The acronym CERN is also used to refer to the laboratory; in 2024, it had2,704 scientific, technical, and administrative staff members, and hosted about12,406 users from institutions in more than 80 countries.[8] In 2016, CERN generated 49petabytes of data.[9]
CERN's main function is to provide theparticle accelerators and other infrastructure needed for high-energy physics research – consequently, numerous experiments have been constructed at CERN through international collaborations. CERN is the site of theLarge Hadron Collider (LHC), the world's largest and highest-energy particle collider.[10] The main site atMeyrin hosts a large computing facility, which is primarily used to store and analyze data from experiments, as well as simulateevents. As researchers require remote access to these facilities, the lab has historically been a majorwide area network hub. CERN is also the birthplace of theWorld Wide Web.[11][12]
History
The convention establishing CERN[13] was ratified on 29 September 1954 by 12 countries in Western Europe.[14] The acronym CERN originally represented the French words forConseil Européen pour la Recherche Nucléaire ('European Council for Nuclear Research'), which was a provisional council for building the laboratory, established by 12 European governments in 1952. During these early years, the council worked at theUniversity of Copenhagen under the direction ofNiels Bohr before moving to its present site near Geneva.[15][16]
The acronym was retained for the new laboratory after the provisional council was dissolved, even though the name changed to the currentOrganisation européenne pour la recherche nucléaire ('European Organization for Nuclear Research') in 1954.[17][18] According toLew Kowarski, a former director of CERN, when the name was changed, the abbreviation could have become the awkward OERN,[19] andWerner Heisenberg said that this could "still be CERN even if the name is [not]".[20]
CERN's first president was SirBenjamin Lockspeiser.Edoardo Amaldi was the general secretary of CERN at its early stages when operations were still provisional, and the first Director-General (1954) wasFelix Bloch.[21]
The laboratory was originally devoted to the study ofatomic nuclei, but was soon applied tohigher-energy physics, concerned mainly with the study of interactions betweensubatomic particles. Therefore, the laboratory operated by CERN is commonly referred to as theEuropean laboratory for particle physics (Laboratoire européen pour la physique des particules), which better describes the research being performed there.[citation needed]
At the sixth session of the CERN Council in Paris from 29 June to 1 July 1953, the convention establishing the organization was signed, subject to ratification, by 12 states. The convention was gradually ratified by the 12 founding Member States: Belgium, Denmark, France, theFederal Republic of Germany, Greece, Italy, the Netherlands, Norway, Sweden, Switzerland, the United Kingdom, andYugoslavia.[23]
Scientific achievements
Several major achievements in particle physics have occurred in experiments at CERN. They include:
2012: The discovery of aboson with mass around125 GeV/c2 consistent with the long-soughtHiggs boson.[36][37][38]
In September 2011, CERN attracted media attention when theOPERA Collaboration reported the detection of possiblyfaster-than-light neutrinos.[39] Further tests showed that the results were flawed due to an incorrectly connectedGPS synchronization cable.[40]
The 1984Nobel Prize for Physics was awarded toCarlo Rubbia andSimon van der Meer for the developments that resulted in the discoveries of the W and Z bosons.[41] The 1992 Nobel Prize for Physics was awarded to CERN staff researcherGeorges Charpak "for his invention and development of particle detectors, in particular themultiwire proportional chamber". The 2013 Nobel Prize for Physics was awarded toFrançois Englert andPeter Higgs for the theoretical description of the Higgs mechanism in the year after the Higgs boson was found by CERN experiments.
