The Large Hadron Collider is the world's largest and most powerful particle accelerator. The 26.7-kilometer (16.6-mile) underground ring is located on the border between France and Switzerland and was built to test fundamental theories in particle physics. The name comes from the accelerator colliding protons or ions composed of protons and neutrons—both are classified as hadrons—at near-light speed, producing showers of particles that can be compared to predictions.
> The LHC repurposed an excavation tunnel built for the Large Electron-Positron Collider, once Europe's largest civil engineering project. (More)
> Research at the LHC generates an estimated $1.2 for every $1 spent. (More)
Before a collision occurs, gas molecules are stripped of electrons using an electric field. A series of smaller accelerators increases the speed of the resulting ions, which are then sent in opposite directions down two LHC pipes, whose vacuum conditions resemble those on the lunar surface. Electromagnets cooled by liquid helium to temperatures lower than those in outer space accelerate and guide these particles into collisions—where temperatures can reach 5.5 trillion Kelvin—at one of four detector sites along the ring.
> Watch an animated visualization of how the accelerator complex works. (More)
> Data from the LHC is managed by a system with 2 billion gigabytes of storage spread out across more than 40 countries. (More)
As of 2026, the LHC has discovered 86 particles, including the Higgs boson, which, according to the Standard Model, is responsible for the masses of fundamental particles. In 2026, the accelerator will begin a multiyear shutdown and be upgraded to the High Luminosity Large Hadron Collider to improve collision rates.
> How does the Higgs boson provide particles with mass? (More)
> See the collection of Champagne bottles from parties celebrating major LHC milestones. (More)
Discover more:
> At the LHC, scientists have transformed lead into gold—a process known as chrysopoeia. (More)
> Despite what you've heard, the LHC does not create planet-destroying black holes. (More)
> Earlier this year, the LHC provided heat to thousands of French homes and businesses through a heat exchanger system. (More)
