Large Hadron Collider

A bird’s eye view of the LHC
(Credit: CERN)

The Large Hadron Collider (LHC) is by far the most powerful particle accelerator built to date. Following an upgrade, the LHC now operates at an energy that is 7 times higher than any previous machine! The LHC is based at the European particle physics laboratory CERN, near Geneva in Switzerland. CERN is the world’s largest laboratory and is dedicated to the pursuit of fundamental science.

Evolution of the universe after the big bang
(Credit: CERN)

The LHC allows scientists to reproduce the conditions that existed within a billionth of a second after the Big Bang by colliding beams of high-energy protons or ions at colossal speeds, close to the speed of light. This was the moment, around 13.7 billion years ago, when the Universe is believed to have started with an explosion of energy and matter. During these first moments all the particles and forces that shape our Universe came into existence, defining what we now see.


Maintenance on the LHC beamline
(Credit: CERN)

The LHC is exactly what its name suggests - a large collider of hadrons (any particle made up of quarks). Strictly, LHC refers to the collider; a machine that deserves to be labelled ‘large’, it not only weighs more than 38,000 tonnes, but runs for 27km (16.5mi) in a circular tunnel 100 metres beneath the ground. Particles are propelled in two beams going around the LHC to speeds of 11,000 circuits per seconds, guided by massive superconducting magnets! These two beams are then made to cross paths and some of the particles smash head on into one another.

However, the collider is only one of three essential parts of the LHC project. The other two are:

  • The Detectors
    Each of the four main detectors sit in huge chambers around the LHC ring to detect the outcomes of the particles colliding. ATLAS, ALICE, CMS and LHCb.

  • Worldwide LHC Computing Grid (WLCG)
    A global network of computers and software that is essential to processing the masses of data recorded by all of the LHC’s detectors.
LHC Computing Grid Globe into the computer center
(Credit: CERN)

The LHC is truly global in scope because the LHC project is supported by an enormous international community of scientists and engineers. Working in multinational teams all over the world, they are building and testing equipment and software, participating in experiments and analysing data. The UK has a major role in the project and has scientists and engineers working on all the main experiments.

In the UK, engineers and scientists at 20 research sites are involved in designing and building equipment and analysing data. UK researchers are involved with all four of the main detectors and the computer GRID. British staff based at CERN has leading roles in managing and running the collider and detectors.

The total cost of building the LHC was approximately £3.74 billion, made up of three major components1:

  • The Accelerator (£3 billion)

  • The Experiments (£728 million)

  • The Computers (£17 million)

The total cost was shared mainly by CERN's 20 Member States, with significant contributions from the six observer nations.

The LHC project involved 111 nations in designing, building and testing equipment and software, and now continues with them participating in experiments and analysing data. The degree of involvement varies between countries, with some able to contribute more financial and human resource than others.

1 CERN, Ask an Expert


Charlotte Jamieson
UK CERN Liaison and Accelerator Programme Manager
Tel: +44 (0)1793 442 027

Anthony Davenport
Programme Support Manager
Tel: +44 (0)1793 442 004

Visit the CERN website
For media enquiries please telephone: +44 (0)1235 445 627

See also



13 images of Large Hadron Collider
The Big Bang
The Big Bang
Credit: CERN
520 646_th_4.jpg 646_web_4.jpg /646/646_web_4.jpg The Big Bang
LHC Computing Grid Globe
LHC Computing Grid Globe
Credit: CERN
521 646_th_5.jpg 646_web_5.jpg /646/646_web_5.jpg LHC Computing Grid Globe
Candidate Higgs to two-photon event in CMS render
Candidate Higgs to two-photon event in CMS rendered using SketchUp
Credit: CERN
650 646_th_6.jpg 646_web_6.png /646/646_web_6.png Candidate Higgs to two-photon event in CMS render
LHC dipole
3D cut of the LHC dipole
Credit: 2014 CERN
1026 646_th_7.jpg 646_web_7.jpg /646/646_web_7.jpg LHC dipole

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