In 1989, theWorld Wide Web was invented at CERN byTim Berners-Lee. Based on the concept ofhypertext, the idea was designed to facilitate information sharing between researchers.[43][44] This stemmed from Berners-Lee's earlier work at CERN on a database namedENQUIRE. A colleague,Robert Cailliau, became involved in 1990.[45][46][47]
In 1995, Berners-Lee and Cailliau were jointly honoured by theAssociation for Computing Machinery for their contributions to the development of the World Wide Web.[48] A copy of the first webpage, created by Berners-Lee, is still published on theWorld Wide Web Consortium's website as a historical document.[49] The first website was activated in 1991. On 30 April 1993, CERN announced that the World Wide Web would be free to anyone.[50] It became the dominant way through which most users interact with theInternet.[51][52]
CERN operates a network of seven accelerators and two decelerators, and some additional small accelerators. Each machine in the chain increases the energy of particle beams before delivering them to experiments or to the next more powerful accelerator. The decelerators naturally decrease the energy of particle beams before delivering them to experiments or further accelerators/decelerators. Before an experiment is able to use the network of accelerators, it must be approved by the variousScientific Committees of CERN.[54] Currently (as of 2022) active machines are the LHC accelerator and:
TheLINAC 3linear accelerator generating low energy particles. It provides heavy ions at 4.2 MeV/Da for injection into the Low Energy Ion Ring (LEIR).[55]
TheLinac4linear accelerator accelerates negative hydrogen ions to an energy of 160 eV. The ions are then injected to the Proton Synchrotron Booster (PSB) where both electrons are then stripped from each of the hydrogen ions and thus only the nucleus containing one proton remains. The protons are then used in experiments or accelerated further in other CERN accelerators. Linac4 serves as the source of all proton beams for CERN experiments.[58]
TheProton Synchrotron Booster increases the energy of particles generated by the proton linear accelerator before they are transferred to the other accelerators.[59]
The 28 GeVProton Synchrotron (PS), built during 1954–1959 and still operating as a feeder to the more powerfulSPS and to many of CERN's experiments.[60]
TheSuper Proton Synchrotron (SPS), a circular accelerator with a diameter of 2 kilometres built in a tunnel, which started operation in 1976. It was designed to deliver an energy of 300 GeV and was gradually upgraded to 450 GeV. As well as having its own beamlines for fixed-target experiments (currentlyCOMPASS andNA62), it has been operated as aproton–antiprotoncollider (the SppS collider), and for accelerating high energyelectrons andpositrons which were injected into theLarge Electron–Positron Collider (LEP). Since 2008, it has been used to inject protons andheavy ions into theLarge Hadron Collider (LHC).[61][62][63]
TheOn-Line Isotope Mass Separator (ISOLDE), which is used to studyunstable nuclei. The radioactive ions are produced by the impact of protons at an energy of 1.0–1.4 GeV from the Proton Synchrotron Booster. It was first commissioned in 1967 and was rebuilt with major upgrades in 1974 and 1992.[64]
TheExtra Low Energy Antiproton ring (ELENA), which takes antiprotons from AD and decelerates them into low energies (speeds) for use in antimatter experiments.
Many activities at CERN currently involve operating theLarge Hadron Collider (LHC) and the experiments for it. The LHC represents a large-scale, worldwide scientific cooperation project.[71]
The LHC tunnel is located 100 metres underground, in the region betweenGeneva International Airport and the nearbyJura mountains. The majority of its length is on the French side of the border. It uses the 27 km circumference circular tunnel previously occupied by theLarge Electron–Positron Collider (LEP), which was shut down in November 2000. CERN's existing PS/SPS accelerator complexes are used to pre-accelerate protons and lead ions which are then injected into the LHC.
Eight experiments (CMS,[72]ATLAS,[73]LHCb,[74]MoEDAL,[75]TOTEM,[76]LHCf,[77]FASER[78] andALICE[79]) are located along the collider; each of them studies particle collisions from a different aspect, and with different technologies. Construction for these experiments required an extraordinary engineering effort. For example, a specialcrane was rented from Belgium to lower pieces of the CMS detector into its cavern, since each piece weighed nearly2000 tons. The first of the approximately5000 magnets necessary for construction was lowered down a special shaft at in March 2005.
The LHC has begun to generate vast quantities of data, which CERN streams to laboratories around the world for distributed processing, making use of a specializedgrid infrastructure, theLHC Computing Grid. In April 2005, a trial successfully streamed 600 MB/s to seven different sites across the world.
In August 2008, the initial particle beams were injected into the LHC.[80] The first beam was circulated through the entire LHC on 10 September 2008,[81] but the system failed 10 days later because of a faulty magnet connection, and it was stopped for repairs on 19 September 2008.
