Large Hadron Collider

Location Large Hadron Collider

LHC quadrupole magnets

CERN LHC Proton Source

View inside detector at the CMS cavern LHC CERN

Lyn Evans - pictures donated by CERN-1 (cropped)

Large Hadron Collider

The Large Hadron Collider (LHC) is the world's largest and highest-energy particle accelerator designed and built by the European Organization for Nuclear Research (CERN) near Geneva, in Switzerland. Situated underground, it spans the border between Switzerland and France. The LHC's main aim is to explore the physics of the smallest particles by colliding protons or heavy ions at close to the speed of light. This massive scientific instrument was constructed to test various predictions of high-energy physics, including the existence of the hypothesized Higgs boson and of the large family of new particles predicted by supersymmetric theories.

Design and Construction

The LHC is a circular accelerator, housed in a tunnel with a circumference of 27 kilometers (17 miles). The tunnel, lying as deep as 175 meters (574 feet) beneath the surface, was originally built for the Large Electron-Positron Collider (LEP) which was decommissioned in 2000. The LHC consists of a ring of superconducting magnets with a number of accelerating structures to boost the energy of the particles along the way.

Operational History

The LHC was officially started up on 10 September 2008, with the first proton-proton collisions being recorded on 30 March 2010. It operates at energies up to 13 teraelectronvolts (TeV), making it the highest energy particle collider in the world. The LHC's experiments have led to significant scientific breakthroughs, including the discovery of the Higgs boson in 2012, a fundamental particle associated with the Higgs field, which gives other particles their mass.

Experiments and Discoveries

Several major experiments are conducted at the LHC, located around different points of the collider ring. These include ATLAS, CMS, ALICE, and LHCb. Each experiment is designed to research different aspects of particle physics. The discovery of the Higgs boson by the ATLAS and CMS collaborations was a monumental achievement, confirming a key part of the Standard Model of particle physics. The LHC has also provided valuable insights into the quark-gluon plasma, a state of matter that existed shortly after the Big Bang.

Future Plans

CERN has plans to upgrade the LHC to increase its luminosity, referred to as the High-Luminosity LHC (HL-LHC). This upgrade aims to enhance the collider's potential for discovery by increasing the number of collisions tenfold and allowing for a more detailed study of rare processes. The HL-LHC is expected to start operations around 2027.

Impact

The LHC has had a significant impact on physics, technology, and society. It has advanced our understanding of the universe at the smallest scales, contributed to the development of new technologies, and fostered international collaboration in science. The data generated by the LHC experiments are also used to test the limits of the Standard Model and to search for new physics beyond the Standard Model, including dark matter and extra dimensions.