Overview
- The Large Hadron Collider was taken offline Monday, June 29, 2026, as CERN began a planned four-year shutdown to transform the machine into the High-Luminosity LHC.
- Engineers will remove and replace about 1.2 kilometres of accelerator components and a large share of superconducting magnets to raise collisions per beam crossing from roughly 60 to about 140–200.
- CERN says the upgrade will vastly increase Higgs production from about 55 million to an expected ~380 million total, enabling searches for rare processes and physics beyond the Standard Model.
- The project, reported at about 1.2 billion Swiss francs, will also overhaul detector electronics and deploy real-time AI systems to pick which of the billions of collisions per second are saved for study.
- CERN plans initial upgraded tests as early as 2028, full readiness by mid-2030, a further extended shutdown around 2033, and operation of the LHC family until the Future Circular Collider phase begins around 2041.