The LHC resumed operation on 20 November 2009 by successfully circulating two beams, each with an energy of 3.5 teraelectronvolts (TeV). The challenge for the engineers was then to line up the two beams so that they smashed into each other. This is like "firing two needles across the Atlantic and getting them to hit each other" according toStephen Myers, director for accelerators and technology.
On 30 March 2010, the LHC successfully collided two proton beams with 3.5 TeV of energy per proton, resulting in a 7 TeV collision energy. This was enough to start the main research program, including the search for theHiggs boson. When the 7 TeV experimental period ended, the LHC increased to 8 TeV (4 TeV per proton) starting March 2012, and soon began particle collisions at that energy. In July 2012, CERN scientists announced the discovery of a new sub-atomic particle that was later confirmed to be theHiggs boson.[82]
In March 2013, CERN announced that the measurements performed on the newly found particle allowed it to conclude that it was a Higgs boson.[83] In early 2013, the LHC was deactivated for a two-year maintenance period, to strengthen the electrical connections between magnets inside the accelerator and for other upgrades.
On 5 April 2015, after two years of maintenance and consolidation, the LHC restarted for a second run. The first ramp to the record-breaking energy of 6.5 TeV was performed on 10 April 2015.[84][85] In 2016, the design collision rate was exceeded for the first time.[86] A second two-year period of shutdown begun at the end of 2018.[87][88]
Accelerators under construction
As of October 2019, the construction is on-going to upgrade the LHC's luminosity in a project calledHigh Luminosity LHC (HL–LHC). This project should see the LHC accelerator upgraded by 2026 to an order of magnitude higher luminosity.[89]
As part of the HL–LHC upgrade project, also other CERN accelerators and their subsystems are receiving upgrades. Among other work, the LINAC 2 linear accelerator injector was decommissioned and replaced by a new injector accelerator, theLINAC4.[90]
Decommissioned accelerators
The original linear acceleratorLINAC 1. Operated 1959–1992.[91]
TheLINAC 2 linear accelerator injector. Accelerated protons to 50 MeV for injection into the Proton Synchrotron Booster (PSB). Operated 1978–2018.[92]
The 600 MeVSynchro-Cyclotron (SC) which started operation in 1957 and was shut down in 1991. Was made into a public exhibition in 2012–2013.[93][94]
TheSuper Proton–Antiproton Synchrotron (SppS), operated 1981–1991.[97] A modification of Super Proton Synchrotron (SPS) to operate as a proton-antiproton collider.
TheLEP Pre-Injector (LPI) accelerator complex,[100] consisting of two accelerators, a linear accelerator calledLEP Injector Linac (LIL; itself consisting of two back-to-back linear accelerators called LIL V and LIL W) and a circular accelerator calledElectron Positron Accumulator (EPA).[101] The purpose of these accelerators was to inject positron and electron beams into the CERN accelerator complex (more precisely, to the Proton Synchrotron), to be delivered to LEP after many stages of acceleration. Operational 1987–2001; after the shutdown of LEP and the completion of experiments that were directly fed by the LPI, the LPI facility was adapted to be used for theCLIC Test Facility 3 (CTF3).[102]
TheAntiproton Accumulator (AA), built 1979–1980, operations ended in 1997 and the machine was dismantled. Stored antiprotons produced by the Proton Synchrotron (PS) for use in other experiments and accelerators (for example the ISR, SppS and LEAR). For later half of its working life operated in tandem withAntiproton Collector (AC), to form the Antiproton Accumulation Complex (AAC).[104]
TheCompact Linear Collider Test Facility 3 (CTF3), which studied feasibility for the future normal conducting linear collider project (theCLIC collider). In operation 2001–2016.[102] One of its beamlines has been converted, from 2017 on, into the new CERN Linear Electron Accelerator for Research (CLEAR) facility.
CERN, in collaboration with groups worldwide, is investigating two main concepts for future accelerators: A linear electron-positron collider with a new acceleration concept to increase the energy (CLIC) and a larger version of the LHC, a project currently namedFuture Circular Collider.[107]
CERN building 40 at the Meyrin siteThe interior of office building 40 at the Meyrin site. Building 40 hosts many offices for scientists from the CMS and ATLAS collaborations.
