Overview
- The Large Hadron Collider was switched off on June 29, 2026, to start Long Shutdown 3 and begin work converting the facility into the High‑Luminosity LHC (HiLumi).
- Teams will remove and replace about 1.2 km of accelerator components and install stronger superconducting magnets and crab cavities to sharpen the proton beams.
- ATLAS and CMS detectors will be extensively rebuilt and their trigger systems replaced so they can handle roughly 140–200 proton collisions per bunch crossing and select events from billions of interactions per second.
- CERN says the work will cost about 1.2 billion Swiss francs, involve thousands of specialists, include phased restarts from 2028, and aims for HiLumi operations around 2030.
- The upgrade should yield far larger datasets—about 380 million Higgs bosons over HiLumi’s run—letting researchers pursue precise Higgs measurements and rare‑event searches while many scientists continue analysing existing data and preparing experiments.