade will transform the LHC into the High-Luminosity Large Hadron Collider (HL-LHC), a next-generation system designed to dramatically increase collision rates. CERN is investing approximately 1.2 billion Swiss francs (around $1.5 billion) into the project, which involves extensive modifications across sections of the 27-kilometer ring. Engineers will install advanced superconducting magnets and specialized “crab” cavities to refine particle beam alignment and boost performance.
Once operational, the HL-LHC is expected to increase luminosity by up to ten times, allowing scientists to collect significantly more data and conduct higher-precision experiments. This will deepen our understanding of the Higgs boson and expand the search for new physics, including candidates for dark matter and other phenomena beyond the Standard Model.
The upgraded collider is scheduled to come online in 2030 and is expected to operate for at least another decade, extending the LHC’s scientific mission into the 2040s. In the meantime, researchers will continue analyzing data from the final run, while parts of CERN’s broader accelerator complex are set to resume operations as early as 2028.
Rather than an ending, CERN describes this moment as a transition — one that positions the LHC for its most productive phase yet.