The smaller accelerators are on the mainMeyrin site, also known as the West Area, which was originally built in Switzerland alongside the French border, but has been extended to span the border since 1965. The French side is under Swiss jurisdiction and there is no obvious border within the site, apart from a line of marker stones.
The SPS and LEP/LHC tunnels are almost entirely outside the main site, and are mostly buried under French farmland and invisible from the surface. They have surface sites at points around them, either as the location of buildings associated with experiments or other facilities needed to operate the colliders such ascryogenic plants and access shafts. The experiments are located at the same underground level as the tunnels at these sites.
Three of these experimental sites are in France, with ATLAS in Switzerland, and some of the ancillary cryogenic and access sites are in Switzerland. The largest of the experimental sites is thePrévessin site, also known as the North Area, which is the target station for non-collider experiments on the SPS accelerator. Other sites are the ones which were used for theUA1,UA2 and the LEP experiments. The latter are used by LHC experiments.
Outside of the LEP and LHC experiments, most are officially named and numbered after the site where they were located. For example,NA32 was an experiment looking at the production of so-called "charmed" particles and located at the Prévessin (North Area) site.WA22 used theBig European Bubble Chamber (BEBC) at the Meyrin (West Area) site to examine neutrino interactions. TheUA1 andUA2 experiments were considered to be in the Underground Area, i.e. situated underground at sites on the SPS accelerator.
Since its foundation by 12 members in 1954, CERN regularly accepted new members. All new members have remained in the organization continuously since their accession, except Spain and Yugoslavia. Spain first joined CERN in 1961, withdrew in 1969, and rejoined in 1983. Yugoslavia was a founding member of CERN but quit in 1961. Of the 24 members, Israel joined CERN as a full member in January 2014,[108] becoming the first, and currently only, non-geographically European full member.[109]
The budget contributions of member states are computed based on their GDP.[110]
^12 founding members drafted theConvention for the Establishment of a European Organization for Nuclear Research which entered into force on 29 September 1954.[111][112]
Animated map showing changes in CERN membership from 1954 until 1999 (borders are as at dates of change)
Enlargement
Associate Members, Candidates:
Turkey signed an association agreement on 12 May 2014[133] and became an associate member on 6 May 2015.
Pakistan signed an association agreement on 19 December 2014[134] and became an associate member on 31 July 2015.[135][136]
Cyprus signed an association agreement on 5 October 2012 and became an associate member in the pre-stage to membership on 1 April 2016.[121]
Ukraine signed an association agreement on 3 October 2013. The agreement was ratified on 5 October 2016.[124]
India signed an association agreement on 21 November 2016.[137] The agreement was ratified on 16 January 2017.[125]
Slovenia was approved for admission as an Associate Member state in the pre-stage to membership on 16 December 2016.[138] The agreement was ratified on 4 July 2017.[139]
Lithuania was approved for admission as an Associate Member state on 16 June 2017. The association agreement was signed on 27 June 2017 and ratified on 8 January 2018.[140][126]
Croatia was approved for admission as an Associate Member state on 28 February 2019. The agreement was ratified on 10 October 2019.[127]
Latvia and CERN signed an associate membership agreement on 14 April 2021.[141] Latvia was formally admitted as an Associate Member on 2 August 2021.[128]
Brazil became the first associate member of the Americas on 13 March 2024, after signing the associate membership agreement in March 2022.[129]
Chile and Ireland were approved as new Associate Member States, subject to completion of the necessary accession and ratification processes in the countries on March 2025.[142]
A large number of institutes around the world areassociated to CERN through current collaboration agreements and/or historical links.[156] The list below contains organizations represented as observers to the CERN Council, organizations to which CERN is an observer and organizations based on the CERN model:
JINR, observer to CERN Council,[161] CERN is represented in the JINR Council.[162] JINR is currently suspended, due to the CERN Council Resolution of 25 March 2022.[146]
SESAME, CERN is an observer to the SESAME Council[163]
CERN has developed policies and official documents that enable and promote open science, starting with CERN's founding convention in 1953 which indicated that all its results are to be published or made generally available.[13] Since then, CERN published its open access policy in 2014,[171] which ensures that all publications by CERN authors will be published withgold open access and most recently an open data policy that was endorsed by the four main LHC collaborations (ALICE,ATLAS,CMS andLHCb).[172]
The open data policy complements the open access policy, addressing the public release of scientific data collected by LHC experiments after a suitable embargo period. Prior to this open data policy, guidelines for data preservation, access and reuse were implemented by each collaboration individually through their own policies which are updated when necessary.[173][174][175][176]
The European Strategy for Particle Physics, a document mandated by the CERN Council that forms the cornerstone of Europe's decision-making for the future of particle physics, was last updated in 2020 and affirmed the organisation's role within the open science landscape by stating: "The particle physics community should work with the relevant authorities to help shape the emerging consensus on open science to be adopted for publicly-funded research, and should then implement a policy of open science for the field".[177]
Beyond the policy level, CERN has established a variety of services and tools to enable and guide open science at CERN, and in particle physics more generally. On the publishing side, CERN has initiated and operates a global cooperative project, theSponsoring Consortium for Open Access Publishing in Particle Physics, SCOAP3, to convert scientific articles in high-energy physics to open access. In 2018, the SCOAP3 partnership represented 3,000+ libraries from 44 countries and 3 intergovernmental organizations who have worked collectively to convert research articles in high-energy physics across 11 leading journals in the discipline to open access.[178][179]
Public-facing results can be served by various CERN-based services depending on their use case: theCERN Open Data portal,[180]Zenodo, theCERN Document Server,[181]INSPIRE andHEPData[182] are the core services used by the researchers and community at CERN, as well as the wider high-energy physics community for the publication of their documents, data, software, multimedia, etc. CERN's efforts towards preservation and reproducible research are best represented by a suite of services addressing the entire physics analysis lifecycle, such as data, software and computing environment.CERN Analysis Preservation[183] helps researchers to preserve and document the various components of their physics analyses.REANA (Reusable Analyses)[184] enables the instantiating of preserved research data analyses on the cloud.
The CERN Science Gateway, opened in October 2023,[186] is CERN's latest facility for science outreach and education. It is home to a range of immersive exhibits, workshops, and shows.
TheMicrocosm museum previously hosted another on-site exhibition onparticle physics and CERN history. It closed permanently on 18 September 2022, in preparation for the installation of the exhibitions in Science Gateway.[187]
CERN also provides daily tours to certain facilities such as the Synchro-cyclotron (CERNs first particle accelerator) and the superconducting magnet workshop.
In 2004, a two-metre statue of theNataraja, the dancing form of the Hindu godShiva, was unveiled at CERN. The statue, symbolizing Shiva's cosmic dance of creation and destruction, was presented by theIndian government to celebrate the research center's long association with India.[188] A special plaque next to the statue explains the metaphor of Shiva's cosmic dance with quotations from physicistFritjof Capra:
Hundreds of years ago, Indian artists created visual images of dancing Shivas in a beautiful series of bronzes. In our time, physicists have used the most advanced technology to portray the patterns of the cosmic dance. The metaphor of the cosmic dance thus unifies ancient mythology, religious art and modern physics.[189]
Arts at CERN
CERN launched its Cultural Policy for engaging with the arts in 2011.[190][191] The initiative provided the essential framework and foundations for establishingArts at CERN, the arts programme of the Laboratory.
Since 2012, Arts at CERN has fostered creative dialogue between art and physics through residencies, art commissions, exhibitions and events. Artists across all creative disciplines have been invited to CERN to experience how fundamental science pursues the big questions about our universe.
Even before the arts programme officially started, several highly regarded artists visited the laboratory, drawn to physics and fundamental science. In 1972,James Lee Byars was the first artist to visit the laboratory and the only one, so far, to feature on the cover of the CERN Courier.[192]Mariko Mori,[193]Gianni Motti [fr],[194]Cerith Wyn Evans,[195]John Berger[196] andAnselm Kiefer[197] are among the artists who came to CERN in the years that followed.
The programmes of Arts at CERN are structured according to their values and vision to create bridges between cultures. Each programme is designed and formed in collaboration with cultural institutions, other partner laboratories, countries, cities and artistic communities eager to connect with CERN's research, support their activities, and contribute to a global network of art and science.
They comprise research-led artistic residencies that take place on-site or remotely. More than 200 artists from 80 countries have participated in the residencies to expand their creative practices at the Laboratory, benefiting from the involvement of 400 physicists, engineers and CERN staff. Between 500 and 800 applications are received every year. The programmes comprise Collide, the international residency programme organised in partnership with a city; Connect, a programme of residencies to foster experimentation in art and science at CERN and in scientific organisations worldwide in collaboration withPro Helvetia, and Guest Artists, a short stay for artists to stay to engage with CERN's research and community.[198][199]
In popular culture
The statue ofShiva engaging in theNataraja dance (symbolising his cosmic dance of creation and destruction) presented by theDepartment of Atomic Energy of IndiaGeneva tram 18 at CERN
The bandLes Horribles Cernettes was founded by women from CERN. The name was chosen so to have the same initials as the LHC.[200][201]
The science journalistKatherine McAlpine made arap video called "Large Hadron Rap" about CERN's Large Hadron Collider with some of the facility's staff.[202][203]
Particle Fever, a 2013 documentary, explores CERN throughout the inside and depicts the events surrounding the 2012 discovery of theHiggs Boson.
CERN is depicted in thevisual novel/anime seriesSteins;Gate as SERN, a shadowy organization that has been researching time travel in order to restructure and control the world.[205]
InRobert J. Sawyer's 1999 science fiction novelFlashforward, as CERN's Large Hadron Collider accelerator is performing a run to search for the Higgs boson the entire human race sees themselves twenty-one years and six months in the future.
CERN is depicted in a 2009 episode ofSouth Park (Season 13, Episode 6), "Pinewood Derby". Randy Marsh, the father of one of the main characters, breaks into the "Hadron Particle Super Collider in Switzerland" and steals a "superconducting bending magnet created for use in tests with particle acceleration" to use in his son Stan's Pinewood Derby racer.[209]
In the 2010 season 3 episode 15 of the TV situation comedyThe Big Bang Theory, "The Large Hadron Collision",Leonard andRaj travel to CERN to attend a conference and see the LHC.
The 2012 student filmDecay, which centres on the idea of the Large Hadron Collider transforming people into zombies, was filmed on location in CERN's maintenance tunnels.[210]
The Compact Muon Solenoid at CERN was used as the basis for theMegadeth'sSuper Collider album cover.
In 2015, Sarah Charley, US communications manager for LHC experiments at CERN with graduate students Jesse Heilman of theUniversity of California, Riverside, and Tom Perry and Laser Seymour Kaplan of theUniversity of Wisconsin, Madison created a parody video based on "Collide", a song by American artistHowie Day.[212] The lyrics were changed to be from the perspective of a proton in the Large Hadron Collider. After seeing the parody, Day re-recorded the song with the new lyrics, and released a new version of "Collide" in February 2017 with a video created during his visit to CERN.[213]
In 2015,Ryoji Ikeda created an art installation called "Supersymmetry" based on his experience as a resident artist at CERN.[214]
In the 2017 season 10 episode 6 of the British science fictionDoctor Who, "Extremis", CERN is one of several locations found to be connected by a hub of mysterious portals.
The television seriesMr. Robot features a secretive, underground project apparatus that resembles theATLAS experiment.
Parallels, aDisney+ television series released in March 2022, includes a particle-physics laboratory at the French-Swiss border called "ERN". Various accelerators and facilities at CERN are referenced during the show, including ATLAS, CMS, the Antiproton Decelerator, and the FCC.[215][216][217]
^Hermann, Armin; Belloni, Lanfranco; Krige, John (1987).History of CERN. European Organization for Nuclear Research. Amsterdam: North-Holland Physics Pub.ISBN0-444-87037-7.OCLC14692480.
^"30 years of the web: a short history of the invention that changed the world".British Council. Retrieved19 September 2025.Berners-Lee and others worked to ensure that CERN would make the underlying code available on a royalty-free basis, forever. This decision was announced in April 1993, and sparked a global wave of creativity, collaboration and innovation.
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